Yermolayev Yer-2 with Klimov M-105 engines 1941

Designed by V. G. Yermolayev, previously a member of the design team concerned with the STAL series of aircraft, the DB-240 long-range bomber prototype was flown for the first time in June 1940. A second prototype followed in September, by which time preparations for mass production at Voronezh were in hand, but the German invasion led to evacuation of the factory in July 1941, by which time 128 examples of the DB-240 had been delivered under the designation Yermolayev Yer-2. An all-metal midwing monoplane of inverted gull-wing configuration and with a twin fin-and rudder tail unit, the Yer-2 had tailwheel landing gear, the main units retracting into the nacelles of its two M-105 engines; accommodation was provided for a crew of four.

By the autumn of 1941 the Yer-2 was in action with two air regiments, making attacks as far distant as Berlin and Konigsberg, but the need for increased range led to experiments with AM-35 engines (April 1942) and a modified wing. Following tests with Charomsky diesels, a new version with ACh-30B engines was approved for production in December 1943 at the Yer-2 factory, which was then established in Siberia. The Soviets experimented extensively with aircraft Diesel engines. Versions of the Pe-8 and Yer-2 were powered by them, but their power-to-weight ratio was too low for modern aircraft, despite their excellent fuel economy. This was the problem all aero-diesels had. The best that was achieved was 2 pounds per horsepower, whereas 1 pound per horsepower was common with gasoline engines.

Some 300 examples of the Yer-2/ ACH-30B were built, forming the backbone of the Soviet long-range bombing force; they also incorporated some improvements, including a revised cockpit, a larger-calibre machine-gun in the ventral position and an enlarged bomb bay accommodating three 1000-kg (2,204-lb) bombs. Maximum speed of this version was 446 km/h (277 mph) and its range 5000 km (3,107 miles), but despite this capability most Yer-2 operations were of necessity carried out at short range on targets behind the front line.

Variants

* Yer-2 production

* Yer-2-ACh-30B

* Yer-2-ACh-30BF

* Yer-2ON ("Osobogo Naznacheniya", "special purpose")

* Yer-2 carrier

Specification

Yer-2 (first series)

Type: long-range bomber

Powerplant: two 783-kW (1,050-hp) Klimov M-105 Vee piston engines

Performance: maximum speed 491km/h (305 mph); service ceiling 7000 m (22,965 ft); range 4000 km (2,485 miles)

Weights: empty equipped 6500 kg (14,330 lb); maximum take-off 11920kg (26,279 lb)

Dimensions: span 23.00 m (75 ft 5 ½ in); length 16.34 m (53 ft 7 1/3 in); wing area 72.00 m2 (775.03 sq ft)

Armament: one 12.7-mm (0.5-in) UBT and two 7.7-mm (0.303-in) ShKAS machine-guns, plus a bombload of up to 1000kg (2,204 lb)

Pe-8 Heavy Bomber

Pe-8 VIP which carried USSR Foreign Minister Vyacheslav M. Molotov from Moscow to Washington on RAF Leuchars airfield , near Dundee, Scotland, in May 1942.

The Petlyakov Pe-8 was the Soviet Union’s only modern four-engine bomber of World War II. Design of the aircraft was initiated in July 1934 by Vladimir. M. Petlyakov’s team headed by A.N. Tupolev. It was created to develop an aircraft to replace the TB-3 heavy bomber and meet a list of new requirements. Among these were the ability to reach 8000 meters (12,640 feet) in altitude, carry a two ton bomb load, and attain a speed of 273mph (440kph). A cantilever mid-wing monoplane of all-metal construction, except for fabric-covered control surfaces, the ANT-42 as it was then known had retractable tailwheel landing gear with only the main units retracting.

The first aircraft was made in the autumn of 1936. The ANT-42 was the nation’s first all-metal heavy bomber with smooth covering and retractable undercarriage. To increase the altitude tolerance of the AM-34FRN engines installed on the bomber, provision was made for a central supercharger whose functions were performed by the fifth engine.

The manufacture of five pre-produc­tion aircraft was authorised in April 1937, but there was a subsequent attempt to end the programme. The project was disrupted in October of 1937 when both Tupolev and Petlyakov were arrested. Stalin's purges of the Red Air Force officer corps in 1938 also delayed the program. Even with these delays the first prototype flew on 27 December 1937 and performed very well in the early trials.

