Monday, November 12, 2018

British Mark I Tank

As Little Willie was making its appearance, Foster was completing work on a battlefield version. Because the chief requirements for the vehicle were that it be able to cross open ground as well as wide trenches, Tritton and Wilson came up with a lozenge-shaped design with a long, upward-sloping, tall hull and all-around tracks on either side that carried over its top. These maximized the vehicle's trench crossing ability. Because a turret would have made the machine too high, its designers mounted the guns in sponsons, one on either side of the hull. As it turned out, this was not a satisfactory arrangement. The resulting machine was first known as "Centipede," then "Big Willie," and finally "Mother."

Mother first moved under its own power on 12 January 1916. Thirty-two feet long and weighing some 69,400 pounds, it debuted on 29 January 1916 in Hatfield Park, within a mile of Lincoln Cathedral and under extremely tight security. A second demonstration on 2 February took place in front of British military and political leaders, including cabinet members. In Swinton's words,
it was a striking scene when the signal was given and a species of gigantic cubist steel slug slid out of its lair and proceeded to rear its grey hulk over the bright-yellow clay of the enemy parapet, before the assemblage of Cabinet Ministers and highly placed sailors and soldiers collected under the trees.

Although Mother met the expectations placed on it, even crossing a 9-foot trench with ease, Kitchener was unimpressed. He held to his already stated belief that the new weapon was little more than "a pretty mechanical toy." But Kitchener was in the minority. Most of those in attendance were quite persuaded as to the new weapon's potential. The enthusiasts included Chief of the Imperial General Staff Sir William Robertson, Prime Minister Balfour, and Lloyd George. Balfour was even given a ride. Churchill was certainly correct when he wrote in his memoirs that Mother was "the parent and in principle the prototype of all the heavy tanks that fought in the Great War."

Another trial was held on 8 February before King George V. Three days later the BEF in France requested the new weapon be sent there, and shortly thereafter the government ordered 100 units (later increased to 150), with production to be overseen by a new committee.

Unfortunately, the perceived need to rush the new weapon into production meant that design flaws remained largely uncorrected. For one thing Mother was woefully underpowered. The 28-ton vehicle was propelled by a 105-hp Daimler engine, the only one available. This translated into only 3.7 horsepower per 1 ton of weight. Half of Mother's eight-man crew was engaged simply in driving it: one as commander, another to change the main gear, and two "gearsmen," or "brakemen," who controlled the tracks; the remaining four men manned two 6-pounders (57mm/2.25-inch) and two machine guns. The new machine was also insufficiently armored. Its 10mm protection could not keep out German armor-piercing bullets at close range, and a direct hit by a high-explosive artillery round would most likely be fatal.

The production model, known as the Mark I, was almost identical to Mother. It weighed some 62,700 pounds and had a top speed of only 3.7 mph-over rough ground only half that-and it had a range of some 23 miles. Its principal parts were a simple, steel box-type armored hull, two continuous caterpillar tracks, a 105-hp Daimler gasoline engine, and armament of cannon and/or machine guns.

A two-wheeled trailing unit assisted with steering, but this was soon discarded as ineffective over rough ground and vulnerable to enemy fire. The clutch-and-brake method was then employed on the tracks but required four crewmen. And though it could span a 10-foot trench, the Mark I was only lightly armored in the mistaken belief that this would be sufficient to protect against rifle and machinegun fire. Armor varied in thickness from 6mm to 12mm.

Turning the tanks was a time-consuming, difficult process. One British participant in the Battle of Cambrai recalled that rounds

were striking the sides of the tank. Each of our six pounders required a gun layer and a gun loader, and while these four men blazed away, the rest of the perspiring crew kept the tank zig-zagging to upset the enemy's aim. . . . It required four of the crew to work the levers, and they took their orders by signals. First of all the tank had to stop. A knock on the right side would attract the attention of the right gearsmen. The driver would hold out a clenched fist, which was the signal to put the track into neutral. The gearsmen would repeat the signal to show it was done. The officer, who controlled two brake levers, would pull on the right one, which held the right track. The driver would accelerate and the tank would slew round slowly on the stationary right track while the left track went into motion. As soon as the tank had turned sufficiently, the procedure was reversed.
In between pulls on his brakes the rank commander fired the machine gun.  

The Mark I came in two types. Half of them mounted two 6- pounder/.40-caliber naval guns in sponsons, or half-turrets, on the sides that provided a considerable arc of fire, with four machine guns; these were known as the "male" version. The "female" version mounted six machine guns and was intended to operate primarily against opposing infantry.

