She was the lead ship of the first British A-class submarines (a second, much different A-class appeared towards the end of the Second World War), and the only one to have a single bow torpedo tube. She was actually sunk twice: first in 1904 when she became the first submarine casualty, with the loss of all hands; however, she was recovered, but sank again in 1911, this time when she was unmanned. The wreck was discovered in 1989 and is now a protected wreck.
If you look underneath the hull right at the bow it is possible to see the simple clasp that when released would
have allowed the single front torpedo tube to open. The A1 carried one 18in torpedo tube in bow, with two reloads (total of three),
but the submarine is not thought to have been carrying torpedoes when it was lost.
Torpedo Door Opening Mechansim
Looking down at the upper works at the bow it is possible to see the mechanism that pulled back and opened the torpedo tube bow
cap. This is exactly the same system visible on the earlier Holland class submarines. Originally this mechanism would have been
covered by a thin upper casing but this has corroded since the A1 sank in 1911.
Torpedo Loading Hatch Openings
Between the bow and the conning tower at the upper most part of the pressure hull there are two rectangular holes. This is the torpedo
loading hatch area which is now missing a door. Inside the hull, the submarine is filled with silt and it is not recommended to enter.
Forward Conning Tower Crack
At the base of the conning tower it is possible to see a crack which runs upwards. This crack is recorded by visiting archaeologists
and divers at regular intervals to see if the crack is lengthening or widening.
Water & Fuel Filler Inlets Rear of Conning Tower
Around the top parts of the hull it is just about possible to find various inlets which would have been for water and fuel
Exhaust & Rear Communications Mast
Before reaching the stern of the visible remains it is clear that the upper parts of the hull have either corroded away or been
damaged. As a result you can now see the remains of pipes running back to the stern. It is possible that these are engine
Single Torpedo Tube
The A1 was the lead ship of the first British A-class submarines (a second, much different A-class appeared towards the end of the Second World War), and the only one to have a single bow torpedo tube.
The A1 had only one 18 inch torpedo tube in the bow, and had two reloads (total of three). The A1 is not thought to have been carrying any torpedoes when it was lost.
The batteries were installed to drive an electric motor when the A1 was submerged. The electric motor allowed the A1 to reach a maximum speed of 7 knots when submerged. At a cruised speed of 5 knot the A1 could travel 20 nautical miles when submerged
Air Ballast Tanks
Although a large number of air ballast tanks are placed throughout the length of the submarine it has been stated that the A class submarines only had a "tiny reserve for buoyancy" (Ackerman 1989 Encyclopaedia of British Submarines 1901-1955).
16 Cylinder Wolseley Gasoline Engine
The A1 was fitted with a 450 horsepower (340 kW) engine and a 87 horsepower (65 kW) (electric motor). On the surface it was propelled with the 16-cylinder Wolseley engine which could reach a maximum speed of 11.5 knots with a surface range of 500 nautical miles. As no existing engine of a suitable size already existed, the Wolseley company set out to build an engine capable of reaching an unprecedented 500 bhp. Some sources suggest that the A1 actually had a 12 cylinder engine rather than 16 cylinders.