Category: WW2 Soviet Naval Aviation

The Tupolev Saga

For that introductory matter into Soviet naval air power, it is important to stress the importance of Andrei Tupolev, not only for the development of bombers, to put in parrallel to Boeing, but in aviation in general. His models, taking the best innovations of its time, record-breaking when seen, proved extremely durable as well. Russia was no foreign to massive aviation, with the Ilya Murometz of genius designer Igor Sikorky, later immigrant to the US during the revolution and creator there of a most famous Helicopter lineage. And so several names will soon associate themselves with the birth of Soviet heavy aviation, like Sergei Ilyushin and Vladimir Myasishchev, like Andrei Tupolev from TsAGI.

This story starts naturally with Andrei Nikolayevich Tupolev, born on 10 November 1888 in Pustomazovo, near Kimry (Tver Governorate in the Russian Empire). His father worked as a notary for the governorate so he was no illeterate and received a good education and had abilities, confirmed when he studied law at St. Petersburg University. Allegedly linked to Alexander II’s murder as an alleged revolutionary he was expelled and worked at Gymnasium in Tver 1908, then studied at the Imperial Moscow Technical School (IMTU) and Emperor Nicholas II Moscow State University of Railway Engineering, being accepted at both but only attending IMTU. Next year he specialized in aerodynamics under Nikolay Zhukovsky, volunteering at the Aeronautical workshop and by 1910 with his workshop friends her built and test piloted his first glider.

Her later created the first wind tunnel in Russian and started the first aerodynamic laboratory at IMTU. In 1911, he was accused of revolutionary activities and arrested but released on condition he returne to his family at Pustomazovo. In 1914 however Russia needed all the help from its engineers for its growing aviation and Andrei was back to IMTU in 1914. He continued in his field until 1917, and through the Russian Revolution, being graduated in 1918 as Engineer-Mechanic and presented his thesis on the development of seaplanes. By 1920 IMTU became the Moscow Higher Technical School (MVTU) and Andrei became a teacher, on basics of aerodynamic calculations.

A central figure in Russian Aeronautics, Tupolev became a leading fugure of the Central Aerohydrodynamic Institute (TsAGI) from 1929 until his death in 1972, including as director. In the 1930s-era his designs were based partially on all-metal aircraft design concepts pioneered by Hugo Junkers and by 1925, he designed the first modern Soviet twin-engine bomber: The TB-1, one of the most advanced designs of the time, that we are seeing here. Tupolev lso designed “monsters” like the 63-meter wingspan eight-engined Maksim Gorki, and the four-engine TB-3, still the bedrock of Soviet Bomber units in 1941. In 1937, 21 October he was arrested together with Vladimir Petlyakov and the entire directorate of the TsAGI by Stakin during the great purges. In 1939 he was moved from a prison to an NKVD sharashka to continue working under strict surveillance and released in July 1941 after making his unit the “Tupolevka” and designing the esxcellent TU-2.

Long story short, he will continue development of various models but really shone post-WW2 with a serie of large bombers, piston-powered and reactor-powered, including many used for naval patrol and reconnaissance and attack. His contribution to aviation worldwide until 1972 is just colossal, and he had state funerals.

The first moden Soviet Torpedo Floatplane

The TB-1P was a mere variant of a famous bomber, the TB-1, still flying in 1941. The story of this model started in 1924, when TsAGI, managed by Tupolev, started a prototype under the development name ANT-4, as a two-engine modern bomber aircraft. It used a technique aquired from Junkers 1918, the corrugated Duralumin skin to get rid of framing and still procure great rigidity. It was a very sturdy, angular monoplane which became the backbone of the Soviet bomber force for many years: Its first First flight was on 26 November 1925 and it was introducted to the VVS in 1929 (used also by Aeroflot) and produced until 1932, until 66 extra models of the last batch were kept for conversion as floatplane bombers. Its durability was amazing, and the TB-1 was still in numbers when the German invasion started in 1941, as the transport model G-1. In fact it was only retired in 1948. Its drivative was the R-1 reoconaissance model and of course the quad-engine TB-3. Of course the TB-1 became a landmark as the first large all-metal aircraft built in the Soviet Union.

Initial development

Back in December 1925, the main aviation bureau offered TsAGI to take over the construction of a “sea bomber”. This was to be a large flying boat. A first for TsAGI at this scale as it lacked a proper water pool to test models. It was risky to take on that one, and instead internally it was voted to ope for the safer way, installing floats on an existing, proven land aircraft, which brought many advantaged with it. Only calculations linked to the drag caused by the floats, and weight repartition, were to be a concern for modifications. On January 15, 1926, a letter was received from the OTB to make preliminary calculations for a float-based ANT-4 (factory name for the Tu-1). Delays however had the project falling under schedule. At the start of 1928, the UVVS required a conversion of the TU-1 on floats as soon as possible. Calculations were also reworked to integrate the installation of brand new BMW VI engines to compênsate for the drag and added weight of the floats. Their types was not specified so the team opted for the simple solution of having two main underwing floats, leaving free the belly section for payloads. In December data from TsAGI was senet to the UVVS for evaluation on paper.

In September 1929, the UVVS came back to TsAGI confirming the choice of a serial Tu-1 in marine version and this time precised the recommended type of floats. On October 11, TsAGI proposed the same type used by Junkers on their the Marine Ju-1 prototype, with some forward alteration. The institute refused new floats and by October 30, UVVS decided to order to Short in UK a new floats chassis. They were indeed urgently needed for a propaganda flight to America. These floats were manufactured at plant No. 22 and tested in Taganrog, mounted on a cradle in a basin. This was successful. Then, they were mounted in a specially modified plan, which crashed as the propeller blade collapsed. Quickly repaired this prototype became the propaganda plan “Country of the Soviets”, brightly colored, which successfully completed its intended trip overseas.

