Wilson designed and built a ‘Military Car’ in 1906 at Armstrong’s Elswick works. The low-waisted open-top vehicle doubled as a gun tractor or a fighting car mounting a 1-pdr pom-pom beside the driver. Wilson demonstrated its versatility by winching a field gun up and down the steep stone-pitched embankment of the Tyne. This interesting machine attracted little attention and no more were built. Wilson left the company in 1908 to freelance, principally as technical adviser to J. & E. Hall of Dartford where he largely designed the Halford lorry, later widely used in the war. He joined the Armoured Car Division in December 1914.
While Adm Bacon and William Tritton were planning their portable bridging machine that December, Sueter got Messrs Vickers to design a wheeled bulletproof infantry shield. By the end of the month the company had produced a wooden mock-up of a hand-propelled sheet armour screen on a single central wheel which up to 30 men could push ahead of them. The idea was not new and its great weight made it immovable on soft ground, let alone shelltorn terrain. Sueter now recalled Capt Robert Scott’s caterpillar motor sleighs built by the Wolseley Co. for his Antarctic expedition. He had advised Scott on how and where to get the sleighs built. Briggs was instructed to find a similar powered or pushable caterpillar assembly on which to mount the shield.
Lt Lord Tollemache turned up a trade catalogue detailing a small wagon on a full-width chaintrack designed by a perverse genius, Bramah Joseph Diplock of Fulham, West London. Although lacking formal engineering training, Diplock had become interested in heavy traction systems and took out over 100 patents. The first, in 1893, was for a remarkably prescient four-wheel drive steam traction engine with all-wheel steering and pivoting axles for extreme ground conditions. Tasker’s of Andover constructed the machine in 1899. It delivered 50 per cent more hauling power than engines of equivalent weight, encouraging Diplock to produce some highly unorthodox forms of traction. His ‘Pedrail’ wheel comprised a series of elephant-like feet projecting around the wheel’s rim to improve grip and greatly reduce ground pressure. Unfortunately it involved a hideously complex internal assembly of articulated joints, springs, levers and pins almost akin to a scaled-up watch movement. The idea captivated H.G. Wells but few others. Wells wrote the Pedrail into The Land Ironclads in 1903, his prophetic and rather chilling story of the emergence of large invincible armoured fighting machines mounted on Diplock’s big wheels.
Diplock patented a crawler assembly in 1910 which dramatically reduced the friction and power loss of conventional chaintracks. In a fine piece of lateral thinking he stood the principle of the fixed railway on its head. Instead of rolling laden wheels over a pair of continuous rails, he passed two short laden rails over an endless series of rollers. His chaintrack was an inverted railroad. It retained the rather disconcerting feet of the Pedrail, projecting like upturned soup plates around the track’s circumference. The system was ingenious but vastly complicated by a mass of secondary chains, rollers and tensioning springs, promising high wear and constant maintenance. Diplock’s chain tractor and trailer were exhibited at London’s 1913 Commercial Motor Show at Olympia. He was unsuccessful and permanently short of funds, but went on to produce the horse-drawn ‘Colonial’ wagons on a single simplified track which had caught Tollemache’s eye.
Hetherington inspected the little 1-ton truck on 12 January 1915. Next day Diplock demonstrated it at Wormwood Scrubs, laden with 13cwt of stone. His horse hauled it about in deep mud beside the Talbot works and sank to its hocks while the wagon, despite its weight, rode on top of the morass. Sueter bought it for his infantry screen.
Adm Tudor had been an advocate of light armour screens for 20 years and had already submitted his own design to Churchill on 2 January, urging him to order 1,000. His 6ft high and 12ft wide chrome steel shield for 25 men was mounted between a pair of artillery wheels infilled with steel sheet. The 1,000lb device knocked flat for transportation. Sueter conceded its superiority over the Vickers model, but further development lapsed until work on manually propelled and motorized shields was begun by the Trench Warfare Department of the Ministry of Munitions. An experimental version mounted on Diplock’s track and carrying a machine gun was ordered by the Ministry that September.