When first flown on 27 December 1936 the ATsN supercharger installation was not available and the ANT-42 was powered by four 820-kW (1,100-hp) Mikulin M-100 Vee engines. Although the aircraft was damaged subsequently in a heavy landing, official testing was completed during 1937, following which the ATsN supercharger, driven by a single M-100 engine, became available. The second prototype ANT-42 was flown on 26 July 1938, this having many improvements including an ATsN-2 supercharger driven by an M-100A engine. Petlyakov's team soon ran into problems with the original engines which were not sufficiently powerful at altitudes over 5000 meters (11,025 feet). This problem was solved with the selection of four M-105 engines supercharged by a M-100 engine in the rear fuselage. It was also tested with skies for landings on ice and snow, but these were replaced with large tires which functioned better.

The aircraft demonstrated high flight performance. With a normal flight weight of about 24tonnes, the aeroaircraft could gain a speed of 403 km/h at an altitude of 8,000 m and climb to a height of 10,800 m. At high altitudes the ANT-42 was considered superior to all known heavy bombers and competitive with the best fighters.

In series production, the dimensions of the aircraft were not altered (span 39.01 m, wing area 188.68 m2, length 23.59 m) but different engines were used: AM-35A, ASh-82 and world’s first aviation diesel engine M-40 and its modified version ACh-30B. As a result, the aircraft flying range increased significantly with a slight reduction in other flight characteristics. The aeroaircraft could carry up to 4,000 kg of bombs and was equipped with powerful defensive armament.

In the spring of 1938 plant No. 124 in Kazan started production of the TB-7 and these five pre-­series aircraft differed from the ANT-42 by having the ATsN central supercharger installation deleted and the main engines replaced by supercharged AM-35s. At the same time several air­frame improvements were introduced and deliveries of these pre-production aircraft began in May 1940.

The completion of the first production batch of Pe-8s and the creation of a special unit for them--the 432nd BAP (ON) (Bombardirovachnyi Aviapolk Osobovo Naznacheniya, or special purpose bomber regiment) under Major Viktorin I. Lebedev--coincided with the 1941 German invasion. The bombers were promptly committed piecemeal in a series of short-range night attacks on railheads and staging areas that did little or nothing to slow the German advance. The surviving 18 operational aircraft were used to activate a regiment designated 412. The regiment started its combat activity by mounting an air raid to Berlin on the night of August 10 to 11.

Performance with the AM-35 powerplant was disap­pointing, leading to the evaluation of several different engines, but in October 1940 the 1044-kW (1,400-hp) ACh-40 diesel was selected as standard power­plant. This proved unreliable, bringing continued use of the 1007-kW (1,350-hp) AM-35A until those in service were re-­engined with the 1119-kW (1,500-hp) ACh-30B diesel.

Pe-8 heavy bombers formed a part of the Soviet long range aviation forces. It was used alongside the IL-4 as a strategic bomber, which made up the bulk of the bomber fleet. The bomber was a versatile weapons platform with fairly heavy defensive armament. It could also carry a wide variety of high explosive bombs (as can be seen in the table to the right). It was also capable of carrying mines, target markers, or VAP-500 and VAP-1000 chemical weapon dispensers.

One aircraft with AM-35A engines made a re­markable staged flight from Moscow to Washington carrying Molotov (then Soviet Foreign minister) flight to Washington from Moscow (17,700km) with landings in Scotland, Iceland and Canada and then back during the period 19 May to 13 June 1942. Surviving air­craft were used extensively during 1942-43 for close-support bombing and, from February 1943, were used to deploy the FAB-5000NG 5000-kg (11,023-Ib) bomb for point attacks on special targets.

In 1942 the aircraft was re-designated the Pe-8 (Note 1), in honor of Petlyakov who had been killed earlier that year. Also during this time there were also attempts to improve the Pe-8's engines, but these were not entirely successful. By the mid-1944 about 30 had been re­-engined with the ASh-82FN.

Production ended in mid/late 1944 a total of 91(Note 2) had been built. The last four aircraft were converted into VIP transports. These had the bomb bay removed and additional passenger seats added. Cargo capacity was also increased and all military equipment was deleted. The range of the new aircraft was increased to 7000 kilometers (4,350 miles).

Post-war about 30 Pe-8s survived. In the years following the war most of the Pe-8 bombers were converted to the transport configuration. Many were operated by Aeroflot or used for polar scientific research expeditions. In 1952 two of them played a key role in establishing an Arctic station before returning the expedition to Moscow in a non-stop flight of 5000 km (3,107 miles). The remaining Pe-8's were used to test aircraft engines, high speed research aircraft, and cruise missiles based on wartime German plans. Some of the research aircraft were used as late as 1957.