In the meantime, Short sold the the intended final floats pair, more suitable for the larger TU-1. They were slightly larger, with a fuller outline. In April 1931, a single modified TB-1 was transferred to Taganrog, and in three months the floats were assembled and first tests performed, with transfer on June 15, to the naval department of the Air Force Research Institute for official tests in Sevastopol, until the end of August. This model became the TB-1a in Soviet Ordnance (“a” standing from “aqua” in latin or “water”).

The additional floats and the drag they caused was a concern to find the right engine power. Maximum speed did not exceed 185 kph on the initial tests and ceiling was limited to a mere 3,620 m (). Maneuverability and rate of climb were also far inferior to the TB-1. However, given the overall package, it still carried the same heavy payload. It was thus considered satisfactory. Compared to the Junker YuG-1 and Val in naval squadrons, the TB-1a was better suite for anti-ship missions. This, the TB-1P was adopted by the Red Army Air Force.

Production in Taganrog

Mass production of floats was organized, with English measurements converted and drawings made. Factory No. 22 was first contacted, but already overloaded and so documentation and sample floats were transported to Taganrog to be manufactured as the “type Zh”, installed also on TB-1 arriving from Moscow’s main Tupolev plant.

A possible evolution: The TOM-1

Basically the “production” of the TB-1P was carried out after the cessation of production of the TB-1 back in Moskow, most arriving models being mothballed. A total of 66 underwent this conversion at Taganrog, being eventually called TB-1P and sometimes MTB-1. However to reach a greater production with a more perennial model, it was also necessary to study an evolution, the TOM-1. This aircraft in developement since August 1928 by design bureau (Plant 28) under guidance of the engineer P. Richard from France. It was close to the TB-1P, but larger, heavier and with a stressed smotth skin rather than the original corrugated surface, inherited from Junkers designs. The TOM-1 prototype was built and tested in December 1931, and although significantly superior, it was abandoned on the ground of technological complexity and high cost.

General conception

The TB-1P was essentualy a TB-1 with floats, used as a torpedo bomber. The original base was also the first Soviet all-metal heavy bomber, quite a milestone. Most of the work consisted in nailing the right type of floats until the Short type was eventualy adopted. Conversion was was transferred to Taganrog and it took three months to assemble and install the floats. Tests were validated by August 1931.
So the “design” of the TB-1P was essentially to find ways to combat extra weight and additional aerodynamic drag induced by the floats. Maximum speed at first was not impressive, as the ceiling, and climb rate deteriorated, but still, it had the required payload for its mission. The TB-1P inherited the same corrugated duralumin fuselage, which dispensed of framing but ion a limited parts, notably the wing-support chassis. Quite crude, the TB-1 had no enclosed cockpit, but a glassed undernose for the observer. The pilot and copilot at the front were in open air and had to shout to communicate. Defensive armament was good, with a nose and two dorsal turrets with twin flexible mounts and light Machine guns. Command used cables and the tail surfaces were compensated and balanced.

The “type Zh” floats were basically copied of the Short model. They were all-metal in duralumin, attached by “N” type struts under the wings, below the engine attachement points and with cross bars, close to the fuselage underside. They had hatches in order to store a flexible lift raft, and survival kits or rations, and had hooks to be towed. Two ladders allowed to communicate with them, on either side of the fuselaged, with the crew walking on the wings.

Engines

The Mikulin M-17 was a Soviet-licensed copy of the German BMW VI V-12 liquid-cooled aircraft piston engine. Alexander Mikulin improved the output and simplified it, to be used by Soviet aircraft and tanks up to World War II. Production started in 1930, up to 1942 with 27,000 produced, 19,000 being aircraft engines and the rest in the BT-7, T-28, T-35 and KV-1.
Type: 12-cylinder 60° Vee aircraft piston engine, bore 160mm (6.30 in)
Stroke: 190/199 mm (7.48/7.83 in) different between right and left cylinder bank due to articulated connecting rods.
Displacement: 46.9 L (2,864 cuin)
Length: 1,810mm (71.26 in)
Width: 859mm (33.82 in)
Height: 1,103mm (43.43 in)
Dry weight: 540-553 kg (1,190-1,219lb)
Fuel system: K-17 Carburetor
Cooling system: Liquid-cooled
Power output: 680–730 hp (510–540 kW) but 510 kW (680 hp) each on the TB-1 as it was the first generation.
Compression ratio: 6.0:1 or 7.3:1

Armament

It consisted of six Degtyaryov standard DP-27/DP-28, 7.62 mm light machine guns, the standard used by infantry at the time. They were all given drum-like 47 rounds cartridges boxes, with tracers. These were Gas-Operated with flapper locking, had a rate of fire of 550 rpm and muzzle velocity of 840 m/s (2,755 ft/s), but effective range was just 800 m (874.9 yd). To compensate, twin mounts were installed, but against modern fighers of the 1940s, they were hopeless.

The main reason these models were designed, were their offensive payload. It could be triple:
-BOMBS: Standard 250 kgs, or 50 kgs incendiary bombs up to 1000 kgs so four 250 kgs for example, in the enclosed bomb bay.
-Torpedoes: In 1931, the Soviet Naval Aviation were classed as TAN “Torpeda Aviatsionnaya Nizkaya” (Torpedo, Aircraft, Low Altitude), VVS-12 torpedo and 450 mm (17.7″) TAN-12 Powered by a Wet-heater and based on the 45-12 (456 mm Pattern 1912) torpedo.
Mines: Several types were used, but the MAV-1 was the most common. Each plane could only carry one of these, which was a moored underwater mine, self-deploying at a setting made before the flight.

