The T20 used an early version of the horizontal volute spring suspension ( HVSS ), another improvement compared to the less robust vertical volute spring suspension ( VVSS ) of the early versions of the M4.
12.
The T20 used an early version of the horizontal volute spring suspension ( HVSS ), another improvement compared to the less robust vertical volute spring suspension ( VVSS ) of the early versions of the M4.
13.
The Sherman's reliability resulted from many features developed for U . S . light tanks during the 1930s, including vertical volute spring suspension, rubber-bushed tracks, and a rear-mounted radial engine with drive sprockets in front.
14.
Late World War II American designs replaced VVSS with a version of the Horstmann suspension that replaced its coil springs with the volute springs from the earlier VVSS . This was a major feature of the M4A3E8 model " Easy Eight ", so known due to its smooth ride.
15.
Within each different prototype series, a variety of different suspension and armament configurations were tried out, for example, the T20 had an early version of the horizontal volute spring suspension ( HVSS ) suspension later employed on the M4A3 Sherman, whereas the T20E3 had torsion bar suspension.
16.
The M4A3 was the first to be factory-produced with the HVSS ( horizontal volute spring suspension ) suspension with wider tracks to distribute weight, and the smooth ride of the HVSS with its experimental E8 designation led to the nickname " Easy Eight " for Shermans so equipped.
17.
A design for the tank had been established, however it was subject to a redesign to alter the internal stowage, and include new features not previously considered such as removal of the turret basket, addition of a gyro-stabiliser, and swapping a hydraulic traverse for the electrical system, and torsion bar suspension for the volute spring used up until that point.
