During development of the Spoornet HS self-steering bogie during the early 1970’s, various materials were tested for the four cross anchor pivot points (also known as stabilisation points)

The material required the following characteristics :

• Wear resistance
• High compression strength
• Dimensional stability
• Low water absorption

After extensive testing Vesconite was accepted as the material which best satisfied the requirements of the application and has been used for 25 years on the HS bogie.

Vesconite ensures a slow wear rate on the bush. This is essential to the continuous alignment of the bogie and to facilitate the desired low contact force (lateral force) between wheel and rail. The cross anchors are important to the optimum stabilisation of the bogie during high speed operations. Vesconite has proved itself as the bearing material of choice in the stabilisation points.

Vesconite is fitted to the following self-steering bogies - Mk III, Mk V, Mk VII, Mk VIII and MK XI. Approximately 54 000 of these bogies are presently on service on Spoornet lines.