Naval work on shields was halted by Churchill’s vigorous reaction to Hankey’s Boxing Day memorandum. The First Lord was tired of Kitchener’s recriminations and was now openly contemptuous of military inertia concerning the machine-gun menace. He let the Admiralty loose to develop its own siege-breaking weapon and Sueter caught the blast. On Monday 18 January the First Lord told him that he wanted immediate and substantial trench-destroying experiments to be set in train by the Air Department. He had just ordered construction of the experimental Tritton/Bacon self-bridging machine but he wanted to see other lines of enquiry begun and carried forward at speed. Sueter, heavily preoccupied with aviation matters, recalled Churchill striding up and down the room while dictating a minute to him, punctuated by growls over his shoulder that ‘We must crush the trenches in DAD. We must crush them in. It is the only way. We must do it. We will crush them. I am certain it can be done.’10 That night Churchill minuted Tudor and Sueter:
I wish the following experiment made at once. Two ordinary steamrollers are to be fastened together side by side with very strong steel connections, so they are to all intents and purposes one roller covering a breadth of at least 12 to 14 feet. If convenient one of the back inside wheels might be removed, and the other axle joined up to it. Some trenches are to be dug on the latest principles somewhere handy near London in lengths of at least 100 yards, the earth taken out of the trenches being thrown on each side, as is done in France. The roller is to be driven along these trenches, one outer rolling wheel on each side, and the inner rolling wheel just clear of the trench itself.
The object is to ascertain what amount of weight is necessary in the roller to smash the trench in. For this purpose as much weight as they can possibly draw should be piled on to the steamrollers and on the framework buckling them together. The ultimate object is to run along a line of trenches, crushing them all flat and burying the people in them. If the experiment is successful with the steamrollers fastened together on this improved system, stronger and larger machines can be made with bigger driving wheels and proper protection for the complements, and the rollers of these machines will be furnished with wedge-shaped ribs or studs, which can be advanced beyond the ordinary surface of the wheel when required, in order to break the soil on each side of the trench and accentuate the rolling process.
The matter is extremely urgent, and should be pressed to the utmost. Really the only difficulty you have got to surmount is to prevent the steamrollers from breaking apart. The simplicity of the device, if it succeeds, is its virtue. All that is required is a roller of sufficient breadth and with wheels properly fitted with an unscaleable bullet-proof house for the crew. Three or four men would be quite enough, and as the machine is only worked by night it would not be required to stand against artillery. In a fortnight I wish to see these trials.11
Coincidentally, next day Col Louis Jackson, Assistant Director of Fortifications and Works, received the Tulloch/Swinton proposals. The contrast is striking. On the one hand the Navy Minister, clearly no engineer, was giving a Sea Lord and his Aviation Chief a bare fortnight to set up and complete trials for a land weapon of no relevance to the Admiralty. On the other, and simultaneously, two engineer officers close to the real solution were still struggling to get trials started by the army that so desperately needed the weapon and so determinedly ignored the fact.
