Storozhevoy-class destroyer

The Storozhevoy class were a group of 18 destroyers built for the Soviet Navy in the late 1930s. The Soviet designation was Project 7U (Uluchshennyi (Improved)). The ships fought in World War II. The design was finalised in 1936 after initial disappointments with the. The main changes were unit machinery (four boilers instead of three), a strengthened hull and reduced fuel capacity. The anti-aircraft guns were repositioned to improve firing arcs.

Background and description
Naval historians Yakubov and Worth state that the change to unit machinery was due to an incident when the British destroyer HMS Hunter (H35) was stopped due to machinery damage by a mine during neutrality patrols in the Spanish Civil War. The incident reported at a meeting where Joseph Stalin was present and he ordered that the ships be redesigned with unit machinery so that a ship could still move if one of the two boiler or engine rooms were incapacitated. This change in design saved SOVIET DESTROYER Slavny following mine damage in 1941, but led to a considerable delay in the Soviet destroyer program and the cancellation of six Type 7 ships. Fitting the additional machinery in the same hull presented significant challenges, leading to an increase in weight, cramped accommodation and a reduction in fuel capacity. These changes led Soviet sailors to nickname the Type 7U, 7 Ukhudshennyi (ухудшенный, made worse).

The Storozhevoys had an overall length of 112.5 m, a beam of 10.2 m, and a draft of 3.98 m at deep load. The ships were slightly overweight, displacing 1727 MT at standard load and 2279 MT at deep load. Their crew numbered 207 officers and sailors in peacetime and 271 in wartime.

The ships were powered by two geared steam turbine sets, each driving a single three-bladed 2.9 m propeller using steam provided by four water-tube boilers that operated at a pressure of 26.5 kg/cm2 and a temperature of 350 °C. The turbines, rated at 54000 shp, were intended to give the ships a speed of 38 kn. The designers had been conservative in rating the turbines and many, but not all, of the ships handily exceeded their designed speed during their sea trials. SOVIET DESTROYER Storozhevoy reached 40.3 kn during her trials in 1941, but SOVIET DESTROYER Soobrazitelny only managed 36.8 kn. Variations in fuel oil capacity meant that the range of the Storozhevoys varied between 1380 to 2700 nmi at 19 kn.

Armament and fire control
As built, the Storozhevoy-class ships mounted four 50-caliber 130 mm B-13 guns in two pairs of superfiring single mounts fore and aft of the superstructure. Each gun was provided with 150 rounds. The development of the gun was troubled by excessive barrel erosion problems and three variants were built in a not entirely successful effort to resolve the problem which complicated logistical and operational support as each performed slightly differently. The manually operated mounts had an elevation range between -5° to +45° and had a rate of fire of 6–10 rounds per minute. They fired a 33.4 kg shell at a muzzle velocity of 870 m/s, which gave them a range of 25597 m.

Anti-aircraft defense was provided by two 55-caliber 76.2 mm 34-K AA guns and three 46-caliber 45 mm 21-K AA guns, all in single mounts as well as four 12.7 mm DK or DShK machine guns. The 34-K guns could elevate betwwen -5° and +85°, had a rate of fire of fire of 15–20 rounds per minute, and the ships carried 300 rounds per gun for them. Their muzzle velocity of 801 m/s gave their 11.9 kg high-explosive shells a maximum horizontal range of 14640 m and an effective ceiling of 6500 m. The 21-K was a converted anti-tank gun with a rate of fire of 25–30 rounds per minute with an elevation range between -10° and +85°. The gun fired a 1.41 kg shell at a muzzle velocity of 760 ft/s. This gave them a range of 9200 m. The Project 7Us stowed 500 rounds for each gun. The DShK had an effective rate of fire of 125 rounds per minute and an effective range against aircraft of 2500 m.

The ships were equipped with six 533 mm torpedo tubes in two rotating triple mounts amidships; each tube was provided with a reload. The Project 7U-class ships primarily used the 53-38 or the 53-38U torpedo, which differed only in the size of their warhead; the latter had a warhead 100 kg heavier than the 300 kg warhead of the 53-38. The torpedoes had three range/speed settings: 10000 m at 30.5 kn; 8,000 m at 34.5 kn and 4,000 m at 44.5 kn. The ships could also carry a maximum of either 60 or 96 mines and 25 depth charges. They were fitted with a set of Mars hydrophones for anti-submarine work, although it was useless at speeds over 3 kn.

Fire control for the main battery of the Storozhevoys was provided by a Mina-7 fire-control system that was derived from an Italian Galileo system. It included a TsAS-2 mechanical analog computer that received information from a KDP2-4 gunnery director on the roof of the bridge which mounted a pair of DM-4 4 m stereoscopic rangefinders. Anti-aircraft fire control was strictly manual with only a DM-3 3 m rangefinder to provide data to the guns. Some ships received the Soyuz high-angle fire-control system for the 34-K guns. It consisted of a mechanical analog computer, a Gazon vertical gyroscope and an SVP-29 stabilized viewfinder. The system could handle targets like bombers flying level, but was useless against aircraft attacking in a dive.

Modifications
Later in the war electronic equipment such as radar and sonar were supplied by the Allies for these ships.