Russian Minelaying Submarine (1915-1919)New Cycle ! Russian submarines from 1865 to the revolution. The Russian Imperial Navy was a pioneer in submarines, having the first operational models just after the US Civil war experiments, like the HL Hunley and USS Alligator. Alexandrosvky (1865) was followed by the fifty plus Drzewiecki midget subs for the Russian-Ottoman war of 1878, and many more classes prior or during the Russo-Japanese war of 1905. All types were tested, American, Italian or German types before the mass-construction of the Bars class in 1915 as part of the 1912 programme. Still one of the most interesting of all these by far was a prototype, Krab. This was in July 1915, the world’s first minelayer submarine to be built (launched) it inspired, but was overtaken in operation by the German UC class, which savaged entente shipping and led to the construction of follow-up UC-II and UC-III. But Naletov’s (or Nalyotov) design inspired them all.
Krab in 1916
Development
About Mikhail Petrovich Nalyotov
Mikhail Petrovich Naletov (1869 – March 30, 1938) was a Russian and Soviet military engineer and inventor, creator of the world’s first submarine minelayer.
Born in Astrakhan, into the family of a white-collar worker he developed an interest in mechanics during his childhood, studied at the St. Petersburg Technological Institute, interrupted following his father’s death, forcing home to take charge of the family. He still passed examinations for a transport infrastructure technician as an external student. He travelled to Port Arthur to work on the construction of the port of Dalny (now Dalian, main PLAN shipyard and naval base). There, aside his job, he invented a bicycle with a unique design. Another hobby was making working models of submarines. In 1904, while in Port Arthur, he developed a submarine minelayer design already and funded it himself, writing:
The initial idea of arming a submarine with naval mines occurred to me on the day the battleship Petropavlovsk was lost (March 31) an event I witnessed after it exploded upon striking a Japanese mine. The destruction of two Japanese battleships on May 22 by our mines, laid off Port Arthur, further demonstrated the power of mine warfare and firmly cemented my conviction regarding the need for a new type of warship: the submarine minelayer. Such a vessel would make it possible to lay mines off enemy shores even when we did not command the sea.
That autumn, his “toy submarine”, just 25 tons, armed with four mines saw trials and dove at 9 meters. This was a relative success, albeit it lacked speed and range, obviously. Plus he had to leave it behind when the port city fell. It was scuttled. He was awarded the St. George Cross for his participation in the defense. In 1906, Naletov returned to St. Petersburg. He then developed a detailed design for a completely new type of submarine minelayer displacing 300 tons. In 1907, he created two additional variants of this new design displacing 450 and 470 tons. In 1907, he sent the final variant to the Naval Ministry. It was approved and funded in construction, this was the “Krab” (Crab), eventually laid in 1909 at Nikolaev.
However the minelaying system was geared for 60 mines and completion was delayed by years.
Following the October Revolution, Naletov worked as senior engineer in the Chief Mechanical Engineer’s department at the Kirov Plant, Petrograd until 1934. When Krab, scuttled by the British on the seabed of the Black Sea was raised in 1935, Naletov planned for its restoration and modernization. However, in between new models of submarine minelayers were developed in USSR. He died on March 30, 1938, today credited by all authors as the inventor of the minelaying submarine. Today all attack submarines -conventional or nuclear powered- have the capacity to carry mines and that tactic it still very much potent to block narrow waterways and harbour entrances, with the strait of Hormuz events in 2026 as a reminder.
Development of the Krab
So as we saw, Naletov had a design already in the works all the way back to the Russo-Japanese war, but lacking the facilities and creating his 25 tonnes prototype on his own volition and funding, it would have been barely able to mine the entrance of Port Arthur with its three mines. However, the number of technological challenges he had to resolve were a solid foundation for his future work. Back at St. Petersburg, close to the Navy HQ, he was willing to submit a much larger design, provided it can be funded. In 1906, this first design was presented to the Naval Technical Committee. It was of a much larger scale, at 300 tons. After addressing feedback, he designed two further variants, one displacing 450 tons and another 470 tons. These were large submarine, but not unheard of. In the same city’s yards, a US Lake design of four 482 tonnes (submerged) was already in construction with a planned launch in 1907. However, the Navy wanted more proposals and sent a tender to other yards. It seems Naletov, as brilliant he was as inventor had no background as naval engineer as his design needed deep revisions to be practical.
