Thornycroft Hathi The Hathi ( Hindi : " elephant " ) was an early four wheel drive lorry built by Thornycroft in the 1920s . It was used by the British Army as an artillery tractor . Development . There was a lack of British - developed four - wheel - drive vehicles developed during the war and no commercial demand for them afterwards . As a result , the Army , under the time ' s general assumption of indigenous sourcing , was forced to develop its own vehicle . The Hathi prototype was developed in 1922 by a team of P Company under Professor ( honorary Colonel ) Herbert Niblett of the Royal Army Service Corps Training College , Aldershot , using parts of a German Erhardt tractor . Production models were built by Thornycroft , 25 being built in 1924 . Although capable for its day , the Hathi was a complex and expensive vehicle that required regular maintenance if the front axle was to remain reliable . For most purposes it was soon replaced by 6×4 lorries with just as many driven wheels , but without the need for the complex combined driving and steering axle . Even half - track s , particularly the Kégresse system , were more popular in this period . Requirements . The first vehicle was built as an experimental prototype , but its success was so great that plans were made to produce them commercially . The specification of requirements was thus drawn up in October 1923 , " after " the prototype had been trialled . These were : Construction . Bodywork of the Hathi was typical for the time with a wide bench - seated open cab and not even a windscreen . The only weather protection was a folding canvas roof . Although the lack of cab was typical for the time , it had also been part of the requirement to maintain a low profile . As for other Thornycrofts the radiator surround was a massive casting ( in aluminium , to save weight ) topped by a brass header tank with the " Thornycroft " name prominently cast into it . A distinctive feature of the Hathi , appropriately giving its elephantine appearance , was the extreme width of the bonnet . The top panels of the bonnet cover were also noticeably concave and are recognisable in photos . Prominent spare wheels were mounted high up , on each side of the rear bodywork . Engine . The engine was a Thornycroft GB6 11 . 3 litre straight - six petrol engine . As was common for the period , the cylinders were cast in two blocks of three . Valves used the " IOE " or " Inlet over Exhaust " arrangement , with overhead valves ( in the head ) for the inlets and side - valves ( in the cylinder block ) for the exhaust . Dry sump lubrication was used , to avoid problems when tilted off - road . To reduce weight , many cast components were in aluminium , rather than iron . Transmission . Four wheel drive for heavy vehicles in this period was difficult and the Hathi used a complex arrangement of bevel gear s to transmit drive through the steering joints of the front axle . Rather than the common system of " articulated " drive shaft s to the front hubs ( the shaft either inside an axle casing or external ) , fixed shafts were used . Shafts inside the axle casing carried power to the ends of the axle , then a bevel gear drove a short shaft running through the steering kingpin . A further bevel on the outer part of the hub carrier ( the part moving with the steering ) drove the hub itself . The constant velocity joint used to make modern articulated drive shafts was unheard of as yet and even the simpler Hooke - type universal joint wasn ' t yet in common use . Thornycroft ' s usual practice for prop shafts at the time was to use a flexible leather disk joint . To save weight , the axle casings were cast in aluminium . Wheels . Production Hathi used single steel disk wheels with 8 studs . The tyres were narrow by modern standards for an off - road vehicle and did not have the exaggerated tread pattern now common , or the bar grip pattern used during the WWII period . To provide a greater grip , typical experiments for the period were carried out , with double wheels and tyres fitted fitted and with cleated tyre chains over these . The doubled wheels used a different wheel from standard , with a greater offset . Drawbar and winch . The Hathi introduced a number of innovations that would become standard on military tractors in later years , including the well - known Scammells . The rear towing draw - bar consisted of a multiple - leaf horizontal leaf spring , spanning the rear chassis rails . This coupled the towing forces directly into the chassis , but also allowed jolts to be cushioned . When winching , the Hathi was fitted with chassis - mounted scotches that hinged down to hold the vehicle in place against the ground . These were stronger than chocking the wheels , quicker to deploy and also carried the winching forces directly into the chassis , rather than through the suspension . These were an innovation of the production Hathi , the prototype vehicle instead having used a precarious arrangement of wheel ramps that lifted the rear of the vehicle off the ground . Experimental developments . 6×6 . A single 6×6 Hathi was produced as an experiment . This was a new build vehicle , with a redesigned chassis . Once again , this was produced by P Company of the RASC Experimental Department . It was tested by the MWEE in May 1928 . Double wheels were used with optional chains . As would later be used on other 6×4 vehicles , the single rear chains spanned both axles . Although successful in its trials , the 6×6 bogie suspension was the victim of its own success . The WD ' s development of its patented rear bogie suspension allowed 6×4 vehicles to be built on a commercial chassis , avoiding the complexity of the Hathi ' s driven front axle . Such vehicles had almost as good cross - country performance as the all - wheel - drive 6×6 , but at lower cost and with the use of mass production commercial lorry factories , not military vehicle specialists . Half - track . The Royal Marines also tested a single example of a half - track Hathi conversion , using tracks by the Roadless company . This was a relatively simple conversion , a Roadless speciality , using the existing rear axle of the Hathi as a combined drive sprocket and road wheel , with a two - wheel bogie and roadwheel idler ahead of this . Service career . Initial production was as an artillery tractor , as at this time the RASC supplied transport to the Royal Field Artillery . Very few Hathi were built , possibly just the original batch of 25 . Use as a breakdown recovery vehicle . In 1926 , at least one Hathi was converted as a breakdown recovery vehicle . A fixed jib with a small hand - operated winch was mounted on the rear deck , with the frame for a canvas tilt over it . Other examples were converted for the RAF and the Royal Navy , a naval example from Portsmouth Dockyard being the survivor today . Australia . Some time in the early 1930s a number of Hathi , possibly seven , were transferred to Australia . Hathi were still in reserve service in Australia in 1945 . Survival today . A single example survives today , in The REME Museum of Technology collection , although it is not on regular display .