The name "tank," by which these armored fighting vehicles became universally known, was intended to disguise the contents of the large crates containing the vehicles when they were shipped to France. The curious would draw the conclusion that the crates held water tanks. The French made no such effort at name deception; they called their new weapon the char (chariot).

The Mark I was the mainstay of tank fighting in 1916 and early 1917, but it had notable defects. The stabilizer tail proved worthless; its fuel tanks were in a vulnerable position; the exhaust outlet on the top emitted telltale sparks and flame; and there was no way for a "ditched" tank to retrieve itself. Some of these deficiencies were addressed in the Marks II and III. These tanks appeared alongside the Mark I in early 1917.

Summary: The first production model tank, essentially a copy of "Mother," designed by William Tritton of Foster & Co. of Lincoln. The Mark I first saw action in the Battle of the Somme on 15 September 1916.
Production dates: January 1916-
Number produced: initial order was 150
Manufacturer: Foster & Co., Lincoln
Crew: 8
Armament: Male version, 2 x 57mm (6- pounders) mounted in sponsons on sides and four machine guns; female, no main gun but six machine guns
Weight: 28,450 kg (62,721 lbs.)
Length (excluding gun): 32'6" (including tail)
Width: 13'9"
Height: 8'2"
Armor: maximum 12mm; minimum 6mm
Power plant: Foster-Daimler 105-hp gasoline engine
Maximum speed: 3.7 mph
Range: 23 miles
Vertical obstacle: 4'6"
Trench crossing: 11'6"
Special characteristics (pos/neg): steering assisted by means of a two-wheeled trailing unit, which was soon discarded as ineffective over rough ground and being vulnerable to enemy fire

Tupolev Tu-2 and Variants

The Tu-2 was a Soviet medium bomber that compiled an impressive record in World War II. Its success is especially remarkable considering that it was designed in a prison.

In 1937 the Russian aircraft engineer Andrei Tupolev was accused of passing secrets to the Germans and was incarcerated in a Soviet gulag. He and his entire staff languished for two years until they obtained promises of early release in exchange for designing a new bomber for the Red Air Force.

Work commenced from behind prison walls, and in January 1941 the prototype first flew. It was designated “Aircraft 102,” for Tupolev’s status as a nonperson precluded using his initials! The new machine was a strikingly clean, twin-engine design with smooth engine cowlings, a pointed profile, and twin rudders. During flight tests it demonstrated even better performance than the Petlyakov Pe 2s then in service. It was slow going at first, but the German invasion of the Soviet Union in June 1941 dramatically accelerated the pace of production.

The Tu-2 proved itself a fine machine, especially in terms of speed, payload, and handling. The big, rugged craft was especially popular with crews for its amazing ability to absorb damage and remain aloft. Initial deliveries did not commence until late 1944, and then in only limited numbers. This was because the Tu-2 was more complicated to build than the Pe-2 and took longer to assemble. Another reason is that the Pe-2 was already serving capably— and in large numbers—so Tupolev’s new machine did not receive priority production. Nonetheless, by 1945 Tu-2s were a common sight in the skies over Eastern Europe, and they had a devastating effect upon German troops and armor.

Consequently, Tupolev was rehabilitated and received the Stalin Prize for his achievement. Tu-2s remained in production until 1948, following a production run of 2,557 machines. Forces under the United Nations encountered them during the Korean War in 1950, and Tu-2s also flew with communist satellite air forces until 1961.


Created during A N Tupolev's period in detention under a ludicrously false 'show trial' charge, the Tu-2 (previously 'Aircraft 103', but really the 58th 'ANT' design), was an outstanding multirole tactical bomber. Its ridiculous gestation, with its creator working on a drawing board in a locked cell, meant that it did not enter service until May 1942, but despite this some 3,300 were delivered from Factories 156, 166 and 125. As soon as spare examples became available they were snapped up for use as test-beds. The very first series aircraft, No 100716, was used to test the ASh-83 engine, rated at l,900hp, driving four-blade AV-5V propellers (replacing the standard 1,850hp ASh-82FN driving the three-blade AV-5V-167 or four-blade square-tip AV-9VF-21K). Maximum speed of this testbed was 635km/h (395mph) at 7,100m (23,294ft).

