The Evolution of the Submarine
The submarine came into its own during World War I, it’s devastating lethality and near-invincibility reinforced during and after World War II, and its nuclear propulsion and teeth giving it virtually limitless range and calamitous destructive power during the post-World War II years. However, it made a fairly late entry into India's naval fleet, possibly because the submarine was earlier considered an 'offensive' weapon platform and hence could not have a place in the arsenal of a country that had pledged to abide by the principles of peace.
Since the capability to operate in the third element - me subsurface -has now been added to the Indian Navy's repertoire, it is essential that the evolution of the submarine from its tentative conceptual state in the 16tR: century to its present day status of being the prime dealer of destruction at sea, as well as the significant role it played in shaping the ends of the two World Wars, be studied in detail before apprising oneself of the process of establishment of the submarine arm in the Indian Navy. This chapter provides a brief resume of such developments around the globe.
While addressing the men of the Royal Navy's Submarine Service during World War II, Winston Churchill had said; 'Of all the branches of men in the Forces, there is none that shows more devotion and faces greater perils than the submariner . . . great deeds are done in the air and on the land, nevertheless nothing surpasses your exploits.' Indeed, nothing can transcend the tour de force that the submarine has displayed and the impact of the revolutionary changes in the concept; both strategic arid tactical, of the war at sea brought about by its invention. Besides, its use for opera-ions against a wide variety of targets during the last century have been far greater than that of the supersession of the oared galley by the sailing galleon, the sailing ship of the line by the steam ironclad, the battleship by the carrier-borne and shore-based maritime aircraft, and the diesel-electric propulsion systems of submarines, by the nuclear power plant.
Adoption of new techniques, technology, strategy or tactics, weaponry and weapon platforms generally require a fairly long lead time because their potential and advantages over the existing techniques, tactics, etc, have to be convincingly established before they are introduced in any Service. Oared galleys continued to be constructed for England's Navy for several years after the defeat of the Spanish Armada; even thirty years after the first battleship had been fitted with engines, steam ironclads continued to be equipped with sails, and when World War II was coming to an end in 1945, the British Admiralty was still working on a new design for a 16-inch gun turret. For similar reasons, despite the developments in submarine technology in Europe and America concurrently with those in Great Britain, the Royal Navy woke up to the danger posed by submarines only after the outbreak of World War I when the armored cruisers, Cressy, Hoque and Aboukir, were sunk by one small German U-boat as a result of which the Grand Fleet's method of cruising the sea had to be drastically altered. J& fact, until the time they learnt their lessons the hard way, the British had been doing their best to discourage the development of submarines because they still believed that they, with their huge surface navy, had nothing to gain and much to lose by their development. As a result of the adoption of this attitude, the design of the first submarine for the Royal Navy had to be purchased from America for construction in Britain and, what is even more surprising, this class of submarines were built not to supplement the British war effort but only to enable the British designers to find an antidote to them! It is significant to note that until October 1, 1901, when the Royal Navy's Submarine Service came into being with the launching of Submarine No, 1(129 tons), the popular view in Britain, which has a seafaring history spanning several millennia, was that submarines were 'underhand, unfair and damned un-English'.
This is of course not surprising as there is no profession so wedded to tradition as the military. During World War I the machine gun had been scorned as the 'much-overrated weapon'; the tank was thought of as a 'toy'; Marshal Joffre had refused to have a telephone installed in his office; poison gas was reluctantly adopted by the British after its use by the Germans was classified as a mere 'accessory'; the trench mortar was projected twice by the British War Office and was finally accepted after a cabinet minister secured the funds for it from an Indian maharaja; British subalterns got 'their swords sharpened before crossing to France; and as late as 1918 ‘Pershing had cluttered up his supply lines with mountains of fodder for useless horses, still dreaming of Custer and Sheridan and the glint of Virginia moonlight on the shirting saddles of Stuart's cavalry.’
Early History
There are occasional references in ancient history to the attempts made by man to seek stealth and surprise by operating from submerged or semi- submerged vessels during wars at sea. The very early protagonists of the submarine were not so much inspired by the desire to descend below the surface of the sea to explore the depths of the sea as to devise a method of rendering a warship invisible to the enemy so that it could carry out surreptitious attacks and escape at will.
The earliest reference to attempts made at waging underwater warfare is found in the writings of Aristotle who recorded that Alexander the Great used diving bells to enable his men to descend below the surface of the sea during the siege of Tyre in 332 B.C. He also ordered his divers to impede or destroy the defensive barriers still in use and known as boom defenses) the city was likely to build to prevent the movement of submerged vessels. In fact, according to legend, Alexander himself made a descent into the sea in a device which kept its occupants dry and admitted light-However it is believed that nearly a century earlier than Alexander's experiments; the Athenians had used divers to clear the entrance to the Syracuse harbour during its siege from 415 to 413 B.C.
Over the following two millennia the potential and the tactical advantages of operating below the surface of the sea continued to be appreciated by many military thinkers and several attempts were made during this period to develop an underwater platform that could be used against enemy shipping and war vessels far more effectively than surface ships, both for offensive and defensive operations. In the 16th century, during the Renaissance, Leonardo da Vinci, is said to have designed a vessel which could dive, remain submerged for some time and surface unaided end could surreptitiously plant bombs or mines on enemy vessels, but the design of this submarine was kept secret because da Vinci he felt that man would misuse it- 'He knew a method of remaining a long time underwater, but he refused to tell of it because of the "evil nature of man”.
The Submersible Takes Shape
Experiments in diving and moving underwater continued but the first recorded mention of a submarine design conforming to the basic principles of submersion is found in the writings of a British naval officer, William Bourne, who published a detailed design of a 'boat that may go under the water' in 1578. The vessel was a completely enclosed boat which could be submerged by reducing its volume by contracting the sides through the use of hand vices, which could bring the boat back to the surface by increasing the volume. This vessel could also move underwater by using watertight oars. This realistic design provided for both submersibility and propulsion underwater but was never built.
Twenty-seven years later, in 1605, using a design similar to Bourne's, Magnus Pegelius constructed a submersible boat but due to the viscosity and adhesive properties of underwater mud the craft never surfaced after diving.
In 1620, a Dutch physician, Cornelius van Drebel, built a submarine and successfully conducted trials in the Thames River, making the craft cruise repeatedly on the surface, dive, maneuver underwater and then surface for several hours at a stretch. He later built two more craft, embodying the same principles, but larger in size. Van Drebel’s craft had an outer hull made of greased leather stretched over a wooden framework. Propulsion was provided, both on the surface and while submerged, by oars which extended through the sides and which were sealed and rendered watertight with tight-fitting leather flaps which allowed free transverse movement while anchoring the oars to the hull. The underwater endurance of the submarine crew was sought to be enhanced by using compressed oxygen to 'restore to the troubled air such portion of vital parts as would make it again, for a good while, fit for respiration/After repeated trials in the Thames river had established the capabilities of the new 'boat' in travelling on the surface and maneuvering underwater at depths of 12 to 15 feet, King James I is reported to have taken a trip in one of the larger models to demonstrate its safety. But despite the conclusive proof of the designers having evolved a powerful two-dimension weapon platform, the novel features of the submarine failed to arouse the interest of the British Navy.
The wars in the 17th century in Europe, however, Jed to a proliferation of submarine designs some of which were the work of men from professions other than those associated with the navy or seafaring; in fact some of the designers were men of peace, i.e., priests and monks! One such designer was Oliver Cromwell's brother-in-law, John Wilkins, Bishop of London. His device for jettisoning gash through an underwater lock while remaining submerged led to the development of underwater lavatories in the latter-day submarines which obviated the need for the submarine to surface repeatedly. He also wrote on future naval developments and centuries later many of his predictions turned out to be true; such as his prediction of journeys by submarines under the Polar ice-cap, an idea which was dismissed as science fantasy In the 17th century.
By the middle of the 17th century, many naval architects had conceptualized and experimented with possible submersible weapon platforms. In 1653, a Frenchman, de Son, designed and built a 72-foot submarine 'that doeth undertake in one day to sink 100 ships' but his submarine never sailed, as its prime mover, a clockwork device, was not powerful enough to propel it on the surface or underwater.
The earlier decades of the 18th century saw numerous 'underwater boats' built, the British designers alone having patented no fewer than fourteen types by 1727. The concept of using a ballast tank for submerging and diving was first visualized by an inventor who described his design in the Gentleman's Magazine ml747. The hull of his craft was equipped with a bank of goatskins which would be filled with water to make the vessel submerge and a 'twisting rod' would be used to force the water out of the goatskins which would provide positive buoyancy and bring the Vessel back to the surface. This craft, however, was never built. At this time the mechanical and physical principles involved in diving and surfacing were yet to be fully understood and hence many of the ideas put forward turned out to be impractical, fanciful or, in some cases, even grotesque. Besides the lack of understanding of the principles, the general impression at this time was that it would be impossible to navigate a craft underwater and even if it became possible, its tactical advantages in naval warfare would be minimal.
The First Submarine, Bushnell's Turtle
However, developments of a submersible craft with weapon delivery capability received a shot in the arm in 1776 when the first submarine that could dive, surface, cruise -both on the surface and underwater-and plant explosives on enemy vessels while remaining submerged, made a dramatic appearance during the American War of Independence. David Bushnell, an American farmer's son, had developed the technique of exploding gunpowder underwater and had followed it up with the invention of the first one-man submersible that was to be used as a weapon platform, the Turtle. Shaped like a wooden beer-barrel, it was powered by a hand-operated screw propeller which could move it at a speed of three knots. It could stay submerged for 30 minutes during which it had to approach its target underwater, plant an explosive on its hull and get away.