Specifications TB-1P
Crew:	6: Pilot, copilot, observer/bomber, 3 gunners
Dimensions:	18.00 m, Width: 28.7 m, Height: 5.10 m
Weight: Light	Unladen 4,520 kg, Max. Combat: 6,810 kg
Propulsion:	2× M-17 V-12 liquid-cooled engine | 680 hp
Performances:	Top speed: 178 kph Service ceiling: 4,830 m
Endurance:	1000 km range
Armament – MGs	6x 7.62mm DA MGs
Armament – Bombs	1000 kgs, or a 18-in torpedo, or a mine

Service

Early units

Since the TB-1 was originally designed for experiments with aircraft mines and torpedoes, it was quite logical to transfer some of these machines to naval aviation. The first mine-torpedo unit started before even May 1931, and the Air Force Research Institute proposed to create a “torpedo cell” as part of the 9th air brigade, Black Sea. One TB-1 was transferred from May 25. It validated the creation of a torpedo detachment commanded by the pilot Morozov, based in Kutch but equipped with land-based TB-1s equipped with a universal OTB belly carriage to suspend the VVS-15 high-altitude torpedo and VOMIZA-100 mines with similar parachute systems, using several domes to gradually damp the fall speed; They also used VVS-12 torpedoes from low altitude flight.

Tests of mines and torpedoes started in March 1932. By September, they started to use them on live targets like the old battleship “Pariskaya Kommuna”. In October fleet maneuvers saw TB-1s dropping torpedoes on a target 15 miles from the Chersonese lighthouse, missing due to the drift of parachutes with the wind. Until November 14, nine drops were completed. Next, the unit received its first TB-1P floatplanes, and by the end of September 1931, the 62nd Squadron (4th Aviation Brigade) had three YuG-1s, three TB-1Ps in the Baltic, testing the VVS-12 torpedo, entering service as the TAN-12, while a high altitude (parachute) one was called the VVS-15, later TAV-15 in service. The parachuted mine VOMIZA-100 became MAV-1 and modernized in 1933, lightened and simplified.

The same year, the TAV-12 became standard as an aerial torpedo, stronger than the TAV-15 as it could be dropped at 180 km/h, with higher speed and thrice the range. In 1934-1936 the TAN-12A was improved with a parachute system reduced to 120 kg and 45 s descent time, followed by the TAV-15A. Meanwhile were created the 121st Squadron in the Baltic and 124th Squadron in the Black Sea, 1st Squadron in the Pacific, which 12 TB-1/4Ps each according to registers. Each was divided into three flights of four planes, same type (eiher TB1 or TB-1P). By March 1932, the 51st squadron from Voronezh was transferred to Khabarovsk in the far east, joining the 1st Squadron. But torpedoes and mines were lacking.

Deployment and tactics

High-altitude torpedo drops were certified in the 1st squadron (Pacific) in the spring of 1933. At the time, these units were supposed to lay active defensive minefield directly in the path of incoming naval units. These dynamic barriers would appear unregistred in the most unexpected spots in a matter of hours. They were setup by groups of four planes in succession, in three waves. Distance for the drop were measured with a special rangefinder designed by A.E. Stolyarsky, aimed with the SP-123 sight while was promised a telemechanical (radio-controlled) system used by the lead aircraft (it was never adopted).
It was however sometimes difficult to find the correct spot based on map information, so it was though of dropping mines directly in the path of a moving ship, a dangerous task. It was later theorize it could force the ship to maneuver out oits path, crssing an attack of torpedo bombers or torpedo boats. This was taken seriously by the Air Force Research Institute and the tactic was tested in October 1933, held in the Baltic and directed by the head of the Red Army Air Force Ya.I. Alksnis. TB-1Ps of the 121st squadron used TAN-12 torpedoes and MAV-1 mines in a coordinated attack on a moving target, the old destroyer Karl Marx maskeraded as the Finnish battleship Vainemäinen. The strike also comprised masking smoke curtains S-62B and implicated R-5 light bombers to deal with AA with small bombs and strafing fire. A mine line was laid on her path, constrain its maneuver, allowing a flanking torpedo attack. But it failed:

The destroyer left the minefield ten minutes before the TB-1Ps appeared and it was too late while Mines were laid not on her course but to her left. Torpedo bombers attacked in two pairs, from the north and south under the cover of smoke screens and made an impression still. However the northern one appeared too late and too high. Still, the south group manage to hit the ship with a torpedo. On October 15, the exercize was repeated on the larger battleship “Marat”. The P-5 bombing was successful with one direct hit. This experience proved this “dynamic minelaying” was not realistic as a tactic, and this use of the MAV-1 was found inappropriate, although still promising.

Late Interwar service

It was recommended to continue combined operations with MAV-1 mines and TAN-12 equipped TB-1Ps, using smoke curtains to masking their manoeuvers. In June 1934 during the summer maneuvers of the Baltic Fleet 12 aircraft were used against Marat, attacking from different directions with TAEM 5 training torpedoes. Several hits were recorded, but iot was a high-altitude drop, not very successful overall. Meanwhile, Low altitude torpedoes were considered purely offensive, with aiming carried out using primitive rack-and-pinion sights for the lead plane. KP-2 sights were installed and later replaced by the PT-136 with an optical rangefinder and vector mechanism taking account of relative speeds. The Yeysk school by January 1935 had 26 TB1s for naval air bombing training.
On October 4, 1933, the Chief of Staff of the Air Force wanted to expand operations with ten squadrons (four with TB-1s) and by December eight squadrons were formed, almost a for the Far East, but this was never realized.
The TB-1P were actively used in the Baltic, but mostly as scouts-bombers. There were not enough mines and torpedoes for training. In winter, skis were installed, or wheels. In September 1934, the 122nd squadron took part in the lost submersible L-2 “Stalinets” in the Gulf of Finland. She was found and part of the crew, all the wounded were evacuated by the squadron commander A.M. Viraka.
In September 1, 1936, six squadrons of TB-1Ps operated in the Soviet mine and torpedo aviation unit, four TB-1s, two in the Baltic Fleet (121st and 122nd) plus one incomplete, the 34th in the Black Sea, and the 109th in the Pacific fleet. The latter was re-equipped with TB-3s. 12 aircraft were at the Yeisk flight school.

