In this video/article we will examine some rare footage of the Covenanter Bridgelayer in action. The footage is available to watch on the BFIs website and originally comes from the Wessex Film and Sound Archive. The 16mm film was filmed at some time in August 1942 but little else is said about locations in the BFI archive entry for the footage.
The tank’s hull number is visible as T.18434 which I think would make it one of the earliest English Electric-built Covenanters. The covenanter was developed in the late 30s as a cheaper cruiser tank. It entered service in 1940, but saw limited active service – instead being largely used in training roles. The bridge element of the vehicle was a Scissors Bridge 30ft, No. 1. – it was deployed and recovered by a clutch and 2 to 1 reduction gear, it was powered directly from the tank’s engine.
A US report on the Covenanter Bridgelayer explains how it worked:
“The opening of the bridge begins after the launching mechanism has begun to pivot on the rollers of the launching frame. Since the cables are of fixed length, they act to open the bridge as it is pivoted about the rollers. Having been laid across the obstacle, the bridge is disengaged from the prime-mover [the tank itself]. The bridge is then ready for the passage of other vehicles. To retrieve the bridge, the prime-mover crosses the bridge to the far side of the obstacle, hooks up to the bridge, pulls it back to the traveling position, and is then ready to proceed to the next obstacle.”
The bridge had a span of 34 feet and vehicles up to 30 tons could cross it. It could be deployed in under 3 minutes and in total the bridge and the system which launched it was 3.5 tons. The vehicle had a two man crew, with a driver and a commander.
Above is a British Pathe newsreel that gives us a closer look at some of the Bridgelayer’s mechanism at work.
The US report also noted that “In one case 1,200 successful launchings and recoveries were made by one vehicle without undue maintenance.” The system was only mounted on a small number of Covenanters. One source suggests 20 Covenanter I and 60 Covenanter IV tanks were converted into Bridgelayers. Far more Valentines were equipped with them and subsequently the Churchill AVRE became the British Army’s primary bridging tank.
No location is given for the footage but the presence of a number of barrage balloons to the rear is intriguing! It may have been filmed at the Royal Engineers Establishment at Christchurch or at another demonstration elsewhere. Scissor Bridges, with similar basic designs remain in service with numerous militaries around the world today.
The US entered the Great War with no tanks of their own – by the end of the war they had designed and built their first tank, collaborated on a leviathan heavy tank with Britain and built their own copy of the French FT. In this video we look at how the US Army hit the ground running and formed two tank corps and built their first tanks.
In recent videos we’ve looked at all of the US Army’s early tanks, here’s a round up:
The tinny 3-ton Ford was the first American designed and built tank. Aiming to use readily available parts and materials it took inspiration from the French Renault FT but was smaller and lacked the FT’s revolutionary turret. The Ford was only lightly armoured and did have the best cross country handling. Check out our full article on the Ford here.
The MkVIII was a truly ‘international’ effort with the US, UK and France all working on the project. The US and UK provided the mechanical components while France provided a factory to assemble the formidable vehicles. The MkVIII wasn’t ready in time to see action during the war but remained in US service into the 1930s. Check out our full article on the MkVIII here.
The US also sought to produce their own licensed version of the French Renault FT, making some slight changes the tank was adopted as the M1917 but despite production being well underway by late 1918, none of the M1917s reached the front. Instead they became the backbone of the US Army’s interwar tank force. One even climbed a mountain!Check out our full article on the M1917 here.
This is the last of our series of videos/articles on the US Tanks of WWI, you can find all episodes here.
The MkVIII Heavy Tank holds the distinction of being the result of the first successful international co-operative tank project. Developed with input from British and American designers and engineers, intended to be equipped with British weapons and an American engine, with parts made in the US and Britain and to be assembled in France – a truly international undertaking. The MkVIII, sometimes referred to as ‘The International’ or ‘Liberty Tank’, owed its basic design to earlier British heavy tanks but a number of important changes were made.
Intended for introduction in 1919, the war ended before the MkVIII could enter service and even before its French factory had been completed. It did, however, see some production and inter-war service providing the heavy tank backbone of the US’ tank force for many years.
The design evolved from work by British Lieutenant G.J Rackham with later input from American engineer Major Herbert Alden. The MkVIII heavy was very much an evolution of the earlier British rhomboid heavy tanks but Rackham and Alden made some important improvements. Chiefly the redesigning of the tank’s sponsons which housed a pair of British 6pdr guns. While the tank was a foot narrower than its predecessors, the new folding sponsons could enabled the tank to be transported more easily by rail and to also, in theory, navigate narrow spaces. Alden patented this feature in December 1918 (US #1366550). Additionally, the commander’s ‘outlook turret’ positioned on top of the tank’s turret, which had vision slits on all four sides, was also retractable. Alden’s sponsons were hinged at the front and mounted on rolling bearings so they could pivot inwards.
The MkVIII directly addressed several shortcomings of earlier British heavy tanks, firstly the engine was insulated in its own compartment to prevent exhaust fumes overwhelming the crew. A new ventilation system was also added with a fan keeping fumes out of the fighting compartment. Secondly, overall visibility was improved with protected vision and revolver slits and the addition of the tank’s commander’s turret.