It was on September 6, 1776, 29 years before the Battle of Trafalgar, that Ezra Lee, a sergeant in the American Revolutionary Army and the first submariner to launch an underwater operation against enemy vessels, undertook to scuttle Eagle, the Flagship of the British Fleet which was blockading New York Harbour, by planting a powerful explosive on its hull. He set off on his historic mission all by himself on board the Turtle and, operating the handle of the screw-propeller hard for several hours, reached the Eagle and dived. The Turtle then got under the hull of the Flagship and Lee tried to bore a screw device into the Eagle's hull for securing the explosive device to it. Later, a pre-set clockwork mechanism would trigger the explosive device. Unfortunately for Lee, the wooden hull of the Flagship had a sheathing of copper for reinforcement and prevention of the formation of any marine growth. Despite repeated attempts, Lee failed to penetrate the hull. He persisted with his efforts to plant the device, but soon the effects of carbon dioxide poisoning overwhelmed him. He then withdrew, surfaced and set course for shore but was spotted and pursued by a British patrol-beat. Lee jettisoned the explosive cargo and it went off, almost blowing the patrol-boat out of the water.
The Commander of the British Fleet soon realised that his Flagship had had a narrow escape and ordered the blockading ships of his fleet to withdraw to the outer harbour, where they were comparatively safer, but the effectiveness of the blockade was considerably reduced. Thus while the first sub-surface attack in. the history of submarines had proved to be abortive, it brought home one lesson which holds good even today- that the mere presence of a submarine lurking below the surface can upset the plans of a tactical commander over a large area far more than the sinking of a ship. In other words, the fear of the unknown and the element of surprise area greater deterrent at sea than an actual attack. Submarine warfare thus became a reality, even though the first ever submarine attack had failed to cause any physical damage.
Fulton's Nautilus
Robert Fulton, the American inventor who was the first to propel a boat by steam in 1803, and the first to build a steam warship, the Fulton, in 1815, is better remembered for having constructed a three-man submarine boat, the Nautilus, in 1795. Incorporating nearly all the main features of a modem submarine and shaped like one, the Nautilus, which was built of steel and shaped like an elongated oval, was powered by sails on the surface and by a hand-driven screw-propeller under water. Since the periscope was yet to be invented, a primitive form or a conning tower, equipped with a watertight port hole was provided and was used for observation and maneuvering the craft underwater. It was also equipped with ballast tanks for diving and surfacing, as modern submarines are, and had a submerged endurance of three hours for four men to breathe and two candles to bum! Like the Turtle, it had a device which could attach explosives to the hull of a ship while remaining underwater. During its trials at Brest, the Nautilus had also proved its capabilities by sinking an old schooner.
Since the war was over, the American naval authorities showed little interest in Fulton's submarine design, compelling him to build the Nautilus at Paris. He offered it to the authorities to deploy it off the French coast against British warships but it failed to sink or damage any ship.
Disappointed, Fulton then approached the British authorities and demonstrated the capability of his submarine craft by sinking a ship in 1804. The Prime Minister, William Pitt, was so impressed by the submarines performance that he asked the Admiralty to acquire the craft. His request was, however, dismissed by the First Sea Lord (then Earl St. Vincent) with the rather intemperate remark, 'Pitt was the greatest fool that ever existed to encourage a mode of war which those who command the sea do not want and, if successful, will deprive them of it/
For about 60 years after the disappearance of the Nautilus, inventors continued to test various designs of small, hand-propelled submersibles with a crew of six to eight men. None of these was, however, an improvement on Fulton's craft, and hence no progress towards further development of submersibles was discernible. However, during the American Civil War the next nautical milestone in submarine development was recorded, with the sinking of a warship by a submarine, when a Federal corvette, the Housatonic, which v/as blockading Charleston harbour, was scuttled by the Confederate submersible David (according to the Encyclopedia Britannica, the name of the submersible was Hartley) in 1864. An explosive pack, suspended ahead of the bow of the David from a bowsprit, accomplished the feat when the submersible rammed the corvette. However, when the Housatonic was salvaged, the mangled wreck of the David was found sandwiched between the corvette's hull and the seabed. Because of the submersible's proximity to the Housatonic, the explosive had proved to be as much of a danger to the attacker as to its target. The Housatonic thus had the dubious honour of being the first surface vessel to be sunk by a submarine (and the first surface vessel to have crushed a submarine in an unintended Kamikaze attack).
Progress in submarine development continued to be bedeviled by the absence of a suitable propulsion device to enable the submarine to operate underwater for long periods, and an explosive which, rather than being planted, could be launched or fired by the submarine from a safe distance.
Steam and Electric Propulsion
Steam engines, though bulky and messy, were tried for some time for the propulsion of submersibles and in 1880, George Garret, an English clergyman, built a submarine which was propelled by two propellers driven by steam from a coal-fired boiler, which featured a retractable smokestack for ventilation. About this time, a Swedish gun designer, Norden felt, also constructed a submarine powered by steam. This submarine was capable of submerging to a depth of 50 feet, had an underwater endurance of 20 miles and was the first submersible to be fitted with a practical torpedo tube. The novelty of the new weapon-launching device appealed to the Turks and Russians, who acquired some of these craft but, because of their limitations, could not achieve anything worthwhile.
Experiments with the still new form of energy, electricity, had in the mean time proved successful, and storage batteries with several hours of endurance had been developed for the propulsion of submarines with electric motors. In 1886 two Englishmen, Campbell and Ash, developed an all-electric submarine which was powered by two 50-horse-power motors operated from a 100-cell storage battery. It was capable of maintaining a surface speed of six knots but the storage capacity of its battery being very low, its effective range was limited to only 80 miles.
The endurance of the storage battery for submarines was considerably improved by a Frenchman, Claude Gombat who, between 1888 and 1890, built some small battery-powered submarines which were acquired and used by the French Navy for about 10 years. These submarines were about 160 feet long, had a maximum speed of 13.5 knots and an effective range of 200 miles.
The 'Holland Type' Submarine -Ballast Tanks and Hydroplanes
Meanwhile John P. Holland of New Jersey, an ex-Irish school teacher who had migrated to the USA and who was to virtually become the creator of the Royal Navy's submarine service, had launched his first submersible in 1875. In 1882 he constructed the Fenian Ram which was tested on the Hudson River, and which was propelled by gasoline engines en the surface and electric motors underwater. These submersibles had several features which had to be discarded later, but some of Holland's innovations, perfected during the following years, have been incorporated in the latter-day submarine design. Of these, the most important are the use of ballast tanks for submerging and surfacing, and horizontal rudders or hydroplanes for maneuvering the craft in the vertical plane for depth control.
For some years Holland and Nordenfelt were vying with each other for an order from the United States Government for building a submarine and it finally went to the former in 1895. The vessel that was designed, the Plunger, was to be powered by a coal-fired steam engine on the surface, and battery-operated twin motors under water. Numerous designing defects came to light during construction and the craft was eventually abandoned. A new model, Holland's ninth, was built in his shipyard and delivered to the United States Government in 1900 and was used as the basic design for all the submarines that were built subsequently. This submarine, which was launched in 1897 and which was tested for three years before delivery, was named the Holland.
A contemporary of Holland, Max Lanbeuf of France, also built a submarine, Nerval, which was similar in construction to Holland's submarines and it was also powered by a coal-fired steam engine but, instead of tanks, it used the space enclosed in its double hull for ballast.
Internal Combustion Engine
The submarines of Holland and Lanbeuf were the prototypes for submarines built for several decades thereafter and they had almost all the essential features of modern day conventional submarine -ballast tanks, internal combustion engines for surface propulsion at nine knots and for charging batteries whilst on the surface and electric motors for underwater propulsion at seven knots; Us effective operational range was an impressive 1,000 miles. However, the internal combustion engines used at that time were gasoline engines which were a fire hazard because they gave off highly noxious and inflammable gasoline fumes, and, later were replaced by diesel engines developed by the German engineer, Rudolph Diesel, during the last decade of the 19th century.
Another submarine designer, Simon Lake, had built a submarine, the Argonaut Junior, in 1894 which was primarily meant for use in such peacetime operations as the exploration and exploitation of the living and mineral wealth below the surface of the sea and under the seabed, and for commercial salvage operations. The submersible was made of two layers of yellow pine with a sheet of canvas between them to render it impervious to water. This submarine could move about on the seabed and had an air-lock device which permitted its crew, using diving helmets, to emerge from the submarine and explore the surroundings.
In 1897, Lake built his second submarine, the Argonaut, which was powered by a 30-horse-power gasoline engine, had a 36-foot cigar-shaped hull and could submerge to the bed of a river or the bottom of a lake and move along the bed on three wheels which could be retracted and housed in the keel when the submersible was navigated. A year later, i.e., in November 1898, the Argonaut had the honour of being the first submarine to cross the Atlantic when she sailed from Norfolk and, despite heavy storms encountered on the way, reached New York.
Another submarine, the Protector, was built by Lake in 1906 and sold to Russia. After it was tested and accepted in Russia, he built several more, submersibles for the Russian Government.
The French Submarine -The Gustav Zede
Claude Gombat, a Frenchman, built some small but effective submarines between 1888 and 1890. One of these, the Gustav Zede, which was in service with the French Navy for over ten years, had a hull 160 feet long, was powered by storage batteries and had a range of 200 miles at a cruising speed of six knots and a maximum speed of 13.5 knots.
In 1901, this submarine, while taking part in exercises, staged a mock attack on the French Mediterranean Fleet after travelling 160 miles under her own power. While remaining totally undetected, the submarine hit the battleship Charles Martel, the pride of the French Navy, with a dummy torpedo. The successful 'sinking' of a fully protected battleship by a tiny submarine which could approach its target, deliver a lethal blow and escape without being detected, was a watershed in the history of submarines and was an object lesson to the naval planners of all major countries, in the changes that were going to be wrought into the future shape of sea power.