Construction at Nikoyaev
So by 1907, the Nikolaev Naval shipyard, Black Sea, submitted a 4th variant of the same minelayer to the Naval Ministry, for approval. In 1908, the Ministry awarded it contract to build the submarine minelayer. In the summer of 1909, after scores of model testing in the experimental pool, the shipyard submitted the final blueprints for its submarine minelayer. Along with new specifications, it was approved on July 11, 1909.
Hull assembly started by the end of 1909. Naletov was appointed as consultant for its construction. The submarine needed also adapted mines, and they were designed by Naletov. These models needed to have neutral buoyancy. He manufactured several prototypes to be tested. All this took years. At that stage, no other nation in the world has such submarine in the works. It was considered as a Russian “secret weapon” for a possible future war, and security was reinforced around the yard.
The name “Krab” was chosen, albeit it’s unclear why albeit at the time, all Russian submarines were named after marine animals anyway. The new submarine at last was started at the Nikolaev shipyard under supervision of engineer I. S. Kannegiser. Krab was launched on August 12, 1912, joining the Black Sea Fleet in 1915.
Legacy
However the time needed to have this design operational was damning as the Germans, which naval engineers sometimes worked with Russian ones on submarine designs, since the Forel (a German design sold to Russia) and other projects, might have knowledge at some point of this Russian “secret weapon” and started on their own program from 18 August 1914, ten days after the start of World War I. It was rejected at first, then relaunched after the success of the UB-I in November, leading to the UC-I ordered from Vulcan, Hamburg, built at a record pace in 5-6 months, with the first boats operational by 7 May 1915, two months before Krab (July)…
Krab remained the sole minelaying submarine operational in the Russian Navy for decades (the concept was rebooted in the interwar). Indeed, there were plans for more, many more, the B class (10) at Petrograd and Reval, the G class (28), V class (7) and Z class (4) all part of the 1916 submarine program. With the revolution none was completed, they were all cancelled. An evolution of the Krab design ranging from 230t (Z) to 971t (B) they were of mixed armament, with 75 mm deck guns in some case (B), ten torpedo tubes plus external ones in Drzewiecki drop collars, and ten mines in short tubes. The Z class ordered in 1916 were the only ones only armed with 20 mines. This paled in comparison of Krab’s 60 mines.
Even, the Germans never approached this figure, with the UC-II carrying 18 and UC-III only 14 mines, with their mine tubes placed in the ballasts in an oblique fashion, more a distant ancestor of modern SSBN’s missile tubes than the horizontal belt conveyor style tubes, perhaps more rational and inspired by minelaying ships, developed by the Russians. Both technologies were tested in the interwar by many nations. In any case, it’s still strange that Imperial Russia, being a pioneer in submarines as well as favoring mines as a primary weapon, did not pushed harder in time and resources to have submersible minelayers ready sooner and in number. Let’s blame here naval conservatism. in the naval staff They would definitively have an impact in the Baltic, potentially able to stop all naval advance by the Germans well before the gulf of Finland, supporting their land advance.
Design of Krab
Hull and general design
Krab was a single-hulled boat displacing 512 metric tons (504 long tons) surfaced, 722 t (711 long tons) submerged. This made her the largest submarine design of 1912. Her overall length of 52.73 meters (173 ft), for a beam of 4.33 meters (14 ft 2 in), draught of 3.96 meters (13 ft). The ballasts were internal. She had no blisters or bulges. As for the hull design, it featured a ram bow, unique to Russian submarines at the time, reinforced and usable in practice for this, the hull was narrow forward but had a constant beam over most of its length, dictated by the presence of the horizontal mine tubes for most of her length. The poop was rounded and broad, with a downwards slope with external guide rails for the mine chutes.
