Print Friendly, PDF & Email

While the technology of cannons and protective materials had already shown a certain degree of maturity at the beginning of tank development, pioneering work still had to be done in the areas of compact motors, steering gears and chassis.

Accordingly, the constructions initially had many problems in spite of a simple design and low performance. It must be all the more surprising today what a remarkable advancement these assemblies have undergone in the relatively short period of a good 100 years.

Tasks and requirements for crawler tracks

The chassis of military tracked vehicles must meet important requirements:

  • Traction: absorption of weight forces and implementation of propulsion, braking and lateral forces on the ground,
  • Cross-country mobility and overcoming obstacles: Achieving the highest possible speed in the field (e.g. to negotiate visible distances) and overcoming critical floors and obstacles and
  • Reduction of shocks and vibrations as well as noise to protect the crew and components.

In detail, the aforementioned basic requirements result in a large number of further requirements. For example, there are also aspects of system compatibility / integrability and material maintenance as well as technical and economic aspects, which, however, would go beyond the scope of this article.

History / development lines

As expected, the first chassis were characterized by very simple designs. The undercarriages of the first British tanks were even unsprung, which resulted in a high load on the crew when driving off-road, even if the maximum speed was only six km / h. With the first undercarriages, the primary design goal was to fulfill the basic functions and achieve a certain reliability and service life. Performance aspects played a completely subordinate role.

Basic design of the "Christie", recognizable is the independent wheel suspension and suspension by long-stroke coil springs (source: author)

However, the first vehicles with spring-loaded castors appeared relatively quickly - initially they were often composite systems with balance beams. Chassis designs by US inventor Walter Christie showed a first major advance in the early 1930s.

Christie proposed a single wheel suspension using long-stroke coil springs. This enabled his armored vehicles to reach top speeds of up to 68 km / h on firm roads (and up to 120 km / h with the chains removed). These were revolutionary performance values ​​for the time. While W. Christie itself was unsuccessful with its vehicles in the USA, Great Britain and the Soviet Union adopted its chassis concept. The suitability of the concept was proven until the 1940s with the Comet cruiser tanks and the T-34.

Print Friendly, PDF & Email