By the end of the 19th century, only six navies in the world had acquired a total of 10 submarines and eleven more were being built. Leading the submarine-owning countries was France, which had a total of 14, built or building, followed way behind by the United States which had only two, one of these two being of the Holland-type which was at that time reckoned to be the best design in the world. The other countries which had acquired submarines were Italy, Portugal, Spain and Turkey which had one craft each. Britain, which had one of the mightiest navies at that time, was yet to acquire one because of active and continued discouragement from the British Admiralty.
The 1901 success of the French submarine, Gustav Zede, however, came as a rude shock and an eye-opener to the mandarins of the Admiralty, and so it overruled the policy of the First Sea Lord, Earl St. Vincent, and promptly ordered five submarines of the Holland type of the US Navy -not for using them against enemy warships or for coastal defense- but for intensive research into antisubmarine measures! The first submarine built for the Royal Navy, Submarine No. 1 (with only one torpedo cube) was thus launched on October 2, 1901 and the submarine service of the Royal Navy was born.
Submarines for the British Navy -Acute Submarine-Phobia
The policy of active discouragement against submarine development had prevailed in the British Admiralty for about a century. Hence there had been practically no research in submarine development in England during the 19th century. As a consequence the design for the first submarine for the Royal Navy had to be acquired from the USA. In trying to perpetuate this bias, even as this submarine was being commissioned, the Admiralty had decided to curtail the formalities associated with the commissioning of the new vessel to the minimum. To quote an official notice reproduced in the journal Naval and Military Record of October 3, 1901, the day after the launching: It is understood that no ceremony will take place at the forthcoming launch of the first British submarine at Barrow-in-Furness. The Admiralty regard these boats as wholly in the nature of an experiment and, like all other experiments conducted from time to time, this one will be carried out with all privacy.
Despite the official stance against the development of the underwater craft, shipbuilders in Britain had actually started building submarines as early as in 1885 - full sixteen years before the construction of the first submarine for the Royal Navy. In that year work had commenced on me construction of an experimental submarine at the Barrow- in-Furness shipyard. This submarine, which had a 100-foot hull, had been built in sections by 1886, sold to the Turkish Government, shipped out to that country, and assembled there for the Turkish Navy. Soon, another submarine, 123 feet long, was built at Barrow and sold to the Imperial Russian Navy. It is interesting to note that 'underhand, unfair and un-English' warfare wasn't acceptable to Britain but others could indulge in it so long as it yielded lucre for her!
After building five Holland-type submarines, Britain built the first A-class submarine (with one torpedo tube) in 1902, B-class (with two torpedo tubes) in 1905, C-class (with two torpedo tubes) in 1906, D-class (with three torpedo tubes, one tube being in the stern, and a 12-pounder gun) in 1908, and E-class (with five torpedo tubes, and one six-pounder or four-inch gun) in 1913. The B-class was the first to be fitted with surface weapons, and the D-class was the first to be equipped with a diesel engine and stern torpedo tube -all earlier classes having used gasoline engines for propulsion, and being fitted with forward torpedo tubes.
The submarine-phobia and surface-vessel mania of the British Admiralty, even after submarines had begun to the built for the Royal Navy, is evident from what Captain Hugh Oliphant, who was the Commanding Officer of Dolphin, the Royal Navy's submarine training establishment, and Captain, First Submarine Squadron some years ago, said about the prevailing ambience at that time: 'One serving British Admiral was at that moment publicly demanding that submarine crews (captured) in war should be treated as pirates and hung; the Director of Naval Construction was warning non-expendable senior officers "never to go below water", and the Engineer-in-Chief considered that the running of a petrol engine in a confined space was so dangerous that the first submarine moorings in Portsmouth were among the remote quarantine and powder hulks’. The first submarine 'depot ship' and training school was thus given the not inappropriate name of Hazard’.
By now, even in the Royal Navy, some of the senior officers had realized the potential of the submarine and were quite vociferous in demanding a change in the naval policy. In 1904, Admiral Lord Jacky Fisher wrote prophetically:
It is astounding to me, perfectly astounding, how the very best amongst us absolutely fail to realize the vast impending revolution in naval warfare and naval strategy that the submarine will accomplish!'
Here, just to take a simple instance, with the battleship Empress of India, engaged in maneuvers and knowing the proximity of submarines, so self-confident of safety and so oblivious of the possibilities of modern warfare.. . and suddenly they see a Whitehead torpedo miss her stern by a few feet!
And how fired? From a submarine of the 'pre-Adamite' period; small, slow, badly fitted, with no periscope at all.
. . . . I have not disguised my opinion in season and out of season as to the essential, imperative, immediate, vital pressing, urgent (I can't think of any more adjectives) necessity for more submarines at once, at the very least 25 in addition to those now ordered and building and 100 more as soon as practical, or we shall be caught with our breeches down....
The turn of the century was thus a watershed in the history of submarines, for the fundamental principles of the construction and operation of submersibles had taken, concrete shape and been demonstrated to the world by this time. It continues to be valid even today. Internal combustion engines, both gasoline and diesel, had proved to be the most efficient and practical power plants; electric propulsion, as an alternative or in tandem with diesel or gasoline engines, had proved a success; the invention of the periscope had increased the feasibility of underwater navigation and improved the potential of the submarine for surveillance and for carrying out attacks while remaining submerged; and the torpedo, the primary weapon of the submarine, had been perfected and had proved its deadly capability. The manually propelled and operated one-man submersibles had been replaced by the larger and more versatile, long-range and long-endurance submarine. These would soon become a major component of naval strategy, both for offence and defense. Anew chapter had begun in the history of naval warfare.
Special Features of Submarines Developed
Some of the features peculiar to these submarines were the all-welded hull, the periscope, the schnorkel or the snort, the diesel-electric propulsion system and the revolutionary weapon - the torpedo.
Below the superstructure deck was the hull which had to withstand the tremendous pressure of sea water while submerged, and to maintain its watertight integrity under varying pressure conditions. The shape of the vessel had evolved from Bushnell's spherical Turtle to the cylindrical Holland genre over a period of 125 years, the latter being constructed on the basis of the fabrication of a series of watertight containers by means of watertight joints. In the double-hull type of submarines, the pressure hull was inside the outer hull and between these hulls were the water and fuel oil tanks.
The space between the non watertight superstructure deck and the pressure hull was used as locker space for stowing anchor gear, lines, ammunition for the submarine guns, boats and other equipment that did not get damaged by immersion in Water. Extending upwards through the superstructure amidships was a watertight tower known as the conning tower, the top of which was the bridge from where the vessel was controlled when on the surface. But when submerged, it was controlled from the conning tower or from a compartment directly below it, known as the control room. For making observations while totally submerged, periscopes extending above the bridge were operated from the conning tower.
Evolution of the Torpedo
The submarine is essentially a torpedo vessel, launching Its torpedoes while surfaced or submerged, and hence it has basically evolved over the years as a torpedo-launching platform, though today its weapon outfit includes missiles. The torpedo too has been developed into a highly complicated underwater projectile with a heavy explosive charge. It is detonated by an exploding mechanism when in contact with, or in proximity to, the hulls of target vessels. Today, high-power engines drive it at high speed and sophisticated instruments control its course. Torpedoes are fired by, or launched by, surface vessels, aircraft or submarines. Its capability of being launched, approaching the target and striking with little or no warning makes it particularly useful to submarines, which can frequently carry out an attack and escape without being detected.
The word torpedo is derived from the word Torpedinidae, the family name for the fish called electric rays. These fish and electric eels have been referred to as torpedoes. The term torpedo was first applied to an explosive device around 1800 and, in its various experimental forms, this name was used for the next 65 years or so for a type of floating mine.
The first to use an explosive device of this category was David Bushnell in 1776. His was a simple type of floating mine with a clockwork mechanism which was designed tc be secured to the bottom of an enemy vessel with the help of a screw driven into the latter's hull, and to go off after the pre-set interval. As described earlier, no damage was caused to the target, the British warship Eagle, as the submersible, Turtle failed to secure the explosive device to the ship's hull.
Robert Fulton, the American genius whose talents had been recognized not at home but in France and England, used 'a catamaran torpedo' developed by him in an attack on the French Fleet at Boulogne on October 2,1804. Twelve of these devices were turned loose against the French ships, creating great excitement but causing no damage as they exploded short of their intended targets.
During the American Civil War, various kinds of torpedoes were used by the Union and Confederate forces. Some of these were simple beer kegs filled with gunpowder whose use was responsible for the well-known outburst from Admiral David Farragut, 'Damn the torpedoes... Go ahead!' At the other extreme were the gigantic electric torpedoes carrying over 90 kilograms of explosives each, one of which was used to blow the Federal gunboat Commodore Jones to smithereens.
It was an English engineer, Robert Whitehead, who, in 1868, perfected the first practical self-propelled torpedo, the forerunner of the modern torpedo. The Whitehead torpedo used all the basic principles that are used even today, such as hydrostatic depth control lateral control, and an engine which powered two contra-rotating propellers; the source of power for the 'cold-running' torpedo was compressed air contained in a metal flask which produced a speed of seven knots over a range of 700 yards. During the last decade of the 19th century, the US Navy used this torpedo, its speed increased to 27 knots though its range had been extended only by 300 yards.
The first 'hot-running' version, the Bliss-Levitt torpedo, was designed by an American, E.W. Bliss, in 1904 and featured a combustion chamber burning alcohol, preheated from the flask in which the pressure was increased. The combination of higher pressure and preheating increased the range to 4,000 yards.