Pe-8 Notes:

1. TB-7 was re-designated Pe-8 in 1942. All the Russian sources give us that year. The most trusted is "History of Aircraft Construction in the USSR in 1938-1950" written by V.B. Shavrov and published in 1994 (3rd print). Quote: "After the death of V.M. Petlyakov in 1942 the name of the aircraft was approved as Pe-8". Petlyakov died in the air accident on January 12th, 1942 (the aircraft of Senior Lieutenant F. Ovechkin caught fire in the air and crashed near village Mameshevo). So, the TB-7 was re-designated Pe-8 early in 1942.

2. 93 TB-7 (Pe-8) were produced. 2 prototypes and 91 serial aircraft. The fates of these aircraft are highlighted in a previous post.

Petlyakov Pe-8 Specification
Designer - Vladamir Petlyakov
Role: Heavy Strategic Bomber
Year Adopted: 1940
Operational Status: USSR (Produced from 1940 to 1944)
Armament: 2 x 20mm cannon4 x 7.62mm ShKAS Machine Guns8818 lbs (4000 kg) of bombs
Engines: 4 x Mikulin AM-35A, 12-cylinder, liquid-cooled, 1,350 hp engines
Crew: 10
Wingspan: 131 feet(39.94 meters)
Length: 73 feet, 9 inches(22.49 meters)
Height: 20 feet(6.1 meters)
Maximum Speed: 272 miles per hour at 24,930 feet altitude(438 kilometers per hour at 7,600 meters altitude)
Take-Off Weight: 73,469 lbs (loaded)33,325 kg (loaded)
Ceiling: 22,965 feet(7,065 meters)
Range: 3,383 miles(5,445 km)

LaGG-3

The appearance of these highly polished wooden fighters soon earned them the nickname of "Grand Pianos".

Born at Smolensk in 1900, Semyon A. Lavochkin could look forward to few opportunities for social or professional advancement in Csarist Russia because he was Jewish. Lavochkin was finishing school at the Kursk Gymnasium when the Bolshevik Revolution broke out in 1917. After three years of combat in the Red Army, he was accepted at the Moscow Aviation Institute in late 1920, and graduated with high honors.

Forming a design team with Vladimir P. Gorbunov and Mikhail I. Gudkov in May 1938, Lavochkin designed his first original airplane in response to a Soviet requirement for a new-generation fighter to replace the Polikarpov I-15 biplane and I-16 monoplane. The I-22 or LaGG-1 prototype was powered by a Klimov M-105P in-line, water-cooled engine. It flew on March 30, 1939, and entered service in 1940. With an improved M-105PF engine and some modifications, it entered full production as the I-301 or LaGG-3.

To circumvent shortages of steel tube and light alloy in the aircraft industry, the LaGG-3 was mainly constructed of delta drevesina (delta timber), a plastic-impregnated birch plywood, developed by L.I. Ryzhkov, that was fire-resistant and exceptionally strong. The appearance of these highly polished wooden fighters soon earned them the nickname of "Grand Pianos" from the pilots, but later nicknames for the LaGG-3 were to be less affectionate. Underpowered and overweight, the LaGG-3 also revealed a tendency to go into a sudden, vicious spin from a steep banking turn. Although a few experienced Soviet pilots had a measure of success in the LaGG-3, pilots in most outfits were inadequately prepared for its unforgiving characteristics. Many interpreted LaGG as an acronym for "Lakirovanny Garantirovanny Grob" (varnished, guaranteed coffin), and their lack of confidence in their aircraft stood them in poor stead against their highly skilled Luftwaffe opponents.

In October 1941, Gudkov began studies into the possibilities of replacing the water-cooled M-105 with the air-cooled Shvetsov M-82 14-cylinder engine. Lighter and generating 1,540 hp against the M-105's 1,100 hp, the M-82 had an almost miraculous effect on the performance, maneuverability and durability of the basic LaGG-3 airframe. Rushed into production in the summer of 1942, the LaG-5 radial-engine fighter was an interim improvisation that soon gave way to the La-5, a more refined version with the improved M-82F engine, a strengthened airframe, and the rear fuselage cut away to improve visibility. The single 20mm cannon and twin 7.62mm machine guns of the LaGG-3 were replaced by two 20mm cannon in the La-5.

The La-5FN, powered by a 1,650-hp M-82FN engine cooled by a distinctive air intake above the cowling, was a significant improvement. It had metal fuselage longerons, wings of greater span and narrower shord, and introduced automatic boundary layer control--suction-powered leading-edge slats.