In the next two years, The 34th squadron in Evpatoria had its TB-1Ps replaced with the new R-5T. On January 1, 1938, still 38 TB-1 and TB-1P were active in several naval combat units. However it was ordered to retired them, to be sent to auxiliary units or scrapped. By September 25, 1940, there were still 14 TB-1s active, and just six were flyable, used for training purposes and transportation.

Gallery

Author’s illustrations: Types and liveries

Basic Tupolev ANT-4 of a coastal bomber unit in 1934. It was replaced by the TB-2 rapidly.

TB-1P in the Baltic Fleet, 1933. Most of these were used for reconnaissance until 1937.

TB-1P carrying a single TAN-12 torpedo, 62nd air brigade, Baltic Fleet, Leningrad, Summer 1934.

TB-1P carrying a MAV-1 mine

Additional photos

Resources

Aviation collection. V. Rigmant, V. Kotelnikov. Heavy bomber TB-1
Maximilian Saukke. Tupolev aircraft. ANT-1 – ANT-15
G.F. Petrov. Seaplanes and ekranoplanes of Russia 1910-1999
Shavrov V.B. History of aircraft designs in the USSR until 1938
Simakov B.L. Aircraft of the country of the Soviets. 1917-1970
Encyclopedia-reference book. Aircraft of the country of the Soviets
Vladimir Rigmat. Under the signs “ANT” and “TU”
SAE Int. Paul Duffy, Andrei Kandalov. Tupolev: The man and his aircraft
OAO “Tupolev” : From ANT-1 to Tu-334

Links

navweaps.com soviet interwar aerial torpedoes
On airwar.ru
On airpages.ru

Videos

Soviet torpedo bomber Tupolev TB-1P (1930s) Aviation videos archives part1 1900-1935
The Soviet Bomber That Was Utterly Bonkers | Tupolev TB-3 – Rex hangar

The model corner

On scalemates, Mikromir
kit review of the latter.

An amazingly long success story

The Shavrov SH-2, affectionately called “Shavrushka”, shares with the Polikarpov U-2 and Antonov An-2 the title of longest serving biplane in aviation history. But she was the only one being tailored as a seaplane, abeit amphibious. He production numbers never reached the scale of the others two but was remarkably long. Anyway, she rendered immense services to the VVS and the Soviet Navy and Air Forces at large, the coast guards and Aeroflot during the interwar and WW2; Some even fought on the Finnish side. Her key assets were her immense sturdiness and a simple and robust engine that lasted decades.

About Shavrov

The latter is not the most famous Russian designer ever, but leaving a mark nonetheless in the aviation landscape for a few years, by designing mostly seaplanes. Vadim Borisovich Shavrov was born October 26 (November 7) 1898 in Moscow, and became an aircraft designer after the civil war. He had his PhD many years after, in 1945, as aviation historian. Outside designing flying boats he redacted a two-volume monograph History of Aircraft Design in the USSR.

Born from an artillery officer in 1914 he entered the St. Petersburg Institute of Railway Engineers. In the Civil War, he worked on topographic expeditions in the Volga region and the North Caucasus. He later returned to the institute’s new aviation department and after graduation as appointed to the Russian Voluntary Air Fleet Society (“Dobrolet”) as deputy head of the Central Asian lines. By 1925, her worked for the Department of Marine Pilot Aircraft Construction, Krasny Pilot Plant (Aviatrest) by then headed by D. P. Grigorovich (Leningrad, Krasny Pilot plant).

But aside his team work, Shavrov worked on the ROM-1 flying boat. In 1926-27, teaming with V. L. Korvin her joined a small team woking on spare hours on a design later reviewed by the Osoaviakhim, receiving support. The summer of 1929 saw the SH-1 prototype followed by the Sh-2 flying boat reaching production, under supervision of Shavrov alone, hence the name given for the model. Next, he would create the SH-3 to Sh-7 (the latter as a planned replacement in 1940) but they all stayed at prototype stage, leaving the SH-2 his only production model.

In 1955 Shavrov took the head of the design department of OKB-256 under P. V. Tsybin, taking part in the RGSR supersonic seaplane project while studying history of aviation, publishing a massive 3-volumes work and by 1968 had a cameo role as pilot in the film “Two Comrades Were Serving” and apssed out in 1976, buried in the prestigious Donskoy cemetery.

The Shavrov SH-1 (1929)

Starting in 1925, development of “hydroaviation” started in Russia (which already had a sizeable naval aviation well before that). The term ‘hydro’ was coined by the French in 1912 from the Greek “water” was used as “idro” in Spanish and Italian – In the anglo-saxon world those which featured a boat-like fuselage were called “flying boat” or simply “sea boats” and those convertible from standard undercarriage to floats were called “floatplanes”.

The USSR carried out researches at the Department of Marine Experimental Aircraft Construction (OMOS), Central Design Bureau in the complex Aviatrest in Leningrad. The “workshop” was the entire Krasny Pilotchik plant (“red pilot factory”), under the direction of D. P. Grigorovich. and V. B. Shavrov in the design team, mostly working on a STOVL prototype.

In a private conversation in early 1926 with his old acquaintance V. L. Korvin-Kerber the idea emerged of the need of a reconnaissance aircraft for polar aviation, an amphibian which could operate on ice from even a small ship and have an extremely short takeoff run. This plane simply did not existed at the time. Shavrov was interested by the challenge, and joined the small team working on it in his spare hours, at Korvin’s appartment.

By the fall of 1926, the draft was ready, dhowing a two-seat parasol sesquiplane (large top wing, half wings below attached to the fuselage) flying boat, of wooden construction and propelled by a 40 hp engine mounted above the wing, out of water spray. It was known underpowered at the time and a Soviet 60 hp engine was in development for it in the long run.

