Design and description
Tsar Nicholas II had desired a warm-water port on the Pacific since his accession to the throne in 1894. He achieved this ambition in March 1898 when Russia signed a 25-year lease for Port Arthur and the Liaotung Peninsula with China. Japan had previously forced China to sign over the port and its surrounding territory as part of the treaty that concluded the First Sino-Japanese War of 1894–1895, but the Triple Intervention of France, Russia, and Germany forced them to return the port in exchange for a sizeable increase in the indemnity paid by the Chinese. Japan invested much of the indemnity money in expanding its fleet, while Russia began a major building programme ("For the Needs of the Far East") to defend its newly acquired port that included the Borodino-class battleships.
The Borodinos were the most numerous class of battleships ever built by Russia. Although they were intended to be near duplicates of Tsesarevich, as soon as the contracts were signed, it became clear that they would be quite different from the French-built ship. The basic problem facing the navy was that the Borodinos would have heavier engines and larger turrets which would require a designer to build a ship which had the same speed, draft, guns and armor as Tsesarevich, but a greater displacement. The new design was drawn up by D. V. Skvortsov of the Naval Technical Committee (NTC). He completed his new design in July/August 1898, one month after the original contract had been signed. The new concept was roughly 1,000 long tons (1,000 t) tons heavier and slightly larger and wider than the Tsesarevich.
As might be expected, the Borodinos greatly resembled Tsesarevich, although Skvortsov added two more casemates, each containing four 75-millimeter (3.0 in) guns, one at the bow and the other aft. These guns were added to the already existing dozen 75 mm guns emplaced along the sides above the armor belt. This caused the tumblehome used on the rest of the hull to be deleted over the twelve guns and flat-sided armor was used in its place. Thus the five Borodino-class battleships only had tumblehome hulls fore and aft of their 75 mm guns emplaced along their sides. The centreline bulkhead between the engine and boiler rooms caused a danger of capsizing if one side flooded and their narrow belt armor became submerged when overloaded. As such, naval historian Antony Preston regarded these as some of the worst battleships ever built.
The ships were 389 feet 5 inches (118.7 m) long at the waterline and 397 feet 3 inches (121.1 m) long overall, with a beam of 76 feet 1 inch (23.2 m) and a draft of 29 feet 2 inches (8.9 m), 38 inches (965 mm) more than designed. Their normal displacement ranged from 14,091 to 14,145 long tons (14,317 to 14,372 t), 500–900 long tons (508–914 t) more than their designed displacement of 13,516 long tons (13,733 t). They were designed for a crew of 28 officers and 754 enlisted men, although Knyaz Suvorov carried 928 crewmen during the Battle of Tsushima.
The Borodino-class ships were powered by two 4-cylinder triple-expansion steam engines, each driving one propeller shaft, using steam generated by 20 Belleville boilers. The engines were designed to reach a top speed of 18 knots (33 km/h; 21 mph). The lead ship, Borodino, was fitted with a copy of the La Seyne machinery installed in Tsesarvich and built by the Franco-Russian Works. The remaining four Borodinos were supplied with machinery designed and built by the Baltic Works. Borodino's engines were rated at 16,300 indicated horsepower (12,200 kW) and its boilers had a working pressure of 19 atm (1,925 kPa; 20 kgf/cm2); the machinery of her sisters was rated at 15,800 ihp (11,800 kW) and their boilers had a working pressure of 21 atm (2,128 kPa; 22 kgf/cm2). Other differences were that Borodino was equipped with economisers for her boilers as well as three-bladed screws, while her sisters lacked economisers and had four-bladed propellers.
Because the ships were being prepared to go to the Far East shortly after completion, they conducted only abbreviated sea trials. Only Oryol reached her designed speed during these trails, despite her engines only producing 14,176 ihp (10,571 kW). The engines of her sisters produced more power, but they were slower during their trials. At deep load they carried 1,350 long tons (1,372 t) of coal that provided them a range of 2,590 nautical miles (4,800 km; 2,980 mi) at a speed of 10 knots (19 km/h; 12 mph). The ships were fitted with six steam-driven generators with a total capacity of 738 kilowatts (990 hp).
Armament and fire control
The main armament of the Borodino class consisted of two pairs of 40-caliber 12-inch guns mounted in French-style, electrically powered, twin-gun turrets fore and aft. The turrets had a maximum elevation of +15° and 60 rounds per gun were carried. The guns fired one shell every 90–132 seconds. They fired a 731-pound (332 kg) shell at a muzzle velocity of 2,598 ft/s (792 m/s) to a range of 16,010 yards (14,640 m) at maximum elevation.`
The secondary armament of the ships consisted of a dozen 45-caliber Canet Model 1891 6-inch (152 mm) (QF) guns mounted in six electrically powered twin-gun turrets on the upper deck. The turrets had a maximum elevation of +15° arc of fire and the center turrets could cover 180°. Each six-inch gun was provided with 180 rounds. Their rate of fire was about 2–4 rounds per minute. They fired shells that weighed 91 lb (41.4 kg) with a muzzle velocity of 2,600 ft/s (792.5 m/s). They had a maximum range of approximately 12,600 yards (11,500 m).
A number of smaller guns were carried for defense against torpedo boats. These included twenty 50-calibre Canet QF 75-millimetre (3 in) guns mounted in hull embrasures. The ships carried 300 shells for each gun. They fired a 11-pound (4.9 kg) shell at a muzzle velocity of 2,700 ft/s (820 m/s) to a maximum range of 7,005 yards (6,405 m) at an elevation of +13°. The Borodino-class ships also mounted sixteen or eighteen 47-millimetre (1.9 in) Hotchkiss guns in the superstructure. They fired a 2.2-pound (1.00 kg) shell at a muzzle velocity of 1,400 ft/s (430 m/s) at a rate of around 15 rounds per minute.
The ships carried four 381-millimetre (15 in) torpedo tubes, two of which were mounted above water in the bow and stern while the two broadside underwater tubes were located near the forward 12-inch magazine. Four torpedoes were carried for the above-water tubes and six for the submerged tubes. They also carried 50 mines to be laid to protect their anchorage in remote areas.
The Borodino class were originally fitted with Liuzhol stadiametric rangefinders that used the angle between two vertical points on an enemy ship, usually the waterline and the crow's nest, to estimate the range. The gunnery officer consulted his references to get the range and calculated the proper elevation and deflection required to hit the target. He then transmitted his commands via a Geisler electro-mechanical fire-control transmission system to each gun or turret. While fitting out, these rangefinders were replaced on the first four ships by two Barr and Stroud coincidence rangefinders that used two images that had to be superimposed to derive the range. Perepelkin telescopic sights were also installed for their guns, but their crews were not trained in how to use them.
The waterline armor belt of the Borodinos consisted of Krupp armor and was 5.7–7.64 inches (145–194 mm) thick. The armor of their gun turrets had a maximum thickness of 10 in (254 mm) and their deck ranged from 1 to 2 inches (25 to 51 mm) in thickness. The 1.5-inch (38 mm) armored lower deck curved downwards and formed an anti-torpedo bulkhead.