Designed for combat below 15,000 feet, the La-5s generally outperformed their Luftwaffe opponents at the low altitudes dictated by the principally tactical war fought over Russia. At their best at higher altitudes, the Messerschmitt Bf-109G and Focke-Wulf Fw-190A fighters were also less durable than the Lavochkins when operating in the harsh field conditions of the Eastern Front.

The change from in-line to radial engines had as dramatic an effect on Semyon Lavochkin's career as it had on the aerodynamics of his fighter. Discredited for the LaGG-3's poor service record, he was awarded the Order of Lenin and the Gold Star of a Hero of Soviet Labor for the success of the La-5 series.

The ultimate wooden Lavochkin, the La-7, was another interim design, put into production late in 1943 pending development of the all-metal La-9. Its M-82 FNV engine generated 1,850 hp and, with the air intake moved under the fuselage, the cowling was one of the most streamlined ever to enclose a radial engine. Armament was increased to three 20mm ShVak or 23mm NS cannon, which could be supplemented by six RS-82 rockets or 331 pounds of bombs on underwing racks. The La-7 had a wingspan of 32 feet, 5 3/4 inches, and was 27 feet, 4 inches long. Maximum speed was 423 mph at 20,997 feet. Takeoff weight was 7,496 pounds. Reaching the front late in 1944, the La-7 was arguably the best Soviet low- and medium-altitude fighter of World War II.

Semyon Lavochkin continued to be active in the aviation field until his death in 1965, but never matched the success of his World War II designs. Those subsequently were eclipsed by the team of Artem I. Mikoyan and Mikhail I. Gurevich, whose MiG-1 and MiG-3 fighters had done poorly during the war years, but whose designs came brilliantly into their own in the jet age.

Summary: First indigenous Soviet medium tank, but clearly influenced by both the Vickers A6 and German Grosstraktor designs. Intended for an attack role, it had a central main-gun turret and two machine-gun turrets in front to either side. Its suspension was copied from the Vickers tank. It served in the 1939-1940 Winter War with Finland and in the opening weeks of the German invasion of the Soviet Union in June 1941 but performed poorly in combat. Subsequent variants included the T-28C with increased hull front and turret armor.

Evaluation

Although the T-28 was rightly considered ineffective by 1941, it is worth remembering that when the Red Army was fielding the first T-28s in 1933, the French Army was still largely equipped with the FT-17, and the Reichswehr had no tanks at all. No army had a series-production medium tank comparable to the T-28 for several years.

The T-28 had a number of advanced features for the time, including radio (in all tanks) and anti-aircraft machine-gun mounts. Just before the Second World War, many received armor upgrades, bringing its performance on par with the early Panzer IV, although its suspension and layout were outdated. [5]

The T-28 had significant flaws. The plunger-spring type suspension was poor, but many of the better suspension designs used in World War II tanks had not yet been developed. The engine and transmission were troublesome. Worst of all, the design was not flexible. Although the T-28 and early PzKpfw IV were comparable in armour and firepower, the good basic design of the PzKpfw-IV allowed it to be significantly upgraded, while the T-28 was a poor basis for improvement.

Unfortunately for the Red Army, by the time the T-28 saw combat in 1939, events had overtaken it. The 1930s saw the development of the first reliable high-speed suspensions, the first purpose-designed antitank guns, and a gradual increase in the firepower of tanks. The Spanish Civil War showed that infantry units with small, towed anti-tank guns could defeat most contemporary tanks, and made the under-armoured tanks from the early 1930s particularly vulnerable.

Despite heavy losses, in the Winter War the Red Army's 20th Tank Brigade, equipped with T-28s, fulfilled its mission to break the defensive Mannerheim Line. As an infantry-support tank, designed to support infantry in breakthrough operations, the T-28 in general was successful for an early 1930s design.

Variants

• T-28 Model 1934 or T-28A - main production model with the same machinegun turrets, and similar main turret as the T-35 heavy tank and Model 27/32 76.2mm gun.
• T-28 Model 1938 or T-28B - version with improved L-10 76.2 mm gun (from 16.5 calibres to 26 calibres), improved gun stabilization system and improved Model M-17L engine.
• T-28E or T-28C - 1940 addition of appliquĂŠ armour in response to poor performance in Finland. Total front armour was increased to 80 mm, weight to 32 t, and road speed dropped to 23 km/h
• T-28 Model 1940 - the final batch of about twelve tanks had the same conical turret as late-production T-35 tanks.
• OT-28 - flamethrower version.