Meanwhile, the introduction of torpedoes had radically changed naval warfare. In 1877, a superior Turkish naval formation was forced to keep clear of the Russians off Odessa because the latter had equipped its ships with torpedoes. With their rabidly increasing speed, range and hitting power, torpedoes soon became a serious threat to capital ships, i.e. the larger ships of the fleet in later years. Since the torpedoes caused the greatest damage when they hit their targets underwater and since it was impractical to make extensive use of armor for the protection of the 'soft underbellies' of these ships, naval designers modified their hulls by providing double or triple bottoms and highly compartmentalized hulls. An excellent example of this is provided by the hull design of the German battleship Bismarck which, despite being repeatedly hit by torpedoes from destroyers and aircraft during a lengthy engagement in World War II in May 1941, remained afloat because of her excellent watertight integrity produced by her multi-bottom and multi-compartment design.
About the time of the Spanish-American War, the torpedo-boat came into being and was used to great effect against heavier ships. As a defense against these boats, larger torpedo-boat destroyers were developed, the latter finally evolving into the destroyer whose principal weapon for many years was the torpedo it had originally been designed to counter.
During this period all torpedoes were designed for underwater launching and until 1922 even battleships used torpedoes. A torpedo for being launched above the surface was first developed in 1910; it incorporated a horizontal type turbine instead of the earlier vertical type, had a 'hot-running' engine, a speed of 35 knots and a range of 2,000 yards. Later there was some improvement in torpedo operation but torpedo design virtually remained unchanged until the end of World War I.
During World War I, Germany sank 1,381 Allied merchant ships by using torpedoes alone, and during World War II, German naval designers developed the acoustic torpedo which virtually brought the Allies to the brink of defeat. It played havoc with Allied shipping during the Battle of the Atlantic but the downslide was stopped in the nick of time by developing a device that provided fairly effective defense against the acoustic aspect of these torpedoes.
After the target had been identified and its direction and range established, the acoustic torpedo was launched in the general direction of the target. After traversing some distance, the acoustic device of the torpedo would pick up the noise made by the target's propellers and would then 'home' on to the source of the noise. This torpedo posed the greatest danger to large conveys as it could be launched in the general direction of the target without having to solve what is known as the fire control problem and leave the rest to the torpedo itself. Another advantage of the acoustic torpedo was that it did not require high speed to intercept its target; so long as its speed was higher than that of the target, it homed on to it though it had to run for a little longer period. This led to the development of the torpedo which could zigzag, popularly referred to as the Wobbly Willie, or follow a spiral track, as did the Curley Charlie, during its course until it picked up the target and homed on to it.
The acoustic torpedo played havoc with Allied shipping during the Battle of the Atlantic. The only defense against this torpedo was a noisemaker which was developed during the war. Being louder than the target's propellers the noisemaker diverted the torpedoes to erratic tracks until they lost contact or ran down after exhausting their fuel.
Most of the torpedoes used until the 1950s came in two sizes - those fired by submarines and destroyers were 21-inches in. diameter and 21 feet long and those fired by torpedo planes and, during the later part of World War II, by patrol-torpedo boats (P.T. boats) were 225 inches in diameter and 13.5 feet in length. The cylindrical steel flask containing compressed air at a pressure of 3,000 pounds per square inch was fastened to a pointed nose-piece containing several kilograms of explosives. An exploder mechanism, which was set to detonate when it came into contact with any object, was inserted in the warhead before the torpedo was fired.
During actual operation, in order to prevent discovery by the enemy of an unsuccessful attempt, live torpedoes were designed to sink at the end of their run if they did not explode. Japanese torpedoes were, however, designed to explode at the end of their run if they failed to hit a target. A few years earlier, German torpedoes were designed to remain afloat at the end of the run so that they could be used as mines, i.e., there could be some chance of the torpedo being struck by another ship.
The electric torpedo, which was powered by batteries and was cheaper and easier to produce, was slower than the steam torpedo and of less range, but did not produce any air bubbles and hence did not produce any wake. While the steam torpedo had a speed of 45 knots and a range of 4,500 yards which increased to 15,000 yards if the speed was reduced to 30 knots, the electric torpedo had a range of 4,000 yards at 30 knots.
Until the early 1950s the mobile platforms used for launching torpedoes included destroyers, submarines, patrol-boats and aircraft. Destroyers and P.T. boats launched torpedoes by ejecting them from tubes mounted on their decks with a charge of powder, the latter also carrying aircraft torpedoes which were merely dropped over the side. These torpedoes were used by the P.T. boats to launch attacks on all types of vessels including battleships.
Torpedoes were launched by submarines from tubes fitted in their bows and sterns with a charge of compressed air. Cruisers were initially fitted with torpedo tubes but discontinued using them after 1936; battleships never used them mainly because their gun range far exceeded the torpedo range and at torpedo range they presented very large targets to the enemy vessels.
The greatest torpedo threat during World War II came from the torpedo planes because the attack could come from a number of directions at once and the warning was very short because of the high speed of the planes. Because of this advantage and better cost effectiveness of torpedo planes over destroyers, World War II saw increasing employment of aerial torpedo attacks.
During World War II submarine warfare was almost exclusively fought with torpedoes; and the effectiveness of the torpedo against surface vessels can be gauged from the fact that out of a total of 10,583,755 tons of Japanese naval and merchant shipping sunk by the Allied forces during World War II, 5,320, 094 tons, i.e., over 50 per cent was accounted for by torpedoes fired from United States' submarines alone.
Other Important Features
As is well-known, the eye of the submarine is the periscope which was invented and developed solely for the purpose of providing a means to view the surface or sky without detection by surface vessels or aircraft. The earlier designers of submarines didn't provide for any viewing device for submarines when they were in a submerged or semi-submerged state, as a result of which they had to grope their way blindly after diving. But the need for a suitable viewing device was soon realized and in 1854 a Frenchman, E.M. Marie-Davy, designed a submarine sight tube containing two mirrors, one above the other, held at the angle of 45 degree and facing in opposite directions. These did provide some degree of sight to the submerged vessels but were rather limited in performance and were hence substituted in 1872 with prisms. The credit for inventing the original periscope goes to Thomas H. Doughty, who developed the basic form during the American Civil War.
The first American submarine to use an internal combustion engine was fitted with 45 horse-power, two-cylinder, four-stroke gasoline engines while the British preferred gasoline engines fitted with 12 or 16 cylinders. The inherent hazards of these engines were soon realized, for stowage was a constant problem and handling of fuel was extremely dangerous. Also, internal explosions were frequent and many of the engines gave off considerable carbon monoxide fumes, creating a menace to personnel.
M.A.N. (Maschinenfabrik Augsberg-Nwinberg A.G.) of Germany had developed a four-stroke diesel engine, capable of producing 1,090 horse power but all these engines developed structural weaknesses in the crankcase. Until 1930 the engines used in most submarines of all the larger naval powers with the exception of Great Britain were four-stroke diesels.
With the development, however, of fleet type submarines, the need for more powerful engines became apparent and eventually a 16-cylinder single-acting engine was developed as well as a 9-cylinder double-acting engine. The fact that submarines are both surface and sub-surface vessels places definite restrictions on size, hull design and shape. The total weight of the submarine is also a factor having considerable bearing on underwater operations. In the first engine powered submarine, the engines were mechanically connected directly to the propeller shafting. It, however, became apparent after testing various types and designs, that the diesel-electric drive was the best. In this type, the engines were connected only to the generators, which in turn supplied power to the main motors driving the propeller shafting. Another function of the generators was charging the storage batteries.
Today's fleet type submarines are generally powered by four main propulsion diesel engines, each capable of driving a generator producing around 2,000 horse-power which in turn drives a slow-speed motor or charges a bank of batteries. An auxiliary engine is also available for driving the generators.
As is known, the conventional submarine does not use the diesels or generators while submerged, and power for the motors is supplied by two sets of storage batteries, which are charged by the auxiliary and main generators during surface operations. The two main storage batteries consist of two groups of over 100 cells each, each one of these cells weighing several quintals.
During the latter part of World War II, the Germans adopted a radical change in submarine design known as the 'schnorkel' -an invention made by the Dutch in 1936 for replenishing air supply of the crew of their submarines. The spelling was simplified by the Americans to 'snorkel' and further abbreviated by the British to 'snort'. The Germans were forced to develop the new device because of the rapid strides already made in the development of improved sonar (underwater sound-aided detecting and ranging equipment) and radar, used by the Allied aircraft and surface vessels against German vessels.
The schnorkel was originally a breathing tube which was raised while the submarine was at periscope depth. When it was raised in position, air for the crew was obtained from the surface. In 1944 the Germans equipped their submarines with double-tube schnorkels, one for Jetting in air for the submarine's diesel engines and crew and the other as an exhaust for diesel fumes, carbon dioxide and other pollutants. The intake tube projected by a foot or so above the sea surface while the exhaust gases were discharged into the sea. This considerably reduced the visible portion of the submarines and also consumption of electric power, since the submarine could cruise almost totally submerged on its engines and conserve its battery power for attacks and evasive measures.
The schnorkel had only one drawback. While by itself it was too small to be spotted from a distance or from the air ii left a distinct wake which could be visually picked up from an antisubmarine ship or aircraft in calm weather. It could also be detected by the radar fitted on ships or aircraft. Darkness or fog could not provide any camouflage any more.
The United States Navy developed an improved schnorkel and also the 'guppy' submarine at the end of World War II. The guppy (greater underwater propulsion power) had the same type of hull as that used for the fleet submarine of World War II fame, was 306 feet long and displaced about 1,800 tons. The only change in the hull was in the superstructure which was radically changed by reducing the surface and streamlining every protruding object. The life lines and all guns were removed, the bitts (posts) to which ropes were secured were made retractable and the periscope shears (supports) enclosed in a streamlined metal fairing. All topside armament and equipment were
RUN SILENT RUN DEEP
The Evolution of the Submarine
The submarine came into its own during World War I, it’s devastating lethality and near-invincibility reinforced during and after World War II, and its nuclear propulsion and teeth giving it virtually limitless range and calamitous destructive power during the post-World War II years. However, it made a fairly late entry into India's naval fleet, possibly because the submarine was earlier considered an 'offensive' weapon platform and hence could not have a place in the arsenal of a country that had pledged to abide by the principles of peace.