In 1928, OMOS was transferred to Moscow and Shavrov managed to present his project (Korvin was jailed at that time) to the technical council of Osoaviakhim, impressed by it and funding a propotype with 4,000 rubles. All the main components and assemblies were made in Korvin’s Leningrad apartment, third floor. Despite the working conditions, development was carried out quickly. After initial wind tunnel tests showed no major issue, the Sh-1 was handed over to Osoaviakhim for a first flight test on 21 June 1929, performing well by topping 126 kmph from her puny 63 kW Walter radial engine, promising even better performances with the new engine on development. The Osoaviakhim used this prototype for propaganda flights painted in bright colors. On February 26, 1930, V.P. Chkalov and mechanic Ivanov crashed in bad weather, and the SH-1 was not restored.

The polar amphibian was not Shavrov’s idea

The Aviette SK (1926) on which Shavrov worked with A. N. Sedelnikov, V. L. Korvin-Kerber at the Red Pilot Factory.

On the above, before the SH-1, Shavrov worked with the tacit consent of D. P. Grigorovich in his free time with A. N. Sedelnikov, V. L. Korvin-Kerber in the spring of 1926 on the “SK”, fitted eventually with a 16 hp Harley engine was wonderfully shaped monocoque fuselage glued from 1.5 mm plywood. It could perform super-slow takeoff and landings at 45 kph and had very desirable flight qualities despite a very weak engine. Shavrov was interested by STOVL at the time.

For the anecdote, it’s B. G. Chukhnovsky which first expressed the idea of polar aviation and ice reconnaissance which needed a dedicated a model taking off/landing on ice and water indifferently. In the autumn of 1926 with P. D. Samsonov, V. L. Korvin-Kerber they visited Sevastopol to examine the all-metal Dornier Wal just acquired by the Air Force showed its extreme ruggedness and that it could indeed serve in the Arctic. V. L. Korvin-Kerber saw the drawings of another flying boat by German company Libell, even more attractive with its small aircraft project.

Back to Leningrad, together with B. G. Chukhnovsky, they decided they could create the amphibious aircraft of the Libell design but using solutions from the “Wal”. B. G. Chukhnovsky promised he would secure approval and funding from Aviakhim, where he was well acquainted.

Almost immediately, V. L. Korvin-Kerber started work and at the time, a young OMOS employee, V. B. Shavrov was invited. In fact it’s him that brought on the table some useful connections in the aviation industry. V. B. Shavrov was still working at Red Pilot for a few months, but managed to acquire his sjill designing the monocoque fuselage of the ROM-1 flying boat, and it showed it. Like the previous SK, the flying boat was designed in free time, from the end of 1926, until the summer of 1927. It was a wooden hydroplane (an abundant material in Russia), and the very first soviet/Russian amphibian.

Design and construction

The SH1 “polar bird” wooden mockup presented in 1928 to secure funds

The SH-1 (the name Shavrov was attributed later as it was created at Shavrov’s own appartment) distinctive feature was a pulling configuration (propeller forward) was used, in contrast to the usual “pushers” flying boats of the time. It was a strut-braced “polutoraplan” (sesquiplane) with a lower cantilever wings-floats (the latter were integrated in it) at the waterline. It gave extra lateral stability on water. The aerodynamic features of the wings achieved a maximum lift coefficient at a small inclination angle when hitting water or land. Additional lift was created by floats. These recipe were borrowed from the Libelle design.

In the summer of 1927, a first wooden mockup model was presented at the Polytechnic Institute and thanks to Academician A.N. Krylov, back from Great Britain, he presented the project to the direction at Osoaviakhim.
But circumstances have changed at the time. By the autumn of 1927, D. P. Grigorovich sent V. L. Korvin-Kerber on a business trip to Sevastopol, tasked to test the ROM-1 as open sea reconnaissance aircraft. Her was still there in the spring of 1928.

Meanwhile OMOS moved from Leningrad to Moscow and due to disagreement with chief designer Grigorovitch, many key employees left his department, but V. B. Shavrov paradoxically, who disliked hom as well, was the only one sticking with him. By early April with full support of B. G. Chukhnovsky, V. B. Shavrov presented his project to Osoaviakhim, who approved it (and thus allocated his name and not “Korvin-Kerber”). V. L. Korvin-Kerber would later return t help him with the Mechanic N. N. Funtikov to care for the engine and dahsboard.

The Sh-1 propeller preserved in the family of one of its authors, V. L. Korvin-Kerber, after his death in 1930.

Construction started on April 14, 1928 and the wooden fuselage and wings were all strapped into fabric tailored by V. L. Korvin-Kerber’s own wife, Yulia. It fell well in the calender as the Leningrad branch of the Aeroarctic International Society just obtained a study in the far north in the new five-year plan. In August, parts were lowered through the window of the third floor into the courtyard. it was assembled there and prepared for taxiing in front of the Malaya Nevka block. The pilot chosen was L. I. Giks. However on November 5, VL Korvin-Kerber was arrested 2 months D. P. Grigorovich own (false) accusation of sabotage. Their cases were combined but the “Shakhtinsky case” eventually died down due to the lack of proofs. By the end of 1929, they were working at the first aviation “sharaga” in the Central Design Bureau 39 Menzhinsky OGPU.

Design changes for SH-2 production

Left alone, V. B. Shavrov dismantled the plane, transported in the hangar of the test airfield and it was reassembled the next summer, to be tested at sea. On August 31, 1929, pilot B.V. Glagolev and mechanic N.N. Funtikov flew with it to Moscow, taking off from the Neva and after 5 hours, 30 minutes, landed at the Central airfield. It was tested there at the Air Force Research Institute by a commission headed by Air Force Research Institute P.I. Baranov assisted by pilots B.V. Glagolev, M.P. Korovkin and A.V. Chekarev. For production they were all agreeing on a radical increase of the engine power, from 85 to 100 hp. The commission also recommended that the center of gravity was reclaculated due to the new planned engine; The name Sh-2 was attributed.