Briggs’ engineering assistant, Lt Barry, reported on 20 January:
I have today visited Aldershot and inspected trials made with an American Holt caterpillar. The machine is, I believe, the most efficient form of tractor in existence, and the manner in which it goes over rough ground, soft ground, [etc.] is nothing short of marvelous… With regard to the joining of two steamrollers together, it appears that if this were possible to do, and this machine w
as driven along a trench and did not break in half, the middle wheels would be supported by the outside wheels and it would not have the desired effect of rolling down the trench … steamrollers would be absolutely useless for this as they would immediately become bogged in any soft earth… Any steamroller or tractor would be very hard to armour-plate sufficiently to give protection both to the driver and vital parts of the engine. This also applies to the caterpillar above… The only method for really attacking Germans in their trenches seems to be to have an enormous machine with a plough attachment to it, with a roller behind it, which would walk along the side of the trench, smash in one side and then roll it down flat.12
Barry went on to set up the steamroller trial, coupling a pair of machines side by side and preparing trenches at Wormwood Scrubs. The heavy steamers broke apart three times within yards of starting. Barry continued with one machine. It was driven at top speed at a 2ft high earth bank beside the trench. Having trundled over the damp ground on full power it baulked at the foot of the bank despite the 3in ropes bound round the driving wheels as makeshift strakes. Further attempts ended similarly and experiments were abandoned. Briggs and Barry thought the idea might work if a single giant machine were built 20 times larger than the trials rollers. They had become convinced members of Hetherington’s ‘big wheel’ school and got out drawings of a stupendously proportioned steamer, but Sueter saw its futility and wisely dropped the whole idea of a trench plough or crusher. His report to Churchill concluded:
These experiments prove that the loading of a steamroller is too high for it to be successfully used over agricultural land, and that [for] a machine to perform this work [it] must be specially designed of a greater total weight and with very much greater wheel surface, and particularly much greater diameter wheels. A machine of this description would be very costly to produce and would probably be very difficult to bring into action. Also it could be easily mined.13
Barry’s report was accompanied by a specification for the ‘Revised Hetherington Proposal’. Briggs and Booth had reduced the land battleship to a still awesome 300 tons. Weight would be saved by adopting an open lattice girder frame 46ft high, 100ft long and 80ft wide. Armour 3in thick would protect the vital areas only. The three 40ft diameter wheels would give 17ft of underbody clearance. Top speed was 8mph. Although Sueter’s thoughts were moving away from giant machines he put the proposal to Churchill at the end of January:
It consists essentially of a platform mounted on three wheels (of which the front two are drivers and the stern wheel for steering), armed with three turrets, each containing two four inch guns, propelled by a 800hp Sunbeam diesel set [with] electric drive to the wheels. The engines as well as the guns and magazines would be armoured, but not the purely structural part which would be fairly proof against damage by shell fire if a good factor of safety is used and a superfluity of parts provided in the structure… It can be destroyed by sufficiently powerful artillery [and] by land mines… It would appear at first sight that the machine ought to be more heavily armed and gunned, but considerations of the disproportionate weight of the guns and of time of building have resulted in the proposal being reduced to the comparatively moderate one described.14
Churchill referred the scheme to his energetic and outspoken First Sea Lord, Adm ‘Jackie’ Fisher. Now 73, Lord Fisher had rebuilt the Royal Navy and introduced the Dreadnought class before being recalled from retirement by Churchill in October 1914. Fisher in turn asked Vice Adm Sir Percy Scott, the navy’s gunnery expert, to look into the matter. Scott considered the idea of land battleships deeply flawed because such huge structures would be spotted and wrecked by heavy artillery long before they could be brought into action.
Sueter never had much faith in Hetherington’s wheeled colossus theory. Scott’s reaction persuaded him to drop it, though it was not to die so easily. The hard-pressed DAD was left with Barry’s enthusiastic report on the Holt crawler – supported by Macfie – a hand-propelled sheet armour screen, and an ingenious little tracked one-horse wagon. Churchill was not going to be satisfied with anything less than a large fighting machine. Sueter decided to go for a tracklayer. He asked the War Office for loan of a Holt. They declined, so he turned to Bramah Diplock’s Pedrail.
Sueter’s submarine building experience led him to take a standard Holland class hull and halve its length. The 32ft section with a maximum diameter of 12ft gave him his general dimensions for a lightweight armoured and turreted landship with a moderately upturned bow and stern for a crew of eight. Armament would comprise one 12-pdr or two 6-pdr guns. Briggs calculated the project would produce a machine of 24 tons which was compatible with road-bridge loadings. Each track would be independently driven to give steering. The problem was that they needed a track length of the order of 20ft, far in excess of any yet made. There ensued a frantic search for literature on chain traction. Briggs found a 1911 copy of Scientific American which illustrated a heavy agricultural crawler with fairly long tracks. With these sketchy data they roughed out a design early in February 1915.
