However, submerged tubes did pose several problems, most of which were overcome in the latter part of the nineteenth century. First, there was the problem of watertight integrity. The tube itself would be closed at the sea end either by a hinged flap, or a vertical or horizontal sluice gate. Launching from bow- and stern-mounted underwater tubes was simplified, unless the launching vessel was under tight helm at the moment of firing. This would be unlikely, since aiming was critical. Beam tubes were a different matter. Launching a torpedo broadside-on, or at a slight angle to the keel, exposed the missile to a severe risk of damage or at the very least of diverting it from its planned trajectory because of the motion of the launching ship.
All navies overcame this problem by arranging a support arm, commonly called a spoon (‘cuillère’ in French terminology) or bar, which extended from the launch tube in front of the torpedo and guided the weapon out into the water. A version favoured by Whitehead Fiume was a circular cage which extended to enclose the emerging torpedo. The Armstrong system was similar but comprised an extending slotted tube.
One major problem was, however, never satisfactorily resolved. Bow torpedo tubes tended to weaken the bow structure just where total integrity was required to survive ramming damage or, more usually, grounding incidents. But more serious was the temptation to install spacious underwater torpedo compartments, to be able to keep up a sustained series of launches on either beam. These were difficult to arm, necessitating the arrangement of torpedo loading passageways through the relevant section of the ship (the German preference seemed to be to load the torpedoes vertically), and offered a large space liable to flooding, either through torpedo or mine damage or by a malfunction of the flap or sluice gate. The Kaiser is said to have personally intervened following the flooding of the forward torpedo compartment on the Baden when she was mined in 1917, and demanded the removal of the torpedo tubes.
A further problem was the need to evacuate the seawater entering the tube on each firing. To reload a beam tube, the spoon arm would be withdrawn, the flap or sluice gate closed, and the tube vented to the surface prior to opening. French and Austrian torpedo tubes loaded through a rear door while German and American tubes split lengthwise with pivoting side segments. HMS Dreadnought was fitted with a third variant, the first of the 18in Type B, with both a tube splitting lengthwise and a rear ‘chopper’ door. As Dr Oscar Parkes commented, when describing HMS Agincourt in action at Jutland, rapid fire necessitated leaving out the venting sequence, so when the tube was opened for reloading, its water content would spill into the firing compartment. Continuous action could lead to the torpedo-men working in up to 3ft of water.
When the early American dreadnoughts were being reconstructed between the wars, it was deemed prudent to remove their underwater torpedo tubes. Thought was given to repositioning these on deck, but the proposal was turned down because of the risk of exposure to enemy gunfire.
The moment of glory for the underwater tube came on 27 May 1941, during the Bismarck’s final action. At 0923 Chief Petty Officer Pollard and his team in the submerged torpedo room of HMS Rodney fired the first of two 24.5in torpedoes from her starboard tube. In all, they fired six torpedoes during the ship’s run to the south, without scoring any hits. A near-miss by one of Bismarck’s 15in shells then damaged the sluice gate and put the starboard tube out of action. Rodney was zigzagging, firing gun salvoes alternately to starboard and port, and she fired two torpedoes from her port tube, at a range of three and a half miles, again without hitting. Nearly at the end of the action Rodney fired the last two of her complement of ten torpedoes, and claimed one hit. If true, this would have been the only time one battleship had actually torpedoed another.
ROYAL NAVY DESIGNS
The groundwork on designing and operating submerged torpedo tubes in the Royal Navy was carried out by Commander Arthur Knyvet Wilson, in charge of HMS Vernon from 1876 to 1881. The future admiral and First Sea Lord would go on to win the Victoria Cross on land at the Battle of El Teb, when the square broke and he fought off the Mahdists with his sword, then with his fists. During his years at Vernon, Wilson invented the bar or ‘spoon’ which enabled underwater broadside tubes to launch without damaging the torpedo.
On 15 June 1881 the Royal Navy launched an extraordinary vessel, the ‘torpedo ram’ HMS Polyphemus: 240ft long (73m) with a displacement of 2640 tons, her cigar-shaped hull was mostly awash when at speed, and her turtle-back was protected by 3in (76mm) armour. A minimal superstructure provided some degree of habitability, and for self-defence she was armed with six 1in Nordenfelt machine guns in circular ‘pillbox’ turrets, later supplanted by the same number of 3pdr (47mm) QF guns. Polyphemus was a fast ship for her day, capable of almost 18 knots, but the most revolutionary aspect was her offensive armament, which comprised five underwater torpedo tubes for 14in Whitehead Mark II torpedoes, of which she carried a total of eighteen. Other innovative features were a drop keel which could be jettisoned in an emergency if the hull was holed, and a pair of large life rafts hung from her boat deck aft of the funnel, which could float free if she sank.
She was built following proposals from Admiral Sir George Rose Sartorius, then in his eighties, who had seen much active service in the Napoleonic wars and later in command of the Portuguese Regent’s fleet in the civil war of 1832–33. Sartorius felt that the introduction of the ironclad could only be effectively countered by the introduction of armoured ram ships.
This connection led to various misconceptions of the role intended for HMS Polyphemus, and perhaps the choice of her name was intended from the start to mislead.
Classical scholars would have known that the mythological Polyphemus was the one-eyed monster who had tried to capture Odysseus and his companions. The wily king of Ithaca had escaped by driving a sharpened tree trunk into the monster’s single eye, blinding him. Just to confuse the issue, of course, HMS Polyphemus carried two eyes like every ancient Greek or Roman galley, so the pundits would immediately realise that it was she who would be carrying the sharpened instrument, her bow, to the enemy in a ramming attack. To help her in this difficult task, she was equipped with two retractable bow rudders — just visible in the dry-dock photo — to enable her to spin like a top.