Numerous test versions appeared in 1944, including the first two of three Shturmovik (armoured ground attack) versions with special armament, all proposed by Tupolev's armament brigade leader A D Nadashkevich. The first, actually given the designation Tu-2Sh, had its capacious weapon bay occupied by a specially designed aluminium box housing 88 modified PPSh-41 infantry machine carbines (sub-machine guns). These fired standard 7.62mm pistol ammunition, and all fired together pointing obliquely down at a 30° angle. The obvious shortcoming was that, even though the drum magazines held 71 rounds, they were quickly emptied.

The second 1944 Sh version had a massive 75mm gun under the fuselage, reloaded by the navigator. Two more ground-attack versions appeared in 1946. The first had the devastating forward-facing armament of two 20mm ShVAK, two NS-37 and two NS-45. The 37mm gun was 267mm (101/2in) long and weighed 150kg (331 lb). The 45mm version had a shorter barrel but still fired its 1.065kg (2.35 lb) projectiles at 850m (2,790ft) per second, and weighed 152kg (335 lb).

The last of these variants was the two-seat RShR, or Tu-2RShR. This was a dedicated anti-armour aircraft, carrying a high-velocity 57mm RShR automatic cannon with the barrel projecting ahead of the metal-skinned nose and fitted with a prominent recoil brake.

The most startling modification was the Tu-2 Paravan (paravane). Two of these were built, to test a crude way of surviving impact with barrage-balloon cables. A special cable woven from high-tensile steel was run from one wingtip to the other via the end of a monocoque cone projecting over 6m (20ft) ahead of the nose. The nose and wingtips were reinforced. First flown in September 1944, this lash-up still reached 537km/h (334mph) despite the strange installation and a 150kg (331 lb) balancing weight in the tail. These trials were not considered to have been successful.

Yet another 1944 modification was the Tu-2K (Katapult), fitted with test ejection seats. The first Tu-2K fitted the test seat in the navigator's cockpit just behind the pilot. A second ejection-seat tester had the experimental seat mounted in an open cockpit at what had been the radio operator's station in the rear fuselage.

In early 1945 the Type 104 radar-interception system began flight testing (the first to be airborne in the Soviet Union). The system had been designed from 1943, by a team led by A L Mints, and the Type 104 test aircraft had begun flight testing on 18th July 1944 but with the vital radar simulated by ballast. The pilot had a modified sight, which was later linked to the radar, and fired two VYa-23 cannon installed under the forward fuselage. The rear fuselage was faired over and contained nothing but a balancing mass.

The designation Tupolev Tu-2G was applied to several Gruzovoi (cargo) conversions. It appears that all of these were experimental, carrying special loads either in the remarkably large bomb bay or slung externally, and in many cases the load was dropped by parachute. No fewer than 49 GAZ- 67b armoured reconnaissance cars were dropped, the Tu-2G in this case being limited to a height of 6km (19,685ft) and a speed of 378km/h (235mph).

The German Fi 103 ('V. 1') flying bomb was the basis for a large Soviet programme of air-launched cruise missiles in the immediate post-war era. One of the later variants was the 16Kh Priboi (surf, breaking waves). The fact this was fitted with twin engines meant that it could be carried under the Tu-2. The first modified Tu-2 launch aircraft began testing at LII on 28th January 1948, and live missile launchings took place on the Akhtuba range between 22nd July and 25th December 1948, testing the D-312 and D-14-4 engines and various electric or pneumatic flight-control systems. The Tu-2 launch aircraft continued in the process of refining guidance and improving reliability until at least 4th November 1950, by which time the Tu-4 was being modified as carrier aircraft with one missile under each outer nacelle. The WS rejected the 16Kh on grounds of poor accuracy, and eventually the argument reached Stalin who shortly before his death terminated this missile.

Experimental Tu-2 aircraft were also used to develop air-refuelling.

Not least, in the immediate post-war era the Tu-2 was the most important aircraft converted to air-test turbojet engines. Occasionally the designation Tu-2LL (flying laboratory) was used, but one of the most important was (possibly unofficially) designated Tu-2N, because it was allocated to test the imported Rolls-Royce Nene. This required the test engine to be mounted in a nacelle of large diameter (basic engine diameter 1.26m, 4ft 11/2in). Later more than one Tu-2 was used to test Soviet RD-45 and VK-1 derivatives of the Nene, including variants with an afterburner. However, these were all preceded by aircraft, some of which had been Tupolev Type 61 prototypes, which were converted to test captured German axial engines: the BMW 003A (Soviet designation RD-20) and the Junkers Jumo 004B (Soviet designation RD-10). Another 61 prototype was used to test the first Soviet turbojet to fly, the Lyul'kaTR-1, in 1946.