Since the capability to operate in the third element - me subsurface -has now been added to the Indian Navy's repertoire, it is essential that the evolution of the submarine from its tentative conceptual state in the 16tR: century to its present day status of being the prime dealer of destruction at sea, as well as the significant role it played in shaping the ends of the two World Wars, be studied in detail before apprising oneself of the process of establishment of the submarine arm in the Indian Navy. This chapter provides a brief resume of such developments around the globe.
While addressing the men of the Royal Navy's Submarine Service during World War II, Winston Churchill had said; 'Of all the branches of men in the Forces, there is none that shows more devotion and faces greater perils than the submariner . . . great deeds are done in the air and on the land, nevertheless nothing surpasses your exploits.' Indeed, nothing can transcend the tour de force that the submarine has displayed and the impact of the revolutionary changes in the concept; both strategic arid tactical, of the war at sea brought about by its invention. Besides, its use for opera-ions against a wide variety of targets during the last century have been far greater than that of the supersession of the oared galley by the sailing galleon, the sailing ship of the line by the steam ironclad, the battleship by the carrier-borne and shore-based maritime aircraft, and the diesel-electric propulsion systems of submarines, by the nuclear power plant.
Adoption of new techniques, technology, strategy or tactics, weaponry and weapon platforms generally require a fairly long lead time because their potential and advantages over the existing techniques, tactics, etc, have to be convincingly established before they are introduced in any Service. Oared galleys continued to be constructed for England's Navy for several years after the defeat of the Spanish Armada; even thirty years after the first battleship had been fitted with engines, steam ironclads continued to be equipped with sails, and when World War II was coming to an end in 1945, the British Admiralty was still working on a new design for a 16-inch gun turret. For similar reasons, despite the developments in submarine technology in Europe and America concurrently with those in Great Britain, the Royal Navy woke up to the danger posed by submarines only after the outbreak of World War I when the armored cruisers, Cressy, Hoque and Aboukir, were sunk by one small German U-boat as a result of which the Grand Fleet's method of cruising the sea had to be drastically altered. J& fact, until the time they learnt their lessons the hard way, the British had been doing their best to discourage the development of submarines because they still believed that they, with their huge surface navy, had nothing to gain and much to lose by their development. As a result of the adoption of this attitude, the design of the first submarine for the Royal Navy had to be purchased from America for construction in Britain and, what is even more surprising, this class of submarines were built not to supplement the British war effort but only to enable the British designers to find an antidote to them! It is significant to note that until October 1, 1901, when the Royal Navy's Submarine Service came into being with the launching of Submarine No, 1(129 tons), the popular view in Britain, which has a seafaring history spanning several millennia, was that submarines were 'underhand, unfair and damned un-English'.
This is of course not surprising as there is no profession so wedded to tradition as the military. During World War I the machine gun had been scorned as the 'much-overrated weapon'; the tank was thought of as a 'toy'; Marshal Joffre had refused to have a telephone installed in his office; poison gas was reluctantly adopted by the British after its use by the Germans was classified as a mere 'accessory'; the trench mortar was projected twice by the British War Office and was finally accepted after a cabinet minister secured the funds for it from an Indian maharaja; British subalterns got 'their swords sharpened before crossing to France; and as late as 1918 ‘Pershing had cluttered up his supply lines with mountains of fodder for useless horses, still dreaming of Custer and Sheridan and the glint of Virginia moonlight on the shirting saddles of Stuart's cavalry.’
Early History
There are occasional references in ancient history to the attempts made by man to seek stealth and surprise by operating from submerged or semi- submerged vessels during wars at sea. The very early protagonists of the submarine were not so much inspired by the desire to descend below the surface of the sea to explore the depths of the sea as to devise a method of rendering a warship invisible to the enemy so that it could carry out surreptitious attacks and escape at will.
The earliest reference to attempts made at waging underwater warfare is found in the writings of Aristotle who recorded that Alexander the Great used diving bells to enable his men to descend below the surface of the sea during the siege of Tyre in 332 B.C. He also ordered his divers to impede or destroy the defensive barriers still in use and known as boom defenses) the city was likely to build to prevent the movement of submerged vessels. In fact, according to legend, Alexander himself made a descent into the sea in a device which kept its occupants dry and admitted light-However it is believed that nearly a century earlier than Alexander's experiments; the Athenians had used divers to clear the entrance to the Syracuse harbour during its siege from 415 to 413 B.C.
Over the following two millennia the potential and the tactical advantages of operating below the surface of the sea continued to be appreciated by many military thinkers and several attempts were made during this period to develop an underwater platform that could be used against enemy shipping and war vessels far more effectively than surface ships, both for offensive and defensive operations. In the 16th century, during the Renaissance, Leonardo da Vinci, is said to have designed a vessel which could dive, remain submerged for some time and surface unaided end could surreptitiously plant bombs or mines on enemy vessels, but the design of this submarine was kept secret because da Vinci he felt that man would misuse it- 'He knew a method of remaining a long time underwater, but he refused to tell of it because of the "evil nature of man”.
The Submersible Takes Shape
Experiments in diving and moving underwater continued but the first recorded mention of a submarine design conforming to the basic principles of submersion is found in the writings of a British naval officer, William Bourne, who published a detailed design of a 'boat that may go under the water' in 1578. The vessel was a completely enclosed boat which could be submerged by reducing its volume by contracting the sides through the use of hand vices, which could bring the boat back to the surface by increasing the volume. This vessel could also move underwater by using watertight oars. This realistic design provided for both submersibility and propulsion underwater but was never built.
Twenty-seven years later, in 1605, using a design similar to Bourne's, Magnus Pegelius constructed a submersible boat but due to the viscosity and adhesive properties of underwater mud the craft never surfaced after diving.
In 1620, a Dutch physician, Cornelius van Drebel, built a submarine and successfully conducted trials in the Thames River, making the craft cruise repeatedly on the surface, dive, maneuver underwater and then surface for several hours at a stretch. He later built two more craft, embodying the same principles, but larger in size. Van Drebel’s craft had an outer hull made of greased leather stretched over a wooden framework. Propulsion was provided, both on the surface and while submerged, by oars which extended through the sides and which were sealed and rendered watertight with tight-fitting leather flaps which allowed free transverse movement while anchoring the oars to the hull. The underwater endurance of the submarine crew was sought to be enhanced by using compressed oxygen to 'restore to the troubled air such portion of vital parts as would make it again, for a good while, fit for respiration/After repeated trials in the Thames river had established the capabilities of the new 'boat' in travelling on the surface and maneuvering underwater at depths of 12 to 15 feet, King James I is reported to have taken a trip in one of the larger models to demonstrate its safety. But despite the conclusive proof of the designers having evolved a powerful two-dimension weapon platform, the novel features of the submarine failed to arouse the interest of the British Navy.
The wars in the 17th century in Europe, however, Jed to a proliferation of submarine designs some of which were the work of men from professions other than those associated with the navy or seafaring; in fact some of the designers were men of peace, i.e., priests and monks! One such designer was Oliver Cromwell's brother-in-law, John Wilkins, Bishop of London. His device for jettisoning gash through an underwater lock while remaining submerged led to the development of underwater lavatories in the latter-day submarines which obviated the need for the submarine to surface repeatedly. He also wrote on future naval developments and centuries later many of his predictions turned out to be true; such as his prediction of journeys by submarines under the Polar ice-cap, an idea which was dismissed as science fantasy In the 17th century.
By the middle of the 17th century, many naval architects had conceptualized and experimented with possible submersible weapon platforms. In 1653, a Frenchman, de Son, designed and built a 72-foot submarine 'that doeth undertake in one day to sink 100 ships' but his submarine never sailed, as its prime mover, a clockwork device, was not powerful enough to propel it on the surface or underwater.
The earlier decades of the 18th century saw numerous 'underwater boats' built, the British designers alone having patented no fewer than fourteen types by 1727. The concept of using a ballast tank for submerging and diving was first visualized by an inventor who described his design in the Gentleman's Magazine ml747. The hull of his craft was equipped with a bank of goatskins which would be filled with water to make the vessel submerge and a 'twisting rod' would be used to force the water out of the goatskins which would provide positive buoyancy and bring the Vessel back to the surface. This craft, however, was never built. At this time the mechanical and physical principles involved in diving and surfacing were yet to be fully understood and hence many of the ideas put forward turned out to be impractical, fanciful or, in some cases, even grotesque. Besides the lack of understanding of the principles, the general impression at this time was that it would be impossible to navigate a craft underwater and even if it became possible, its tactical advantages in naval warfare would be minimal.
The First Submarine, Bushnell's Turtle
However, developments of a submersible craft with weapon delivery capability received a shot in the arm in 1776 when the first submarine that could dive, surface, cruise -both on the surface and underwater-and plant explosives on enemy vessels while remaining submerged, made a dramatic appearance during the American War of Independence. David Bushnell, an American farmer's son, had developed the technique of exploding gunpowder underwater and had followed it up with the invention of the first one-man submersible that was to be used as a weapon platform, the Turtle. Shaped like a wooden beer-barrel, it was powered by a hand-operated screw propeller which could move it at a speed of three knots. It could stay submerged for 30 minutes during which it had to approach its target underwater, plant an explosive on its hull and get away.