Another important design change was the move to longer tracks, about 5 inches in length, which required a dozen less links than the MkV. Each of the links was shallowly stamped to increase its strength. In terms of armament the MkVIII was designed as solely ‘male’ – with guns in its sponsons, not machine guns – however, with a raised tower on the tanks roof this provided positions for five machine guns in hemispherical ball mounts. Two more machine guns could be mounted in the tank’s hull doors located behind the sponsons. The ammunition for the 6pdr guns was held in a central ammunition storage box but the sponsons also had shell storage space surrounding the guns themselves.
The 37 ton tank was to be powered by an American V12 aircraft petrol engine manufactured by the Liberty company. Although a cheaper, water-cooled Liberty was eventually used in the American tanks. The British developed a similar 12 cylinder engine from Ricardo. This, in theory, produced 300 horsepower with a top speed of just over 6mph and a range of just under 40 miles. The MkVIII’s engine was moved from the centre of the tank to a separate engine compartment at the rear of the tank. This not only reduced engine heat and fumes in the fighting compartment but also made communication easier. Some sources also suggest that the MkVIII was the first tank to have an electronic intercom system.
The American Preliminary Handbook for the MkVIII listed the tanks as being equipped with 7 ‘Hotchkiss .303-inch machine guns’, these are likely to be Hotchkiss Portative MkI*s popular in British service. In US service, however, the tanks were likely later equipped with the new Browning M1919 Tank Machine Guns. The tank carried 182 rounds of 6pdr ammunition and an additional 26 smoke rounds as well as 21,000 rounds of machine gun ammunition to keep the 7 machine guns fed.The tank’s armour was also increased lightly from the previous MkV, with 16mm of frontal armour and between 10 and 12mm at the sides. Less vulnerable areas had armour 6mm thick.
The American MkVIIIs were initially planned to be manned by an eleven-man crew made up of a driver, commander, two gunners and two loaders to man 6pdrs, four machine gunners and a mechanic. Later crew complements probably dispensed with two of the machine gunners as the US MkVIIIs operated during the inter-war period dispensed with two of the midships machine guns. The British crew was planned to be smaller with 8-men fighting the tank, made up of a driver, commander a pair of gunners and loaders for the main guns and two machine gunners who were tasked with manning the tank’s various machine guns. Impressively the 34 feet long tank also had room for as many as 22 infantry to be transported.
As an allied collaborative project the production of parts was to be a collaborative effort. Britain was to contribute armour plate, structural frame work and armament. The American contribution was to include the automotive parts including the engine, brakes, drive sprockets, gears and transmission.
The French were largely uninterested in British heavy tanks and their primary contribution to the MkVIII project was a factory site near the village of Neuvy-Pailloux, 165 miles south of Paris, in central France. Critically located well away from the fighting on a main rail route north, through Issoudun. Construction of the impressive factory appears to have begun in early 1918, with the framework of seven long production halls and the installation of a powerplant and generators and the building of railway sidings completed before the armistice in November 1918. Production barely got underway in Britain, let alone in France. Contemporary photographs taken in January 1919, by the US Army Signal Corps show the factory with its roof in various stages of completion, its shop floors unfinished and empty and open to the elements. The factory would eventually be completed and used by the French army as an artillery park and later a maintenance depot.
The oringal plan was for the tank parts to be shipped across the channel and the atlantic through France’s western coastal ports to be shipped by rail to Neuvy-Pailloux where they would be assembled into working tanks. It was envisaged that the workforce would be made up of Chinese labourers with British and American foremen and managers.
As many as 3,000 tanks were planned for 1919. The British intended to build 1,450 MkVIIIs of their own use in addition to the 1,550 to be produced for general allied use. The British tank parts were to be manufactured in Manchester, by the various workshops of the Manchester Tanks Association, and in Glasgow, by the North British Locomotive Company. Mass production in Manchester never got underway and the initial British MkVIIIs were built in Glasgow – just 24 are believed to have been built, all but six of these were scrapped almost immediately. The first American tanks were assembled by the Locomobile Company of Bridgeport, Connecticut. The American-assembled MkVIII completed acceptance trials in the spring of 1919. With the end of the war the US order was reduced from 1,500 to 100. 100 sets of hull components were bought from Britain and assembled with corresponding American parts at the Rock Island Arsenal.
The MkVIII was the last of the British rhomboid heavy tanks. The handful of British MkVIIIs built never entered service but the 100 American tanks along with American built M1917s, MkV Heavies and Renault FTs brought back from France, formed the backbone of the US Tank Corps throughout the early inter-war period. The US MkVIIIs remained in use as training tanks until 1932. Today, just three are believed to survive; two in the US and one in Britain.
More of a gun carrier than a tank, as the vehicle was open topped, it was, however, equipped with a 75mm field gun. During the footage it not only seamlessly operates on both land and water, it also fires four rounds as it crosses a body of water at the Aberdeen Proving Ground.
Very little is known about the vehicle but it is believed to be the second of three amphibious vehicles developed by Christie during the 1920s. None of the vehicles were purchased by the US military and no major international orders were made either.
The vehicle itself is manned by two people during the demonstration, presumably one steering while the other mans the gun. It appears to have narrow tracks over its four sets of wheels and a pair of propellers at the rear.
Demonstration of Ordnance Materiel at Aberdeen Proving Grounds, 1920-1926, US National Archives, (source)