Torpedo: The Complete History of the World's Most Revolutionary Naval Weapon

^{Right: A view of the launch ramp at Fort Ricasoli. The launch rails and their supports have long since vanished, and the opening in the torpedo station building, through which the torpedoes were launched, has been filled in with stonework closely resembling the wall of the building itself. When the station was operational this aperture would have been closed by a sliding armoured door. (Photo courtesy of David Moore)}

^{The Brennan defences of Grand Harbour. (Photo from Google Earth annotated by the author)}

^{Another of David Moore’s photos, showing the rampart of Fort Ricasoli on the right, with the torpedo launch slot at its base. The launch building is to the immediate right of the photo. On the rampart wall itself can be seen the remains of the support brackets for the launch girder. Above them the wall bears evidence of at least a weatherproof cover, if not an armoured mantlet. The entrance to Grand Harbour is to the right behind the end of the rampart wall.}

Although it sounds like a complicated procedure, it actually worked extremely well in practice. The Royal Engineers were tasked with running it, and they were extremely pleased with all this ‘engineering’. However, compared with a simple torpedo tube on a pivoting mount, served if necessary by an air compressor to recharge the torpedo’s air flask, the Brennan station was extremely complex and, moreover, prohibitively expensive, considering the need to provide for a boiler, a steam engine, a condenser to avoid giving away the position by allowing steam to vent to the air, a winding and steering engine, and a vulnerable launch girder supporting the pulley carriage. One can see why the number of installations was never increased.

^{A drawing by David Moore showing one of the weapons on its rails, sighting mast raised into position and held by stays, and ready for launch. (Courtesy of David Moore, based on an original by Alec Beanse, first published in The Brennan Torpedo by Alec Beanse)}

As a footnote, the record of servicemen deaths on Malta notes the funeral of Sapper Gillies, Royal Engineers, held on 8 November 1900. He was endeavouring to recover a torpedo lost outside Grand Harbour. As he was RE instead of RN it must be assumed that this was a Brennan, and from the location it would have been launched from Fort Tigné. The report goes on to state that the depth was extreme but he was a powerful man, and had managed to find the torpedo, signalling that he had done so. By some accident the apparatus sent down to be attached to the torpedo fouled his life line with the result that he became unconscious. He was quickly brought to the surface and taken to the station hospital but he died two hours later.

The type of diving suit used by Sapper Gillies can be seen in the first photo of the Brennan torpedo in the Royal Engineers Museum (see Chapter 5).

SHORE-BASED TORPEDO TUBES

North Kaholmen torpedo battery, Oslo Fjord, Norway

North Kaholmen torpedo battery is part of the Oscarsborg Fortress, the main defensive work protecting the Norwegian capital at the head of Oslo Fjord. The battery was excavated out of the solid rock between 1898 and 1901. Doubtless the Germans planning for the invasion of Norway in 1940 knew of the three old Krupp guns installed in 1898, but the torpedo battery, a closely guarded secret, was invisible and completely unexpected.

Torpedoes arrived at the battery by way of a square stone-built quay, equipped with a small crane. The entrance to the battery was protected by armoured double doors, which were shielded from view from a vessel passing up the fjord by a concrete protecting wall. Above the entrance was a plaque bearing the date ‘1911’.

^{The Whitehead Company in Fiume not only built torpedoes, but also the launch tubes for the Austro-Hungarian navy. Here is a drawing from an official manual, showing a land-based torpedo tube from 1896, installed for coastal defence. (Drawing courtesy of Erwin Sieche)}

^{The Austro-Hungarian torpedo battery at Mali Brijun, Istria, Croatia. Constructed as part of the outlying defences of the naval base at Pola. The main fort is on the high ground to the left, with heavy gun batteries. (Photo courtesy of Dalibor, brch photography, Croatia)}

^{The defences of Oslo Fjord seen on Google Earth (annotated by the author). The main armament of the Oscarsborg Fortress was three 280mm (11in) Krupp breech-loading guns. To the east of the island, on the mainland, were sited two batteries of 6in and 57mm QF guns. The torpedo battery on North Kaholmen is completely invisible.}

^{Plan of the North Kaholmen battery, showing the three underwater torpedo launch tunnels and the vertical shafts to the three aiming towers sited 10m (33ft) above the launch bays. In addition to the torpedo body and warhead storerooms, there were a compressor room, a generator room and a torpedo workshop. During the Cold War period a crew accommodation apartment was added. (The interior photos and drawings of the torpedo battery have been provided courtesy of Kjell J Glosli)}

^{The torpedo leading sight (‘Siktetriangel ’ in Norwegian) from one of the aiming towers. The target’s speed and course were calculated and plotted on the bar extending to the right. The V-notch is the forward sight, and when it is aligned on the target the torpedo is launched. The central bar, which trains up to 12½ degrees to left and right, gives the torpedo track.}

^{The torpedo launching gear, comprising a V-shaped steel framework holding two bronze torpedo launch frames side by side at the upper level. The pulleys and chains lower the loaded launch tubes one at a time to the centre of the launch tunnel at a depth of 4m below the water level. The frame pivoted up to 121/2 degrees to left and right of the centre-line. There was no need of compressed air: the torpedo engine was started and it swam out of the frame and into the tunnel. This meant there was no escape of compressed air to give away the battery and the launch.}

Today, the battery is a museum forming part of the Oscarsborg Fortress complex. Its torpedo store contains British Mark VIII torpedo bodies, and a separate warhead store has their warheads, practice heads and firing pistols. In April 1940 the battery was armed with nine Whitehead Mk Vd torpedoes.

Along with the rest of the Oscarsborg Fortress, the torpedo battery led a quiet existence for some forty years, punctuated only by the regular summer training exercises. Since its installation the crews had carried out over two hundred torpedo launches with exercise heads. All that would change dramatically on 9 April 1940 (for details of the action, see Part IV).

The Spinne

‘Spinne’ is German for ‘spider’, and with the usual German penchant for allocating codenames which contained an element of the device they were intended to conceal — unlike the British attitude of allocating entirely arbitrary codenames — the torpedo controlled by the Spinne coastal stations spun a length of wire out behind it as it ran. Building on their Great War experience of the FL-boat and the Siemens-Schuckert glider torpedo, in 1944 the Germans decided to install a large number of coastal stations to house, launch and control the T10 wire-guided torpedo.