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Just as men always dreamed of building a flying
machine and conquering the air, inventors five hundred years ago were attempting to build a submersible boat or
submarine out of a desire to conquer the space beneath our seas and
oceans. As with the flying machine, technology at that time was just not sophisticated enough to create
a submarine that worked.
Several were built, with varying degrees of
success. English scientist William Bourne wrote, in 1578, of the possibility of constructing a boat that could descend and ascend by utilising ballast
tanks, but he never built one.
In 1620, a Dutchman by the name of
Cornelius van Drebbel built several prototypes propelled by oars. He used animal skins to make watertight joints and
seams. In the hope of selling his idea to the English he demonstrated his inventions under the River Thames in
London.
Historians agree that Cornelius van Drebbel built the first manouverable
submersible craft.
From a military point of view, the cloak of invisibility acquired by a vessel able to navigate below the surface of the sea was an
irresistible spur to encourage inventors. The next two centuries saw many attempts to build true submersible warships by
France, Britain, Germany and America with very little success.
The Americans came close to a practical submarine at the end of the 18th
century when, as we mentioned briefly in the last issue, David Bushnell invented and built the
'Turtle'. This vessel was just big enough for one man to be enclosed
inside it. It was constructed of wood and was propelled by a hand cranked
propeller. Its weapon was a large explosive charge that could be screwed to the bottom of an enemy ship.
In 1776 the British were blockading New
York and it was decided to use the Turtle to attack H.M.S. 'Eagle'. Ezra Lee a
sergeant in the Continental army made the attempt but was thwarted when he was unable to screw the explosive charge onto the Eagle's
hull. As with most British warships at that time H.M.S. 'Eagle' was copper bottomed.
Ezra and the Turtle escaped in one piece, as did H.M.S. 'Eagle'.
America continued to pursue the goal of a reliable submersible warship and, in 1800, Robert Fulton built a 21ft submarine called the
'Nautilus'. She differed from her predecessors by having rudders for vertical and horizontal
control and, incredibly for the period, compressed air for a submerged air
supply. 'Nautilus' was hand driven through a crank to a propeller. On the surface she could be sailed using a collapsible mast.
During the Civil War, the Confederates built several small submarines known as
'David's (after David Bushnell). The 'H. L. Hunley', built in 1862, was sent on an
anti-blockade mission on the 7th February 1864 and attacked the steamship sloop
U.S.S. 'Housatonic', anchored off Charleston, South Carolina.
'H.L. Hunley' had an explosive charge fixed on the end of a pole, known as a spar torpedo, on the front of the
craft. The mission had mixed results. The 'H.L. Hunley' blew up the U.S.S
'Housatonic' and itself in the process.
Some years later, when divers were sent down to examine the wreck of the
'Housatonic', they found the wrecked 'David' , 'H.L. Hunley', lying on the bottom
nearby, with the remains of her crew of nine men still inside her.
During the latter part of the nineteenth century, there were many attempts to develop a reliable source of
propulsion. Steam, electricity and even compressed air were tried.
John Philip Holland, an Irish/American scientist, developed the first practical submarine with an efficient source of
power above and below the surface, a dual propulsion system, with a petrol driven internal combustion engine for surface use and electrical power whilst
submerged. The 53' vessel was launched in 1898.In 1900, the United States Government purchased the boat and named her the U.S.S
'Holland'.
It is interesting to note that the first five submarines built in Britain were
of Holland's design. They displaced 105 tons on the surface and had surface and submerged speeds of 8.5 and 7 knots
respectively.
In Germany, it was decided to wait for the perfection of the, much safer,
diesel engine before embarking on the construction of the long line of U-boats
(short for Unterseeboot) which were to play such an important part in the two World Wars.
At the outbreak of the first World War, submarines had evolved into reliable and deadly machines of
war, both sides sinking massive tonnages of shipping. Cunard shipping,
for example, lost a quarter of a million tons. The Germans, especially, proved just how effective their
U-boats were, by putting a strangle hold on shipping and supply routes, and nearly crippled Britain in the
four-year conflict.
Twenty years later, at the start of World War
II, the advances in submarine technology included better torpedo design,
communications and, in the German U-boats, an 88mm deck gun and anti-aircraft guns were
fitted.
Germany also invented the Snorkel. Having realised that submarines were at
their most vulnerable when on the surface, whilst running their diesel motors to charge their battery
banks, they fitted a tube with which the motor could 'breathe' whilst the
U-boat was at periscope depth - approximately 60 feet - and therefore less likely to be spotted by enemy ships or planes.
Shipping losses caused by submarines in this war were astronomical.
Japan, for example, lost 4.75 million tons of shipping, 55% of their
wartime shipping losses, to submarine attacks.
At the close of the second World War the
U-boats that were captured by the Allies were scrutinised and many of the innovations in these advanced
diesel electric submarines were
incorporated in the vessels of both the United States and Soviet navies.
With the exception of better streamlining (meaning more
speed, larger battery banks, improved torpedoes, and under water
manouverability), the submarine didn't change much until the advent of a nuclear reactor that was small enough to be used as the driving force of a submarine.
The knowledge gleaned from five centuries of invention and
the testing of these conventional military submarines is now being utilised for peaceful oceanographic
and seismic exploration, construction, salvage and rescue vessels.
In the next issue we'll talk about some
of the awesome 21st century, nuclear powered, submarines that can travel 450,000 miles between refueling and circumnavigate the globe
submerged...Eat your heart out, Ezra.
Keith Robinson for MarineZine
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