Experimental models

Several self-propelled guns, the IT-28 bridging tank, and an engineering vehicle with mine rollers were tested on the T-28 tank chassis, but none was accepted for production. The T-29 was a prototype medium tank, a modernized T-28 with Christie suspension - a later version of this vehicle was considered for the competition of prototypes which led to the T-34, but by then it was outdated (not to be confused with a Grotte tank project also called T-29). The T-28 also served as a testbed for the KV tank suspension.

Production dates: 1933-1940

Number produced: 503

Manufacturer: Leningrad Korov Plant

Crew: 6

Armament: 1 x 76.2mm (3-inch) low-velocity main gun M1927; 3 x 7.62mm DT machine guns (some T-28s mounted a low-velocity 45mm gun in the right auxiliary turret in place of the machine gun)

Weight: 62,720 lbs.

Length: 24'5"

Width: 9'5"

Height: 9'3"

Armor: maximum 30mm; minimum 10mm (maximum 80mm on T-28C)

Power plant: M-17 V-12 500-hp gasoline engine

Maximum speed: 23 mph

Range: 137 miles

Vertical obstacle: 3'5"

Trench crossing: 9'6"

Special models: commander's tank T-28 (V) with radio antenna frame around turret; small number of flamethrower tanks

The first indigenous Soviet medium tank design, the T-28, incorporated multiple turrets and was intended for an independent breakthrough role. Inspired by the Vickers A6 (its suspension was a clear copy) and German Grosstraktor designs, it grew out of the 1932 Red Army mechanization plan and was first produced by the Leningrad Kirov Plant. Intended for an attack role, the T-28 had a central main gun turret and two machine-gun turrets in front and to either side. The T-28 weighed 28,560 pounds, had a six-man crew, and was powered by a 500-hp engine and had a road speed of 23 mph. It had only 30mm maximum armor protection. The prototype mounted a 45mm gun, but production vehicles had a 76.2mm low-velocity main gun and two machine guns. Combat experience with the T-28 led to changes. Armor was increased on the C version to 80mm for the hull front and turret. Some T-28s substituted a low-velocity 45mm gun in the right front turret for the machine gun normally carried there. The T-28 had a poor combat record, however.

Production history

The T-28 was in many ways similar to the British Vickers A1E1 Independent tank. This tank greatly influenced tank design in the period between the wars, although only one prototype was manufactured in 1926. The Kirov Factory in Leningrad began manufacturing a tank, which was based on the British Independent in 1932. The T-28 tank was officially approved on August 11, 1933. The T-28 had one large turret with a 76.2mm gun and two smaller turrets with 7.62mm machine guns. A total of 503 T-28 tanks were manufactured over a period of 8 years from 1933 to 1941.

The type would not have that much success in combat, but it played an important role as a development project for the Soviet designers. A series of new ideas and solutions were tried out on the T-28 and were later incorporated in future models.

Combat history

The T-28 was deployed during the Invasion of Poland and the Winter War against Finland. During the initial stages of the Winter War, the tank was used in direct fire missions against Finnish pillboxes. In the course of these operations it was found that the armour was inadequate and programs were initiated to upgrade it. Frontal plates were upgraded from 50 mm to 80 mm and side and rear plates to 40 mm thickness. With this up-armoured version the Red Army broke through the main Finnish defensive fortification, the vaunted Mannerheim Line.

According to Russian historian M. Kolomietz's new book T-28. Three-headed Stalin's Monster, over 200 T-28s were knocked out during the Winter War, but only 20 of them were in irrecoverable losses (including 2 captured by the Finnish Army). Due to proximity of the Kirov Plant, all other knocked-out tanks were repaired, some of them over five times.

The Finns knew the T-28 as the Postivaunu ("mail wagon" or stagecoach), a name which alluded to Finnish troops' discovery of Red Army field mail sacks inside the first destroyed T-28. Another explanation is that the high profile of the tank resembled the old west stagecoaches of the United States. Finns captured two T-28s during the Winter War and five in Continuation War, totalling 7 vehicles.

The Soviets had 411 T-28 tanks when the Germans invaded in June 1941. Most T-28s were lost during the first two months of the invasion, many of them abandoned after mechanical breakdown. Some T-28s took part in the 1941 winter defence of Leningrad and Moscow, but after late 1941, they were rare in Red Army service; a few were operated by enemy forces.

Today three T-28s remain, two in Finland and one in Moscow. One restored T-28 is on display in Finnish field camouflage in the Parola Tank Museum, Finland.