Aircraft designer A. S. Moskalev observed the work of V. B. Shavrov and was very impressed by him, not knowing the full story behind the model. V. B. Shavrov postponed the construction of the production prototype for a whole year, and convenientely “forgot” about V. L. Korvin-Kerber, but it was recoignised 40 years later in his two-volume book History of Aircraft Designs in the USSR. At the time he distanced himself from an “enemy of the people” and saved the project. In an ironic twist, Viktor Lvovich Korvin-Kerber’s appartment was later unexpectedly rewarded as a “House of Specialists” on Lesnoy Prospekt.

The Shavrov Sh-2 was developed from the Sh-1 flying boat prototype designed in Korvin-Kerber’s own apartment in his free time, while still team-working at OMOS/Aviatrest. It first flew on 21 June, 1929. The Sh-2 was a slight enlargement of the Sh-1, with some detail improvements as seen above.

SH-1 specs:

The Crew comprised a pilot seated forward, and a mechanic or passenger. The SH-1 hull measured 7.7 m for 3.1 m hight at the tip of her tail. Her Wingspan was 10.7 m and Wing area 24.6 m². Her Weight empty was 535 kg and at normal takeoff reached 790 kg max. She was powered by a “Walter” 85 HP to a top speed of 125 kph and Cruise speed of 104 km/h allowing about 400 km and more than 5h of autonomy while not being able to go further up than 2,470 m. As a prototype no armament of payload was invisioned at that stage.

Design of the SH-2

3d reconstitution of the folded wings (aeroscale.net)

The hull was modelty made of pine wood. The keel and longerons were in ash, and the cover for the fuselage was made of 3 mm (0.11 in) plywood skinning, along 25 frames. Four of theses wete watertight bulkheads in case of a perforation. The bottom was covered with 6 mm plywood (0.23 in), and the entire structure was covered in doped fabric. The cockpit had three seats, and the pilot and passenger sat in tandem in the forward section, both given the same controls, and there was a additional passenger behind or cargo/additional fuel. More storage was provided in the nose and under the seats.

The wings were those of a staggered sesquiplane. The outer wing had a 3 degree dihedral, and could be folded back along the fuselage for easier ship storage. The centre section used aluminium alloy and dead eye were provided forward for hoisting cables. The small cantilevered lower wing also supported the stabilizing floats. There was a cruciform tail, leaf-shaped and reminiscent of De Havilland designs, with horn balanced elevators. The rudder was slightly enlarged compared to the Sh-1 under recommendation, due to the greater speeds and better engine.

The undercarriage was also new, it comprised a retracting gear rotating forward, up ,in an arc or a ral, until the axle was level with the cockpit coaming and pulled into position with cables and springs. It could be swapped for heavy skis for winter operations. A few models had the undercarriage removed entirely and skis fitted permanently. The production went on for an amazing 20 years, stopping in 1955, in between, they were upgraded by being fitted with the more powerful postwar version of the M-11. There were variants with enclosed cabins as well for the aft passenger, enclosed or glassed, or for two stretchers in the ambulance version.

Production (1932-52)

Serial production was ordered at Taganrog Plant No. 31. According other sources, it was in the repair base of the Main Directorate of the Civil Air Fleet (directive pr. UKGVF No. 364 dated June 4, 1931) in Leningrad starting on August 15, 1931. On June 1, 1934, this became the Leningrad Aircraft Repair Workshops (LARM), Civil Air Fleet. The first aircraft left the factory floor on April 1, 1932. The first delivered were configured as air ambulance with a compartment for a stretcher, designed by F. F. Lipgart (16 manufactured). The rest were standard production models, with optional skis also delivered for conversion, mostly on the arctic and baltic.

Exact prduction records are shaky to say the least. It varied among sources, between 300 to 700 and even 1200. Most were apparently made before 1941 as the SH-2 receive lower priority compared to other models and all other Shavrov models were axed (see later). It seems that production was only partial, stopped and restarted at various times: In 1930-1934 for the main bacth, in 1939, in 1942-1945 again, then 1946-1947 (possiblt 700 in all) and in 1951-1952, not 1955 as some sources stated for 1200 total. To be more precise, 270 were produced in 1932-1934 (1932: 30, 1933: 200, 1934: 40. After this, production ceased entirely. Operated aircraft were gradually decommissioned when worn out.

In this regard, the Main Directorate of the Civil Air Fleet decided to rebfurbished and return many decommissioned Sh-2s into service. Restoration and overhaul was carried out by the Leningrad Aircraft Repair Workshops of the Civil Air Fleet (ARM-21). Its simplicity and cheapness was revaluated as well as its cheaper manufacture not using strategic materials, and it was even simpler/cheaper than the Polikarpov U-2. Mass production was resumed in 1939 under the leadership of V. F. Rentel and modernized, further simplifed and given the new M-11D engine, mounted on shock absorbers and with counter struts.

In the summer 1941, 50 of these were being assembled in the workshops. The ARM-21 was evacuated to Irkutsk, in August 1941. On 08/20/1941 it was evacuated to Vologda (where PARM-1 was created) and to Irkutsk to the ARB-403 site. Then, the workshops were relocated to Sverdlovsk, where ARB-404s were organized. In 1943 had the name PARM-79.

During the evacuation, the repair of Sh-2, U-2, R-5 and ANT-9 aircraft continued and assembly was carried out after the repair of G-1 and DB-3 aircraft. Soon there were finished parts for 20 extra Sh-2 sent there for completion in 1942. A New production was organized at the GVF Repair Plant No. 403 and further changes were made to the design mainly due to supply difficultties for some parts now in occupied territory. In total, from 1942 to 1945, 150 new Sh-2s were produced in Irkutsk, 286 repaired/refurbished and modernized.

In 1944 the PARM-79 were returned to Leningrad to Staraya Derevnya, in early 1945 for completion. They received idenfication numbers LARM-21 SUGVF.

There are no exact data on the number of Sh-2s produced for all years. It is known that more than 700 of them were built (according to some estimates – from 800 to 1200). The simplicity and high maintainability of the machine (sometimes they went through 4-5 overhauls) provided this machine with a long life.

