S90-class torpedo boat

The S90 class of torpedo boats was a group of large torpedo boats built for the German Imperial Navy (Kaiserliche Marine) in the early 20th century. They were Hochsee-Torpedoboot ("High seas torpedo boat") built to varying designs by Germaniawerft, Schichau, and AG Vulcan. German torpedo boats were designated by shipbuilder, with the first letter of their designation reflecting their builder.

General characteristics and machinery


The boats of the S90 class varied in dimensions, and they gradually increased in size as more vessels were built. The boats were 62.7 to 68.5 m long at the waterline and 63 to 71.5 m long overall. They had beam (nautical) of 7 to 7.65 m and a draft of 2.03 to 3.22 m. The hull for each boat was divided into eleven watertight compartments, though after SMS G132, a twelfth compartment was added. They had a crew of two officers and fifty-five enlisted men, though some of the boats had larger crews; SMS S120 had four more sailors, while G132 had twelve more men, and SMS G131 had a crew of three officers and 78 enlisted. When serving as half-flotilla flagships, the boats would have a flotilla leader's staff of four officers and eleven enlisted men in addition to the standard crew. The vessels carried a yawl and a dinghy apiece.

The S90-class boats were propelled by a pair of vertical, 3-cylinder triple expansion steam engines that drove a pair of three-bladed screw propellers. Steam was provided by three coal-fired water-tube boilers. Two boats, SMS S125 and SMS G137, were fitted with Parsons steam turbines instead of the older reciprocating engines; G137 also received an additional boiler. The reciprocating engine-powered boats were rated at 27 to 30 kn from 5900 to 7000 ihp. Meanwhile, S125 and G137 were rated at 6600 shp and 28 kn, and 10800 shp and 30 kn, respectively. The boats had storage capacity for 93 to 168 MT of coal. As a result, cruising radius varied significantly, from 830 to 1500 nmi at 17 kn. Each vessel was equipped with one or two 4 to 8 kW 110-Volt generators for electrical power. Steering was controlled with a pair of rudders, one at the stern and the other in the bow.

Armament
Most of the ships of the class were armed with a main battery of three 5 cm SK L/40 guns in single pivot mounts. They were supplied with a total of 252 shells that weighed 1.75 kg. The guns had a muzzle velocity of 656 m/s and a maximum range of 6200 yd at their highest elevation of 20 degrees. G132, SMS G133, SMS G134, and SMS G136 were equipped with four 5.2 cm SK L/55 guns in single gun mounts. These guns fired a similar 1.75 kg shell at a muzzle velocity of 850 m/s. The guns could elevate up to 20 degrees, at a maximum range of 7100 m. SMS G135 was equipped with two of the 5.2 cm guns and one 8.8 cm gun, while SMS G137 had three 5.2 cm guns and one 8.8 cm gun. The 8.8 cm gun fired a shell weighing 7 kg at a muzzle velocity of 690 m/s. The gun could be elevated to 25 degrees, for a maximum range of 8790 m. Many of the boats were rearmed throughout their time in service, trading their 5 cm or 5.2 cm guns for the more powerful 8.8 cm guns. All ships of the class carried three 45 cm deck-mounted single torpedo tubes with five torpedoes.