Churchill was unhappy with the dismissal of his steamroller idea. Sueter had produced nothing better and the First Lord was looking for a fresh lead from any quarter. It came at an informal dinner party given by his friend the Duke of Westminster at Grosvenor House on 14 February. The two campaigned together during the South African War and the 35-year-old Duke had joined the Armoured Car Division the previous November. Churchill thought him ‘fearless, gay and delightful. Not good at explaining things or making speeches, but he thought deeply … and had unusual qualities of wisdom and judgement. I always valued his opinion.’15 The Duke was enthralled with the experimental work. He had even offered Hetherington the engines from his racing boat Ursula. The dinner was his idea, to give Churchill an opportunity to meet Sueter’s young Turks and hear their views at first hand. Sueter was excluded. Hetherington made a deep impression with his graphic description of the colossus crashing through woods and villages, trampling down trenches and crossing rivers. Here was thinking on a Churchillian scale. The First Lord recalled:
He spoke with force and vision of the whole subject, advocating the creation of land battleships on a scale far larger than has ever been found practicable… I went home determined that I would give imperative orders without delay to secure the carrying forward in one form or another of the project in which I had so long believed… I directed that he should submit to the Admiralty his plans which were for a platform mounted on enormous wheels.16
In Hetherington’s submission to the Tank Awards Committee in 1918 he claimed he did not confine himself to the ‘big wheels’ proposal, saying that he gave Churchill ‘a detailed description of the Diplock caterpillar track which I informed him appeared to give promise of development’.17 Churchill told the Royal Commission on Awards in 1919 that he had no recollection of this: ‘It was a wheel that night that we were talking about.’18
Hetherington’s monolithic approach to the problem matched Churchill’s temperament. (Two and a half years later Churchill was enthusiastically urging the construction of a 200-ton tank ‘wide enough to go down a normal street’.19) He showed Hetherington’s plans to Eustace Tennyson d’Eyncourt, his Director of Naval Construction, asking him if he would take on the design of a landship because its size and complexity equated to shipbuilding. D’Eyncourt was taken aback and asked for time to consider.
Sueter moved quickly. He learned of events at the Grosvenor House dinner party the next day, and instructed Hetherington to arrange a demonstration of the Pedrail Company’s wagon on the following morning, 16 February, in Horse Guards Parade beside the Admiralty. A turreted Rolls-Royce was also to be displayed. Bramah Diplock and his co-director Reginald Brackenbury duly attended at 9am with their draughtsman James Lowe. Sueter persuaded Churchill to come out to see the wagon horse-hauled over the graveled parade ground. Churchill pushed its 33cwt by hand and was astonished at the ease of movement. Sueter put his proposals for building a 24-ton machine on
Pedrail tracks. It was very much a sailor’s concept with its submarine-like prow and Sueter’s explanation that necessary changes of trim on rough ground could be made by blowing water from one end of the machine to the other. Churchill was dubious, saying that it would need an airfield to turn in. Sueter told him that tighter turns could be achieved by locking one track while going ahead or astern with the other. An hour’s earnest discussion followed, during which Sueter proposed the fitting of chaintracks to armoured cars.20 The First Lord returned to his office unpersuaded.
In his memoirs Sueter put a heavy gloss on the outcome of the demonstration. He claimed that Churchill at once saw the superiority of a tracked machine over his own steamroller idea and Hetherington’s three-wheeler. Sueter added that after much discussion the First Lord expressed his satisfaction that the turreted armoured cars could be built on chaintracks, and gave Sueter approval to build 18 landships.21 In fact, Churchill gave no such approval for several weeks, and from that day onward the First Lord effectively relieved Sueter of responsibility for what he called ‘Churchill’s problem’.
Three official attempts had been made to date to find a mechanical solution – the Admiralty’s still untested self-bridging machine, its coupled steamrollers, and the army’s Holt. The first two were hopelessly impracticable, and the day after Sueter’s demonstration on Horse Guards, the Holt trial ended the army’s interest in a fighting chaintrack. Churchill’s hopes now rested on a fresh start with d’Eyncourt and Hetherington. There were no other players on the field. He told the Royal Commission in 1919:
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