Tank transporter A tank transporter is a specialized road vehicle for the transport of tank s , to and from the battlefield or during peacetime . They are necessary to limit the mileage of the tracked vehicles ( as the tracks have a limited lifetime ) and also to reduce wear on road surfaces which can easily be damaged by such heavy vehicles . Tank transporters also use less fuel than tracked vehicles and may have a higher road speed if provided with a good road network . They may also be used for wheeled armoured cars , or for unarmoured tracked vehicles , though the advantages of using transporters are usually less substantial in these cases . Recovery vehicles . Transporters are merely for the " carriage " of tanks . It ' s not their function to recover a damaged , broken - down or bogged - down tank . Specialist armoured recovery vehicle s are used for this , which may have powerful winches or even cranes . Tanks are usually deployed in groups , with groups of transporters to support them . Recovery vehicles are more complex and more expensive to build than transporters , so a handful of recovery vehicles need be supplied to support a troop of transporters . For similar reasons , tank transporters are rarely armoured to recover tanks under fire , although tracked recovery vehicles frequently are . A rare few have been , such as the " Dragon Wagon " of World War Two . In peacetime a main battle tank design will often be produced alongside a tracked armoured recovery vehicle based on the same chassis , so as to have a recovery vehicle available with adequate weight and power for that generation of tanks . In wartime it ' s more usual to recycle the previous generation of tanks as recovery tanks , so as to extend their useful life without using valuable production . Chassis designs . Three chassis designs have been used , generally in this order over time as loads became heavier , although there are exceptions . Rigid chassis . The lighter tanks of the inter - war period were carried on simple rigid flatbed lorries . Trailers . As the weight of tanks became too much for lorry chassis , separate trailers were developed . These carried the entire weight of the tank on their own wheels , putting no weight onto the tractor unit . They are pulled by a ballast tractor connected to a drawbar . The simplest trailer designs have only two axles , but heavier loads frequently require more than this . Multiple wheels per axle are common , usually four , sometimes eight . One advantage of ballast tractors is that they ' re capable of double - heading , where two tractor units are coupled to pull a particularly heavy trailer . Steering . Some designs , such as the 1928 Aldershot design , grouped pairs of axles at each end of the trailer . Others , such as the 70 - ton Cranes trailer illustrated here beneath the " Tortoise " had five axles , spaced along the length of the trailer . The end - wheel designs have the advantages of better ability to cross rough ground and steering more easily . Those with axles throughout their length must have suspension that allows the axles to move and also allowing some steering . This makes them more complicated to manufacture . Placing the wheels at the ends also allows the chassis to dip down into a " well " , giving a lower centre of gravity during transport . The Cranes ' trailer had a frame split into two sections of two and three axles , with a further carrying bed above them . The outermost four axles had Ackermann steering for their wheels . The German Sd . Ah . 116 trailer of World War 2 ( illustrated below . ) went so far as to have steersman ' s position on the rear bogie , covered by the canvas tilt just visible in the background of the photograph . Semi - trailers . The ballast tractor for a drawbar trailer must weigh comparably to its load if it ' s to have traction , which means that the total load might be as much as twice the useful payload . By using a semi - trailer instead , some of the load ' s weight is instead carried by the tractor . This avoids the need for ballasting it , making a greater proportion of the total weight available for the payload . The simplest semi - trailer is " half of a trailer " , having wheels at the rear only and an articulated connection to the tractor unit . A strong metal post or kingpin on the trailer fits into a socket or fifth wheel on the tractor . Semi - trailers cannot be moved on their own , or pushed and pulled by ballast tractors . They are only mobile when connected to the correct tractor unit , which can limit their use in recovery . To keep the load ' s centre of gravity low , gooseneck trailers are used . These have a low horizontal loadbed , with a central spine that rises up at the front to connect to the fifth wheel . As for drawbar trailers , it ' s simplest if all the axles of a semi - trailer are concentrated at the rear , away from the tractor unit . The sheer weight of some though requires more and more axles , and these may then need steering gear at the front . Loading . Ramps . The simplest means of loading the transporter is with a pair of hinged ramps at the rear . The load then drives up and on under its own power . As tracked vehicles exist for their mobility across obstacles , they have no difficulty in doing this . Tilt beds . The Cranes trailer described above uses an entire see - saw tilting bed ( and two small ramps ) . A manual hydraulic pump tilts the empty bed , bringing the loading end close to the ground . The tank drives up , then once past the see - saw fulcrum the bed tilts back under its weight . Demountable axles . Some designs use a demountable axle , where the axle detaches from the bed of the trailer . Access to the load bed is now through low ramps , without needing to climb over the height of the wheels . Again , the intention is to keep centre of gravity low . Power for loading . An operational vehicle can be driven on - board under its own power . This is a delicate operation , particularly with tracks , as their precise steering is limited . In particular neutral steering , where one track goes forward and one backward causing the tank to turn on the spot , is likely to either damage the loadbed or to cause the vehicle to fall off . A few transporters have been fitted with winches for loading , but this is uncommon . More usually a disabled vehicle is loaded with the assistance of a recovery tractor , either winching or pushing it on board .