After the war, the Irkutsk plant delivered the model in large quantities in 1946-1947 and again in 1951-1952. In 1947, prodyction was relocated to Pulkovo. On September 1949 the facility was renamed LERM, and on 18 August 1952, ARM-21 GVF. On July 5, 1968 the workshops were reorganized into Plant No. 21 GA.

In 1948 they were refusbished with captured German equipment while repair of civilian models and engines upgraded were performed with assembly of joint Po-2/Sh-2 established. The modified version used the M-11L engine (115 hp) and later by the M-11K (125 hp), also modified for easier controls with a compressed air cylinder with trimmers on the rudders height and direction. It also had an enclosed cabin among other things.

Engine

Yak-1 UT-1 advanced trainer also powered by the Shvetsov M-11

This was the Shvetsov M-11 radial, 5 cyclinder air-cooled engine. It was designed under a 1923 competition for a new engine for light, trainer aircraft. It was single-row with five aluminum cylinder heads. Like the American Kinner B-5 5-cylinder radial (obtained), the M-11 had individual camshafts for each cylinder operating pushrods. The initial versions were very weak, only lasting for 50 hours before replacing parts due to low tolerances and high vrbrations. The basic M-11 was capable of 100 hp (73 kW), but ot was refined as the M-11D (125 hp/92 kW), and the last was the M-11FR introduced in 1946 (160 hp at 1,900 rpm) fitted with a variable-pitch propeller and many new accessories as well as a floatless carburetor. The ultimate evolution was the MG-50, projected 18 cylinder, two-row radial designed by M.A. Kossov and delivering 600 kW (800 hp)/630 kW (850 hp) in the 1950s. This engine also powered the Anbo II, Gribovsky G-15, G-20, G-21, G-23, G-27, the Kharkiv KhAI-3, Laz-7M, LWD Junak, MiG-8 Utka, Polikarpov Po-2, PZL S-4 Kania, Shcherbakov Shche-2, Yakovlev UT-1, UT-2, Yak-6, Yak-12 and Yak-18.

Armament

The Shavrov SH-2 was mainly a civilian aicraft, and when pressed into milityary service, painted in green livery for the winter war, still unarmed, many received a rear pintle mount light MG. To operate it, the mechanic/passenger seat was turned backwards, or he was given a simple turning stool. No known installation of small bomb rack under the lower wings is known or shown on any photos, not even the mounted defensive armament. It seems it operated only for liaison/transport only.

Specifications Shavrov SH-2
Crew:	3: Pilot, Gunner, Observer
Dimensions:	Length: 8.2 m (27 ft 11 in) Wingspan: 13 m (43 ft 8 in) Height:
Wing area:	24.7 m2 (265.87 sq ft)
Weight, Max Take off:	937 kg (2066 lb)
Weight, Fully Loaded:	660 kg (1455 lb)
Propulsion:
Top speed:	Top speed: 138 mph (222 km/h, 120 kn)
Cruise speed:	139 km/h 86 mph
Service ceiling:	3,850 m (12650 ft)
Rate of climb: 5,000 ft (1,524 m) in 5 minutes 20 seconds
Endurance:	1,300 km (808 miles), 5h+
Armament:	Optional rear 1x .303 cal (7.7 mm) aft

Service 1930-1959

Interwar and civilian service

The Sh-2 served throughout the Soviet Union, from the Baltic to the Black sea and Pacific as well as from major rivers and a few in the arctic region as initially intended, often painted with bright colors, with yellow and orange patterns. In 1933 the Sh-2 was used for ice reconnaissance during the Chelyuskin steamer expedition, based on board. It was piloted by M.S. Babushkin. After the ship was strabded, the Sh-2 was unloaded on ice and flew to Vankarem.

It was mainly used an a utility transport by the Aeroflot in various liveries depending on the line. It was used for liaison and as a trainer also by the army on small quantities, but also for fishery protection duties, by the coast guard, NKVD, never the Navy. It was also used for frontier patrol also by the NKVD. They supported Arctic operations and 16 were built under the designation Sh-2S as air ambulances carrying one or two stretcher patients. In 1939 Aeroflot built additional Sh-2s from available spares and later the type was reinstated in production. As well as use for the civil roles indicated, the Sh-2 was flown by the V-VS as a general-purpose aircraft. A number of later machines had a glazed crew cabin and other refinements, becoming redesignated Sh-2bis most had improved M-11L engines.

WW2 service

By April 1, 1941, there were 32 serviceable models, 12 not in flying conditions with M-11s yet to be fitted in civilian departments. Another 2 unfliable were in service with the NKVD. The situation changed with the start of the Soviet-Finnish War in 1939 already, as the landscape was well adapted to a small amphibian model for operational communications between units and transport of injured personal. They proved very useful in swampy area, rivers and lakes dotting Finland. It seems it was only “leased” by the Aeroflot to the Army wherever it flew, rarely seen with proper military marking, although many were photographed with red stars. Given the halp-hazard production, they operated in local units until 1945 for their tradtional role, never offensive.

In Finnish hands

In August 1942, two Sh-2S (USSR-X-217 and USSR-X-370) were captured by the Finns near Petrozavodsk, reused by the Finnish Air Force from October 1942 to September 1944. They kept their original olive green livery but had pale blue underbelly and wings, svatiskas, and the classic yellow underwing tip as standardized for the axis in this theater. Their fate is unknown, but photos exists dated up to the end of the continuation war.

