The torpedo heads were covered by the deck amidships, and they were launched backwards by a cordite-powered ram with an aluminium cap which surrounded the torpedo head. The torpedoes were fitted with side lugs which rested on rails running the length of the trough, and which extended beyond the stern of the boat to carry the torpedo head clear of the stern on launch. Before launching, the torpedoes were clamped in place by securing arms which pivoted upwards to release the torpedo.
Despite the bravery of their crews, these G5 boats achieved limited success against Axis shipping due to the inherent disadvantages of the stern trough launch system. An additional problem was the fact that, without an auxiliary engine for slow-speed manoeuvring, the boats would not run at less than 18 knots, making slow approaches to the target impossible.
Some seventy-five boats would be lost out of a total production of 300 in the Baltic, Northern and Black Sea fleets. Of the boats transferred to North Korea, three were destroyed in July 1951 in action with USS Juneau, HMS Jamaica and HMS Black Swan off Chumunjin.
A variant on the CMB launch system was fitted to Q-ships, to allow them to attempt to torpedo an attacking U-boat. The 18in torpedo (K) was carried in a cradle between the supports. Dropping the hatch (P) in the ship’s side, and firing the cordite charge in the vessel (I) activated the ram (C).The head of the ram (G) propelled the cradle and the torpedo forward, and ejected the weapon through the hatch. One had to hope the U-boat was not too far off.
The first Royal Navy motor torpedo boats to be constructed following the Great War, the 60ft British Power Boat MTBs of 1936 were a curious design. They copied the launch dispositions of the CMBs, with the torpedoes launched tail-first from the stern of the boat, but with the torpedoes carried internally in the engine rooms — a strange arrangement which at least kept them warm and dry.
However, in place of the CMBs’ cordite-powered launching ram, which propelled the torpedo at speed into the water behind the boat, the BPB 60-footers had folding launch gantries which extended back over the transom, carrying extensions of the overhead rails from which the torpedoes were suspended in their internal tunnels. In order to launch, it was necessary to point the boat in the required direction, release the torpedo holding catch, leaving the weapon free to move backwards and downwards, then accelerate the boat to make the torpedo slide backwards out of the transom. Naturally, the boat would then execute a rapid turn to port or starboard to avoid her own torpedoes.
Just as with the CMBs, this launch method went contrary to all the precepts of the small, vulnerable wooden torpedo boat, filled with petrol, whose only advantage lay in small size and a silent stalking approach to avoid alerting the target. Crash-starting the engines and throwing up a huge bow wave could be fatal. The boats did their best to combat the Japanese attacking Hong Kong, but their situation was hopeless. The experiment was not repeated by the British.
A similar arrangement was to be found on the LS-boats (‘Leicht-Schnellboote’, or ‘light speedboat’) designed to be carried on German auxiliary cruisers. Too small to carry the standard S-boat torpedo tubes and 21in torpedoes, most carried three minelaying tubes, but LS 4 Esau, which was hoisted aboard raider Michel, was armed with two 450mm (18in) torpedoes carried in internal tubes at the rear of the boat. The LS-boat weighed 12 tons and was capable of speeds up to 42 knots. The lack of the type of rear extension rail as on the 60ft BPB boats suggests that the LS-boats launched their torpedoes by a normal black powder charge or by compressed air, facing sternwards. Launching them backwards at high velocity would cause serious derangement of the control mechanisms, to say nothing of the detonator in the nose, so they would be launched nose-first through the transom hatches, having first pointed the boat at the target. Since most attacks were carried out by LS 4 at night, stalking unsuspecting merchantmen, sternward launches would cause no problems.
CHAPTER 10
Torpedo Boat Carriers
CAPITAL SHIPS
Very early in the story of the Whitehead, the Royal Navy saw the offensive potential of the locomotive torpedo. As well as cutting ports in bulwarks for torpedo launch carriages, they attempted to extend the reach of their torpedoes by carrying onboard small craft capable of attacking an enemy fleet at night or in a defended harbour.
In 1879 HMS Devastation, followed by her sister ship HMS Thunderer two years later, was supplied with a steam cutter fitted with torpedo dropping gear. In addition, each ship had a port cut in their breastwork armour on each side for torpedo launching carriages. An outfit of twelve Whiteheads was carried by each ship. In 1880 HMS Sultan was fitted with four carriages for 14in Whiteheads on her main deck, and two torpedo boats were added, stowed abreast the after mast on crutches. In 1881 HM Ships Hotspur, Ajax and Agamemnon were fitted for torpedo launching and received a 60ft torpedo boat each, as was HMS Conqueror five years later. The massive turret ship HMS Inflexible in 1881 became the first British ship to be fitted with two submerged torpedo tubes (in the bow), in addition to two above-water launch carriages, a bow torpedo launch skid and a stern launch derrick. She also carried two 60ft second-class torpedo boats, specifically for ‘night attacks’. And even as late as 1906 HMS Dreadnought stowed in her forward torpedo flat not only the 18in torpedo bodies and warheads for her own underwater tubes, but also 14in torpedoes for her ship’s boats.
Ironclads usually had sufficient deck space, and the necessary heavy lifting derricks, to carry small torpedo craft. Smaller vessels such as cruisers could not, so both the British and French attempted to give mobility to the short-range coast-defence torpedo boats by hoisting them aboard special torpedo cruisers.
Interestingly, in 1810 Robert Fulton described a similar plan he had devised six years earlier for the attack on Boulogne. Because the ships of the line at that time did not have the deck space to transport additional craft designed specifically for torpedo attacks, Fulton had asked for four ‘ordnance vessels’ to be prepared, with large hatchways to carry torpedo boats internally, together with a supply of torpedoes.