She also had an amidship conning tower, with a fairing for two periscopes (as shown in the model), and hatch, and two other hatches fore and aft. She had a small external helsmman’s post in fron the the CT fairing, and another base fairing about 7 meters long around. Outer steps were later added to allow walking around. There was a tall dorade box to draw air for her engines aft, but it’s unknown if it can be folded down when underwater to reduce drag. There was also a telescopic signal mast forward, but no apparent radio. There was a large hatch and a couple of crane forward to reload the mines. The model also shows two more dorade boxes on top of the CT fairing, but only one is shown on photos, immediately aft of the CT. She also had apparently a small 30 cm diameter searchlight. Her crew amounted to 53 officers and crewmen: 3 senior officers, 2 warrant officers and 24 ratings.
Powerplant
When surfaced, Krab run on four gasoline engines, each propeller shaft (bronze 3-bladed fixed pitch, diameter unknown) having one driving pair. They produced a total of 1,200 brake horsepower (1,217 PS; 895 kW). Design speed was an honorable 11.8 knots (21.9 km/h; 13.6 mph). When submerged, the shaft were recoupled with electric motors, rated for 330-brake-horsepower (335 PS; 246 kW). In that case, top speed was 7.1 knots (13.1 km/h; 8.2 mph). The surface endurance was 1,700 nautical miles (3,100 km; 2,000 mi) at 8.6 knots (15.9 km/h; 9.9 mph), 82 nmi (152 km; 94 mi) at 4.13 knots (7.65 km/h; 4.75 mph) while submerged.
Krab also had a diving depth of 50 m (160 ft), 37 meters in service.
There were two forward underwater diving planes, and two more aft close to the tail (single rudder). Russian sources gives more figures, with a max speed of 10.8 nm surfaced and 8.3–8.6 knots sumerged on trials, and on economical mode, 8.5 knots surfaced and 5.5–5.9 knots submerged was ideal. Surfaced, the max range would be up to 2000 nm at 8.5 knots, 1,200 at 10.8 knots. Underwater range could be up to 138 miles at 5.9 knots. Fuel capacity was only 13.5 tons of kerosene. Krab had a diving time of 7 min 38 sec. and a surfacing time of 4 min, and a reserve buoyancy of 14%. No doubt that she had extra ballasts to compensate the laying of all 60 mines that considerably reduced her top weight to stay balanced underwater.
Armament
Krab was not armed exclusively with mines. She had four 450-millimeter (17.7 in) torpedoes for self defence: Two were in internal bow tubes, technically reloadable albeit there was no space for spares, and two more in external rotating Drzewiecki drop collars, one per broadside. However, the latter never appears on any photo. However her main striking force was her sixty PL-100 mines, housed in two horizontal tunnels, above the pressure hull, below the deck. The mines were laid through the stern, using an electrically powered chain conveyor designed by Naletov and refined by Nikolayev engineers. There were fittings on deck also for a standard 75 mm (3 in) deck gun plus two 7.62 mm (0.300 in) machine guns in 1916, but again, they seems to be absent from early photos and likely installed later in 1915-16 as they were present on the wreck when rediscovered in 1934. Navypedia instead states she had a 37mm/20 Hotchkiss. The machine guns were 7.6mm/94 maxims for AA defence.
⚙ specifications |
|
| Displacement | 512 long tons (520 t) surfaced, 722 long tons (734 t) submerged |
| Dimensions | 52.73 x 4.33 x 3.96m (173 ft x 14 ft 2 in x 13 ft) |
| Propulsion | 2 shafts 4 gas. engines 1,200 bhp, 2 EM 660 bhp |
| Speed | 11.8 knots surfaced, 7.1 knots submerged |
| Range | 1,700 nmi/8.6 knots surfaced, 82 nmi/4.13 knots submerged |
| Armament | 4 torpedoes, 1x 75mm deck gun, 2 MGs, 60 mines |
| Max depth | 50 m (160 ft) |
| Crew | 53 |
Career of Krab
Construction was already delayed due to the design of her the ballast tanks, which had to be redone entirely and res-tested, and eventually she was launched on 19 August 1912. Hee first captain for her fitting out was from 7 (20) November 1912 to 12 (26) May 1913 Senior Lieutenant Andreev, Alexey Alekseevich. Then from 13 (26) May 1913 to 2 (15) September 1914 Captain 2 rank Bykov, Boris Alexandrovich. Krab performed her first diving test on 22 June 1913. She proved to be unstable and was immediately back to the dockyard to be weighted down by no less than 28 t (28 long tons) lead into her keel. This modification was completed in the autumn of 1914. More tests lasted until July 1915, and she was finally commissioned on 25 June 1915. From there to 10.08.1915 Captain 2 rank Fenshaw, Lev Konstantinovich. From 10 August 1915 until 01 July 1917 as she became at last operational and fully commissioned, Senior Lieutenant Parutsky, Mikhail Vasilyevich.