It was on September 6, 1776, 29 years before the Battle of Trafalgar, that Ezra Lee, a sergeant in the American Revolutionary Army and the first submariner to launch an underwater operation against enemy vessels, undertook to scuttle Eagle, the Flagship of the British Fleet which was blockading New York Harbour, by planting a powerful explosive on its hull. He set off on his historic mission all by himself on board the Turtle and, operating the handle of the screw-propeller hard for several hours, reached the Eagle and dived. The Turtle then got under the hull of the Flagship and Lee tried to bore a screw device into the Eagle's hull for securing the explosive device to it. Later, a pre-set clockwork mechanism would trigger the explosive device. Unfortunately for Lee, the wooden hull of the Flagship had a sheathing of copper for reinforcement and prevention of the formation of any marine growth. Despite repeated attempts, Lee failed to penetrate the hull. He persisted with his efforts to plant the device, but soon the effects of carbon dioxide poisoning overwhelmed him. He then withdrew, surfaced and set course for shore but was spotted and pursued by a British patrol-beat. Lee jettisoned the explosive cargo and it went off, almost blowing the patrol-boat out of the water.
The Commander of the British Fleet soon realised that his Flagship had had a narrow escape and ordered the blockading ships of his fleet to withdraw to the outer harbour, where they were comparatively safer, but the effectiveness of the blockade was considerably reduced. Thus while the first sub-surface attack in. the history of submarines had proved to be abortive, it brought home one lesson which holds good even today- that the mere presence of a submarine lurking below the surface can upset the plans of a tactical commander over a large area far more than the sinking of a ship. In other words, the fear of the unknown and the element of surprise area greater deterrent at sea than an actual attack. Submarine warfare thus became a reality, even though the first ever submarine attack had failed to cause any physical damage.
Fulton's Nautilus
Robert Fulton, the American inventor who was the first to propel a boat by steam in 1803, and the first to build a steam warship, the Fulton, in 1815, is better remembered for having constructed a three-man submarine boat, the Nautilus, in 1795. Incorporating nearly all the main features of a modem submarine and shaped like one, the Nautilus, which was built of steel and shaped like an elongated oval, was powered by sails on the surface and by a hand-driven screw-propeller under water. Since the periscope was yet to be invented, a primitive form or a conning tower, equipped with a watertight port hole was provided and was used for observation and maneuvering the craft underwater. It was also equipped with ballast tanks for diving and surfacing, as modern submarines are, and had a submerged endurance of three hours for four men to breathe and two candles to bum! Like the Turtle, it had a device which could attach explosives to the hull of a ship while remaining underwater. During its trials at Brest, the Nautilus had also proved its capabilities by sinking an old schooner.
Since the war was over, the American naval authorities showed little interest in Fulton's submarine design, compelling him to build the Nautilus at Paris. He offered it to the authorities to deploy it off the French coast against British warships but it failed to sink or damage any ship.
Disappointed, Fulton then approached the British authorities and demonstrated the capability of his submarine craft by sinking a ship in 1804. The Prime Minister, William Pitt, was so impressed by the submarines performance that he asked the Admiralty to acquire the craft. His request was, however, dismissed by the First Sea Lord (then Earl St. Vincent) with the rather intemperate remark, 'Pitt was the greatest fool that ever existed to encourage a mode of war which those who command the sea do not want and, if successful, will deprive them of it/
For about 60 years after the disappearance of the Nautilus, inventors continued to test various designs of small, hand-propelled submersibles with a crew of six to eight men. None of these was, however, an improvement on Fulton's craft, and hence no progress towards further development of submersibles was discernible. However, during the American Civil War the next nautical milestone in submarine development was recorded, with the sinking of a warship by a submarine, when a Federal corvette, the Housatonic, which v/as blockading Charleston harbour, was scuttled by the Confederate submersible David (according to the Encyclopedia Britannica, the name of the submersible was Hartley) in 1864. An explosive pack, suspended ahead of the bow of the David from a bowsprit, accomplished the feat when the submersible rammed the corvette. However, when the Housatonic was salvaged, the mangled wreck of the David was found sandwiched between the corvette's hull and the seabed. Because of the submersible's proximity to the Housatonic, the explosive had proved to be as much of a danger to the attacker as to its target. The Housatonic thus had the dubious honour of being the first surface vessel to be sunk by a submarine (and the first surface vessel to have crushed a submarine in an unintended Kamikaze attack).
Progress in submarine development continued to be bedeviled by the absence of a suitable propulsion device to enable the submarine to operate underwater for long periods, and an explosive which, rather than being planted, could be launched or fired by the submarine from a safe distance.
Steam and Electric Propulsion
Steam engines, though bulky and messy, were tried for some time for the propulsion of submersibles and in 1880, George Garret, an English clergyman, built a submarine which was propelled by two propellers driven by steam from a coal-fired boiler, which featured a retractable smokestack for ventilation. About this time, a Swedish gun designer, Norden felt, also constructed a submarine powered by steam. This submarine was capable of submerging to a depth of 50 feet, had an underwater endurance of 20 miles and was the first submersible to be fitted with a practical torpedo tube. The novelty of the new weapon-launching device appealed to the Turks and Russians, who acquired some of these craft but, because of their limitations, could not achieve anything worthwhile.
Experiments with the still new form of energy, electricity, had in the mean time proved successful, and storage batteries with several hours of endurance had been developed for the propulsion of submarines with electric motors. In 1886 two Englishmen, Campbell and Ash, developed an all-electric submarine which was powered by two 50-horse-power motors operated from a 100-cell storage battery. It was capable of maintaining a surface speed of six knots but the storage capacity of its battery being very low, its effective range was limited to only 80 miles.
The endurance of the storage battery for submarines was considerably improved by a Frenchman, Claude Gombat who, between 1888 and 1890, built some small battery-powered submarines which were acquired and used by the French Navy for about 10 years. These submarines were about 160 feet long, had a maximum speed of 13.5 knots and an effective range of 200 miles.
The 'Holland Type' Submarine -Ballast Tanks and Hydroplanes
Meanwhile John P. Holland of New Jersey, an ex-Irish school teacher who had migrated to the USA and who was to virtually become the creator of the Royal Navy's submarine service, had launched his first submersible in 1875. In 1882 he constructed the Fenian Ram which was tested on the Hudson River, and which was propelled by gasoline engines en the surface and electric motors underwater. These submersibles had several features which had to be discarded later, but some of Holland's innovations, perfected during the following years, have been incorporated in the latter-day submarine design. Of these, the most important are the use of ballast tanks for submerging and surfacing, and horizontal rudders or hydroplanes for maneuvering the craft in the vertical plane for depth control.
For some years Holland and Nordenfelt were vying with each other for an order from the United States Government for building a submarine and it finally went to the former in 1895. The vessel that was designed, the Plunger, was to be powered by a coal-fired steam engine on the surface, and battery-operated twin motors under water. Numerous designing defects came to light during construction and the craft was eventually abandoned. A new model, Holland's ninth, was built in his shipyard and delivered to the United States Government in 1900 and was used as the basic design for all the submarines that were built subsequently. This submarine, which was launched in 1897 and which was tested for three years before delivery, was named the Holland.
A contemporary of Holland, Max Lanbeuf of France, also built a submarine, Nerval, which was similar in construction to Holland's submarines and it was also powered by a coal-fired steam engine but, instead of tanks, it used the space enclosed in its double hull for ballast.
Internal Combustion Engine
The submarines of Holland and Lanbeuf were the prototypes for submarines built for several decades thereafter and they had almost all the essential features of modern day conventional submarine -ballast tanks, internal combustion engines for surface propulsion at nine knots and for charging batteries whilst on the surface and electric motors for underwater propulsion at seven knots; Us effective operational range was an impressive 1,000 miles. However, the internal combustion engines used at that time were gasoline engines which were a fire hazard because they gave off highly noxious and inflammable gasoline fumes, and, later were replaced by diesel engines developed by the German engineer, Rudolph Diesel, during the last decade of the 19th century.
Another submarine designer, Simon Lake, had built a submarine, the Argonaut Junior, in 1894 which was primarily meant for use in such peacetime operations as the exploration and exploitation of the living and mineral wealth below the surface of the sea and under the seabed, and for commercial salvage operations. The submersible was made of two layers of yellow pine with a sheet of canvas between them to render it impervious to water. This submarine could move about on the seabed and had an air-lock device which permitted its crew, using diving helmets, to emerge from the submarine and explore the surroundings.
In 1897, Lake built his second submarine, the Argonaut, which was powered by a 30-horse-power gasoline engine, had a 36-foot cigar-shaped hull and could submerge to the bed of a river or the bottom of a lake and move along the bed on three wheels which could be retracted and housed in the keel when the submersible was navigated. A year later, i.e., in November 1898, the Argonaut had the honour of being the first submarine to cross the Atlantic when she sailed from Norfolk and, despite heavy storms encountered on the way, reached New York.
Another submarine, the Protector, was built by Lake in 1906 and sold to Russia. After it was tested and accepted in Russia, he built several more, submersibles for the Russian Government.
The French Submarine -The Gustav Zede
Claude Gombat, a Frenchman, built some small but effective submarines between 1888 and 1890. One of these, the Gustav Zede, which was in service with the French Navy for over ten years, had a hull 160 feet long, was powered by storage batteries and had a range of 200 miles at a cruising speed of six knots and a maximum speed of 13.5 knots.
In 1901, this submarine, while taking part in exercises, staged a mock attack on the French Mediterranean Fleet after travelling 160 miles under her own power. While remaining totally undetected, the submarine hit the battleship Charles Martel, the pride of the French Navy, with a dummy torpedo. The successful 'sinking' of a fully protected battleship by a tiny submarine which could approach its target, deliver a lethal blow and escape without being detected, was a watershed in the history of submarines and was an object lesson to the naval planners of all major countries, in the changes that were going to be wrought into the future shape of sea power.