Postwar service & legacy

Surviving ones are in the following museums: The Russian State Museum of the Arctic and Antarctic, in St. Petersburg, and the Historic Aviation Restoration Museum in Maryland Highs (Missouri, USA) – see later.
The Youth Aviation Center in Urai, created a flying copy built on 0.75: 1 scale, first demonstrated at the SLA-89 in Riga. She was made by enthusiasts with no prior experience. They sed a small 4-cylinder Praga engine with a 75 hp output, forced its downsizing. It first flew by Sheffer Yu. P., obtained the main prizes at SLA-89. The same team next reconstructed this time a more reastlitic Sh-2, demonstrated at the MAKS-95, MAKS-97 exhibitions and Gelendzhik-96 Gidroaviasalon as well as other air shows. None original survived. The full replica created in USSR by cadets of Egorevsky aviation school of civil aircraft under the direction of teachers, from 1984 to 1986 was purchased in the 1990s, and is now in the Historic Aircraft Restoration Museum in Creve Coeur, Missouri, U.S.A.

Shavrov’s later models

Shavrov SH-3/4

The prototype in construction

Known sketch of the prototype

Unfortunately little survived from both prototypes. The Shavrov Sh-3 was a paper project for a single-engined light amphibious aircraft also used for transport. The programme was abandoned as the prototype was nearing completion in 1936 while 90%, due to an administrative decision. Its specifications were dimensions of 7.80 m (36 ft 7 in) x 14.00 m (46 ft 11 in) (24 m2 (258.33 sq ft)), Empty weight of 720 kg (1,587 lb) and 1,070 kg (2,359 lb) gross. She was to be powered by a Cirrus Hermes , 89 kW (120 hp). It was a very modern all-metal floatplane with two large floats underwing. Both integrated wheels for amphibious operation. As for the SH-4 it’s only mention as another project, also cancelled. Almost nothing is known about it.

Last Shavrov planned replacement: The SH-7

Two photos of the prototype

The Sh-7 was a six-seater amphibious flying boat designed by V. B. Shavrov intended to communicate between polar stations and doing ice reconnaissance from ships as performing other tasks in the northern regions of the USSR. Designed in eatly 1939, she was built and tested in 1940. Tests were conducted by pilot E. O. Fedorenko were successful. It was decided to launch mass production of the Sh-7at the Glavsevmorput repair plant, in the summer of 1941 after the German invasion, there were massive reorganization plans in all sectors and many production orders were cancelled to concentre ron a few models only. Sadly, the promising SH-7 was axed as well. The prototype neverthess served in WW2, transporting mail until completely worn out; Its fate is uncertain.

This martly metal-clad model was a parasol sesquiplane, still with a top center wing-mounted engine. It had a crew of 2 but can carry 4 in its fuselage, or carry a 350 kg payload. 9.4 m long for a 13m wingspan and 23.3 m2 wing aera, it had a wing airfoil profile NACA-23016 (tip 23012). Its Empty weight was 1,230 kg, with a maximum takeoff weight of 1,900 kg and could carry 320 kg of fuel and oil in its internal tanks. Its Power plant was the PD MG-31F rated 330 hp and driving a two-bladed wooden propeller. Wing loadingw as 81 kg/m2. Top speed was 218 km/h with a normal ferry range of 920 km, ceiling of 3000 m, and takeoff run on a flat surface of 215 m and run length of 107 m. It was armed with a defensive TT-1 mount for a ShKAS machine gun (300 rounds) aft.

Books

Петров Г. Ф. Гидросамолёты и экранопланы России. 1910 — 1999. — М.: Русское авиационное акционерное общество (РУСАВИА), 2000. — С. 222. — 248 с.
Шавров, В. Б. История конструкций самолётов в СССР до 1938 г. — 3-е. — М.: Машиностроение, 1985. — 752 с.
С. Малик. Самолет-амфибия Ш-2 // Моделист-конструктор : журнал. — 1976. — № 6. — С. 23-28.
А. Б. Григорьев. Альбатросы: Из истории гидроавиации. — М.: Машиностроение, 1989. — 270 с.
Игорь Костенко. Историческая серия «ТМ»: Крылатая амфибия // Техника — молодёжи : журнал. — 1978. — № 6. — С. 46-47. Архивировано 4 марта 2016 года.
Маслов М. Амфибия Ш-2 и другие самолёты Вадима Шаврова. — М.: “Цейхгауз”, 2008. — 48 с. — ISBN 978-5-9771-0063-2.

Links

some foorage of the Sh2
airwar.ru
armedconflicts.com
eaaforums.org
secretprojects.co.uk
ram-home.com
airpages.ru
wikipedia.org/wiki/Shavrov_Sh-2
Wiki Ru Sh3
Sh-2 on aviastar.org
about the sha-3 on aviastar
aviarmor.net
scalemodels.ru
amyat.narod.ru
museum.ru
e-reading-lib.com

The model corner

Its Drawings for modeling were published in the russian magazine “Model Designer”. Kits were produced by the Ukrainian Amodel (1:72, plastic injetion) and the Oryol publishing house (1:33, paper model).
General query on scalemates
SH-2 on scalemates.com/
super-hobby.co.uk
On britmodeller.com
modelingmadness.com

Refs

basilzolotov.com
britmodeller.com
www.airwar.ru
www.airliners.net

Gallery

Author’s illustrations: Types and liveries

Shavrov-SH-2

Flying Ambulance

Equipped with skis for arctic and winter operations

Propaganda flights model of the NKVD

Green model with skis

Aerofolot model in Military use 1941

Finnish model 1942

Additional photos

shavrov-sh-2-plan

Shavrov_Sh-2_display-US

Fuselage construction Sh1 1928

Wing-construction Sh1 1928

Sh2-scan

Central-construction-construction-Sh1-1928

Fuselage-underconstr-Sh-1_1928

Shavrov_Sh-2_СССР_К8_Ambulance

Shavrov_Sh-2_Monino

sh2-design-diff

dsignSH2-3v

sh2bgHD

designSh2-pubrus

Sh-2cockpitatYegorievskTechSchool

shavrov-sh-2-desgn-cockp

sh2-orig-bp

diffSh1Sh2-ft

Sh2-plans

sh2-det-plans

Shavrov_Sh-2_cockpit

sh2specs