She was naturally assigned to the Black Sea Fleet, too large to be sent back to the Baltic where she might have been more useful.
During her service, Krab carried out two underwater minelaying missions in the Bosphorus Strait: The first on June 27, 1916, and another at the entrance to the port of Varna. It is confirmed that the Turkish gunboat Isa-Reis struck a mine but was only damaged. There is a theory that the German cruiser Breslau also struck mines laid by the Krab however, naval historians now believed they had been laid by Russian destroyers, as the site of the explosion was at a considerable distance from the Krab’s own logged minefield.
In 1917, Krab underwent repairs an engine replacement. The electric motors, gasoline engines, battery ventilation fans were sent to Kharkiv for major overhauls. The four kerosene engines were replaced by two new, modern 480 hp diesel engines from unbuilt AG-class submarines shipped to Mykolaiv disassembled. They were part of the final series with AG-26 equipped with diesel engines having only 1/4 of the standard power output. This much delayed the return of Krab in active service. In fact she never made another minelaying mission. After the 1917 Octbober revolution, experiences naval officers able to command Krab fled or were executed. There was no plan to use her anyway.
In 1918, Krab fell into the hands of German forces and the Entente naval command. In April 1919, she was scuttled in Sevastopol’s North Bay by her new British owners to prevent her falling into the hands of the advancing Reds. To sink her, a 0.5 m² hole was drilled into her port side near the conning tower, plus the massive reloading bow hatch was opened. She sank and remained on the bottom for four years, degrading fast. By late 1923, the rescue organization EPRON was established to salvage all scuttled ships in shallow waters during the civil war for restoration. This became Russia’s primary organization for ship salvage operations. In 1934, while searching for sunken submarines, a metal detector registered a large mass at a specific location and divers were sent there. They identified the wreck as the submarine Krab. She layed under 65 meters, below her max depth, but her pressure hull, filled, had resisted while her stern was deeply embedded in the seabed. There was the scuttling breach on the port side, though the gun and periscopes remained intact.
Salvage operations started by the summer of 1935. it was decided to raise her in stages, gradually bringing her to shallower depths. Initial attempts in June failed to break the stern free from the seabed. So divers went down with hoses and pumps to clear away sediment around the stern. The swell threatened operations and the great depth limited divers to 30 minutes tours. Nevertheless, this first phase was completed by October and on October 4-7, three successive lifting stages were carried out after which she emerged, and was towed back to port.
Krab’s inventor, Mikhail Petrovich Naletov, meanwhile had retired a year before she was raised. He was living in Leningrad at that time. Upon learning it, he he drafted a plan for her restoration and even modernization. But the Soviet Navy by the time had many, more sophisticated minelaying submarines. Even the work of preservation was denied and deemed unnecessary. She ended in scrap metal.
Read More/Src
Books
Apalkov, Yu. V. (1996). Combat Ships of the Russian Fleet: 8.1914-10.1917.
Breyer, Siegfried (1992). Soviet Warship Development: Volume 1: 1917–1937. Conway Maritime Press.
Budzbon, Przemysław (1985). “Russia”. In Gray, Randal (ed.). Conway’s All the World’s Fighting Ships 1906–1921. NIP
Polmar, Norman & Noot, Jurrien (1991). Submarines of the Russian and Soviet Navies, 1718–1990. NIP
Saxe, Ronny (2008). Geschiedenis van de Onderzeeboot [History of the submarine] (in Dutch). Tielt: Lannoo.
Links
rusdarpa.ru
web.archive.org navypedia.org
web.archive.org ukonline.co.uk/
web.archive.org/ morflot.tsi.ru/
web.archive.org flot.sevastopol.info/
ru.wikipedia.org/
Russian_submarine_Krab_(1912)