By the end of the 19th century, only six navies in the world had acquired a total of 10 submarines and eleven more were being built. Leading the submarine-owning countries was France, which had a total of 14, built or building, followed way behind by the United States which had only two, one of these two being of the Holland-type which was at that time reckoned to be the best design in the world. The other countries which had acquired submarines were Italy, Portugal, Spain and Turkey which had one craft each. Britain, which had one of the mightiest navies at that time, was yet to acquire one because of active and continued discouragement from the British Admiralty.
The 1901 success of the French submarine, Gustav Zede, however, came as a rude shock and an eye-opener to the mandarins of the Admiralty, and so it overruled the policy of the First Sea Lord, Earl St. Vincent, and promptly ordered five submarines of the Holland type of the US Navy -not for using them against enemy warships or for coastal defense- but for intensive research into antisubmarine measures! The first submarine built for the Royal Navy, Submarine No. 1 (with only one torpedo cube) was thus launched on October 2, 1901 and the submarine service of the Royal Navy was born.
Submarines for the British Navy -Acute Submarine-Phobia
The policy of active discouragement against submarine development had prevailed in the British Admiralty for about a century. Hence there had been practically no research in submarine development in England during the 19th century. As a consequence the design for the first submarine for the Royal Navy had to be acquired from the USA. In trying to perpetuate this bias, even as this submarine was being commissioned, the Admiralty had decided to curtail the formalities associated with the commissioning of the new vessel to the minimum. To quote an official notice reproduced in the journal Naval and Military Record of October 3, 1901, the day after the launching: It is understood that no ceremony will take place at the forthcoming launch of the first British submarine at Barrow-in-Furness. The Admiralty regard these boats as wholly in the nature of an experiment and, like all other experiments conducted from time to time, this one will be carried out with all privacy.
Despite the official stance against the development of the underwater craft, shipbuilders in Britain had actually started building submarines as early as in 1885 - full sixteen years before the construction of the first submarine for the Royal Navy. In that year work had commenced on me construction of an experimental submarine at the Barrow- in-Furness shipyard. This submarine, which had a 100-foot hull, had been built in sections by 1886, sold to the Turkish Government, shipped out to that country, and assembled there for the Turkish Navy. Soon, another submarine, 123 feet long, was built at Barrow and sold to the Imperial Russian Navy. It is interesting to note that 'underhand, unfair and un-English' warfare wasn't acceptable to Britain but others could indulge in it so long as it yielded lucre for her!
After building five Holland-type submarines, Britain built the first A-class submarine (with one torpedo tube) in 1902, B-class (with two torpedo tubes) in 1905, C-class (with two torpedo tubes) in 1906, D-class (with three torpedo tubes, one tube being in the stern, and a 12-pounder gun) in 1908, and E-class (with five torpedo tubes, and one six-pounder or four-inch gun) in 1913. The B-class was the first to be fitted with surface weapons, and the D-class was the first to be equipped with a diesel engine and stern torpedo tube -all earlier classes having used gasoline engines for propulsion, and being fitted with forward torpedo tubes.
The submarine-phobia and surface-vessel mania of the British Admiralty, even after submarines had begun to the built for the Royal Navy, is evident from what Captain Hugh Oliphant, who was the Commanding Officer of Dolphin, the Royal Navy's submarine training establishment, and Captain, First Submarine Squadron some years ago, said about the prevailing ambience at that time: 'One serving British Admiral was at that moment publicly demanding that submarine crews (captured) in war should be treated as pirates and hung; the Director of Naval Construction was warning non-expendable senior officers "never to go below water", and the Engineer-in-Chief considered that the running of a petrol engine in a confined space was so dangerous that the first submarine moorings in Portsmouth were among the remote quarantine and powder hulks’. The first submarine 'depot ship' and training school was thus given the not inappropriate name of Hazard’.
By now, even in the Royal Navy, some of the senior officers had realized the potential of the submarine and were quite vociferous in demanding a change in the naval policy. In 1904, Admiral Lord Jacky Fisher wrote prophetically:
It is astounding to me, perfectly astounding, how the very best amongst us absolutely fail to realize the vast impending revolution in naval warfare and naval strategy that the submarine will accomplish!'
Here, just to take a simple instance, with the battleship Empress of India, engaged in maneuvers and knowing the proximity of submarines, so self-confident of safety and so oblivious of the possibilities of modern warfare.. . and suddenly they see a Whitehead torpedo miss her stern by a few feet!
And how fired? From a submarine of the 'pre-Adamite' period; small, slow, badly fitted, with no periscope at all.
. . . . I have not disguised my opinion in season and out of season as to the essential, imperative, immediate, vital pressing, urgent (I can't think of any more adjectives) necessity for more submarines at once, at the very least 25 in addition to those now ordered and building and 100 more as soon as practical, or we shall be caught with our breeches down....
The turn of the century was thus a watershed in the history of submarines, for the fundamental principles of the construction and operation of submersibles had taken, concrete shape and been demonstrated to the world by this time. It continues to be valid even today. Internal combustion engines, both gasoline and diesel, had proved to be the most efficient and practical power plants; electric propulsion, as an alternative or in tandem with diesel or gasoline engines, had proved a success; the invention of the periscope had increased the feasibility of underwater navigation and improved the potential of the submarine for surveillance and for carrying out attacks while remaining submerged; and the torpedo, the primary weapon of the submarine, had been perfected and had proved its deadly capability. The manually propelled and operated one-man submersibles had been replaced by the larger and more versatile, long-range and long-endurance submarine. These would soon become a major component of naval strategy, both for offence and defense. Anew chapter had begun in the history of naval warfare.
Special Features of Submarines Developed
Some of the features peculiar to these submarines were the all-welded hull, the periscope, the schnorkel or the snort, the diesel-electric propulsion system and the revolutionary weapon - the torpedo.
Below the superstructure deck was the hull which had to withstand the tremendous pressure of sea water while submerged, and to maintain its watertight integrity under varying pressure conditions. The shape of the vessel had evolved from Bushnell's spherical Turtle to the cylindrical Holland genre over a period of 125 years, the latter being constructed on the basis of the fabrication of a series of watertight containers by means of watertight joints. In the double-hull type of submarines, the pressure hull was inside the outer hull and between these hulls were the water and fuel oil tanks.
The space between the non watertight superstructure deck and the pressure hull was used as locker space for stowing anchor gear, lines, ammunition for the submarine guns, boats and other equipment that did not get damaged by immersion in Water. Extending upwards through the superstructure amidships was a watertight tower known as the conning tower, the top of which was the bridge from where the vessel was controlled when on the surface. But when submerged, it was controlled from the conning tower or from a compartment directly below it, known as the control room. For making observations while totally submerged, periscopes extending above the bridge were operated from the conning tower.
Evolution of the Torpedo
The submarine is essentially a torpedo vessel, launching Its torpedoes while surfaced or submerged, and hence it has basically evolved over the years as a torpedo-launching platform, though today its weapon outfit includes missiles. The torpedo too has been developed into a highly complicated underwater projectile with a heavy explosive charge. It is detonated by an exploding mechanism when in contact with, or in proximity to, the hulls of target vessels. Today, high-power engines drive it at high speed and sophisticated instruments control its course. Torpedoes are fired by, or launched by, surface vessels, aircraft or submarines. Its capability of being launched, approaching the target and striking with little or no warning makes it particularly useful to submarines, which can frequently carry out an attack and escape without being detected.
The word torpedo is derived from the word Torpedinidae, the family name for the fish called electric rays. These fish and electric eels have been referred to as torpedoes. The term torpedo was first applied to an explosive device around 1800 and, in its various experimental forms, this name was used for the next 65 years or so for a type of floating mine.
The first to use an explosive device of this category was David Bushnell in 1776. His was a simple type of floating mine with a clockwork mechanism which was designed tc be secured to the bottom of an enemy vessel with the help of a screw driven into the latter's hull, and to go off after the pre-set interval. As described earlier, no damage was caused to the target, the British warship Eagle, as the submersible, Turtle failed to secure the explosive device to the ship's hull.
Robert Fulton, the American genius whose talents had been recognized not at home but in France and England, used 'a catamaran torpedo' developed by him in an attack on the French Fleet at Boulogne on October 2,1804. Twelve of these devices were turned loose against the French ships, creating great excitement but causing no damage as they exploded short of their intended targets.
During the American Civil War, various kinds of torpedoes were used by the Union and Confederate forces. Some of these were simple beer kegs filled with gunpowder whose use was responsible for the well-known outburst from Admiral David Farragut, 'Damn the torpedoes... Go ahead!' At the other extreme were the gigantic electric torpedoes carrying over 90 kilograms of explosives each, one of which was used to blow the Federal gunboat Commodore Jones to smithereens.
It was an English engineer, Robert Whitehead, who, in 1868, perfected the first practical self-propelled torpedo, the forerunner of the modern torpedo. The Whitehead torpedo used all the basic principles that are used even today, such as hydrostatic depth control lateral control, and an engine which powered two contra-rotating propellers; the source of power for the 'cold-running' torpedo was compressed air contained in a metal flask which produced a speed of seven knots over a range of 700 yards. During the last decade of the 19th century, the US Navy used this torpedo, its speed increased to 27 knots though its range had been extended only by 300 yards.
The first 'hot-running' version, the Bliss-Levitt torpedo, was designed by an American, E.W. Bliss, in 1904 and featured a combustion chamber burning alcohol, preheated from the flask in which the pressure was increased. The combination of higher pressure and preheating increased the range to 4,000 yards.
Meanwhile, the introduction of torpedoes had radically changed naval warfare. In 1877, a superior Turkish naval formation was forced to keep clear of the Russians off Odessa because the latter had equipped its ships with torpedoes. With their rabidly increasing speed, range and hitting power, torpedoes soon became a serious threat to capital ships, i.e. the larger ships of the fleet in later years. Since the torpedoes caused the greatest damage when they hit their targets underwater and since it was impractical to make extensive use of armor for the protection of the 'soft underbellies' of these ships, naval designers modified their hulls by providing double or triple bottoms and highly compartmentalized hulls. An excellent example of this is provided by the hull design of the German battleship Bismarck which, despite being repeatedly hit by torpedoes from destroyers and aircraft during a lengthy engagement in World War II in May 1941, remained afloat because of her excellent watertight integrity produced by her multi-bottom and multi-compartment design.
About the time of the Spanish-American War, the torpedo-boat came into being and was used to great effect against heavier ships. As a defense against these boats, larger torpedo-boat destroyers were developed, the latter finally evolving into the destroyer whose principal weapon for many years was the torpedo it had originally been designed to counter.
During this period all torpedoes were designed for underwater launching and until 1922 even battleships used torpedoes. A torpedo for being launched above the surface was first developed in 1910; it incorporated a horizontal type turbine instead of the earlier vertical type, had a 'hot-running' engine, a speed of 35 knots and a range of 2,000 yards. Later there was some improvement in torpedo operation but torpedo design virtually remained unchanged until the end of World War I.
During World War I, Germany sank 1,381 Allied merchant ships by using torpedoes alone, and during World War II, German naval designers developed the acoustic torpedo which virtually brought the Allies to the brink of defeat. It played havoc with Allied shipping during the Battle of the Atlantic but the downslide was stopped in the nick of time by developing a device that provided fairly effective defense against the acoustic aspect of these torpedoes.
After the target had been identified and its direction and range established, the acoustic torpedo was launched in the general direction of the target. After traversing some distance, the acoustic device of the torpedo would pick up the noise made by the target's propellers and would then 'home' on to the source of the noise. This torpedo posed the greatest danger to large conveys as it could be launched in the general direction of the target without having to solve what is known as the fire control problem and leave the rest to the torpedo itself. Another advantage of the acoustic torpedo was that it did not require high speed to intercept its target; so long as its speed was higher than that of the target, it homed on to it though it had to run for a little longer period. This led to the development of the torpedo which could zigzag, popularly referred to as the Wobbly Willie, or follow a spiral track, as did the Curley Charlie, during its course until it picked up the target and homed on to it.
The acoustic torpedo played havoc with Allied shipping during the Battle of the Atlantic. The only defense against this torpedo was a noisemaker which was developed during the war. Being louder than the target's propellers the noisemaker diverted the torpedoes to erratic tracks until they lost contact or ran down after exhausting their fuel.
Most of the torpedoes used until the 1950s came in two sizes - those fired by submarines and destroyers were 21-inches in. diameter and 21 feet long and those fired by torpedo planes and, during the later part of World War II, by patrol-torpedo boats (P.T. boats) were 225 inches in diameter and 13.5 feet in length. The cylindrical steel flask containing compressed air at a pressure of 3,000 pounds per square inch was fastened to a pointed nose-piece containing several kilograms of explosives. An exploder mechanism, which was set to detonate when it came into contact with any object, was inserted in the warhead before the torpedo was fired.
During actual operation, in order to prevent discovery by the enemy of an unsuccessful attempt, live torpedoes were designed to sink at the end of their run if they did not explode. Japanese torpedoes were, however, designed to explode at the end of their run if they failed to hit a target. A few years earlier, German torpedoes were designed to remain afloat at the end of the run so that they could be used as mines, i.e., there could be some chance of the torpedo being struck by another ship.
The electric torpedo, which was powered by batteries and was cheaper and easier to produce, was slower than the steam torpedo and of less range, but did not produce any air bubbles and hence did not produce any wake. While the steam torpedo had a speed of 45 knots and a range of 4,500 yards which increased to 15,000 yards if the speed was reduced to 30 knots, the electric torpedo had a range of 4,000 yards at 30 knots.
Until the early 1950s the mobile platforms used for launching torpedoes included destroyers, submarines, patrol-boats and aircraft. Destroyers and P.T. boats launched torpedoes by ejecting them from tubes mounted on their decks with a charge of powder, the latter also carrying aircraft torpedoes which were merely dropped over the side. These torpedoes were used by the P.T. boats to launch attacks on all types of vessels including battleships.
Torpedoes were launched by submarines from tubes fitted in their bows and sterns with a charge of compressed air. Cruisers were initially fitted with torpedo tubes but discontinued using them after 1936; battleships never used them mainly because their gun range far exceeded the torpedo range and at torpedo range they presented very large targets to the enemy vessels.
The greatest torpedo threat during World War II came from the torpedo planes because the attack could come from a number of directions at once and the warning was very short because of the high speed of the planes. Because of this advantage and better cost effectiveness of torpedo planes over destroyers, World War II saw increasing employment of aerial torpedo attacks.
During World War II submarine warfare was almost exclusively fought with torpedoes; and the effectiveness of the torpedo against surface vessels can be gauged from the fact that out of a total of 10,583,755 tons of Japanese naval and merchant shipping sunk by the Allied forces during World War II, 5,320, 094 tons, i.e., over 50 per cent was accounted for by torpedoes fired from United States' submarines alone.
Other Important Features
As is well-known, the eye of the submarine is the periscope which was invented and developed solely for the purpose of providing a means to view the surface or sky without detection by surface vessels or aircraft. The earlier designers of submarines didn't provide for any viewing device for submarines when they were in a submerged or semi-submerged state, as a result of which they had to grope their way blindly after diving. But the need for a suitable viewing device was soon realized and in 1854 a Frenchman, E.M. Marie-Davy, designed a submarine sight tube containing two mirrors, one above the other, held at the angle of 45 degree and facing in opposite directions. These did provide some degree of sight to the submerged vessels but were rather limited in performance and were hence substituted in 1872 with prisms. The credit for inventing the original periscope goes to Thomas H. Doughty, who developed the basic form during the American Civil War.
The first American submarine to use an internal combustion engine was fitted with 45 horse-power, two-cylinder, four-stroke gasoline engines while the British preferred gasoline engines fitted with 12 or 16 cylinders. The inherent hazards of these engines were soon realized, for stowage was a constant problem and handling of fuel was extremely dangerous. Also, internal explosions were frequent and many of the engines gave off considerable carbon monoxide fumes, creating a menace to personnel.
M.A.N. (Maschinenfabrik Augsberg-Nwinberg A.G.) of Germany had developed a four-stroke diesel engine, capable of producing 1,090 horse power but all these engines developed structural weaknesses in the crankcase. Until 1930 the engines used in most submarines of all the larger naval powers with the exception of Great Britain were four-stroke diesels.
With the development, however, of fleet type submarines, the need for more powerful engines became apparent and eventually a 16-cylinder single-acting engine was developed as well as a 9-cylinder double-acting engine. The fact that submarines are both surface and sub-surface vessels places definite restrictions on size, hull design and shape. The total weight of the submarine is also a factor having considerable bearing on underwater operations. In the first engine powered submarine, the engines were mechanically connected directly to the propeller shafting. It, however, became apparent after testing various types and designs, that the diesel-electric drive was the best. In this type, the engines were connected only to the generators, which in turn supplied power to the main motors driving the propeller shafting. Another function of the generators was charging the storage batteries.
Today's fleet type submarines are generally powered by four main propulsion diesel engines, each capable of driving a generator producing around 2,000 horse-power which in turn drives a slow-speed motor or charges a bank of batteries. An auxiliary engine is also available for driving the generators.
As is known, the conventional submarine does not use the diesels or generators while submerged, and power for the motors is supplied by two sets of storage batteries, which are charged by the auxiliary and main generators during surface operations. The two main storage batteries consist of two groups of over 100 cells each, each one of these cells weighing several quintals.
During the latter part of World War II, the Germans adopted a radical change in submarine design known as the 'schnorkel' -an invention made by the Dutch in 1936 for replenishing air supply of the crew of their submarines. The spelling was simplified by the Americans to 'snorkel' and further abbreviated by the British to 'snort'. The Germans were forced to develop the new device because of the rapid strides already made in the development of improved sonar (underwater sound-aided detecting and ranging equipment) and radar, used by the Allied aircraft and surface vessels against German vessels.
The schnorkel was originally a breathing tube which was raised while the submarine was at periscope depth. When it was raised in position, air for the crew was obtained from the surface. In 1944 the Germans equipped their submarines with double-tube schnorkels, one for Jetting in air for the submarine's diesel engines and crew and the other as an exhaust for diesel fumes, carbon dioxide and other pollutants. The intake tube projected by a foot or so above the sea surface while the exhaust gases were discharged into the sea. This considerably reduced the visible portion of the submarines and also consumption of electric power, since the submarine could cruise almost totally submerged on its engines and conserve its battery power for attacks and evasive measures.
The schnorkel had only one drawback. While by itself it was too small to be spotted from a distance or from the air ii left a distinct wake which could be visually picked up from an antisubmarine ship or aircraft in calm weather. It could also be detected by the radar fitted on ships or aircraft. Darkness or fog could not provide any camouflage any more.
The United States Navy developed an improved schnorkel and also the 'guppy' submarine at the end of World War II. The guppy (greater underwater propulsion power) had the same type of hull as that used for the fleet submarine of World War II fame, was 306 feet long and displaced about 1,800 tons. The only change in the hull was in the superstructure which was radically changed by reducing the surface and streamlining every protruding object. The life lines and all guns were removed, the bitts (posts) to which ropes were secured were made retractable and the periscope shears (supports) enclosed in a streamlined metal fairing. All topside armament and equipment were
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