8.4.4 Types of wheel

Most modern trolleys are fitted with wheels having a tread profile which is suitable to run on any standard constructional section flange or for a specific profiled track section. Older trolleys and those for certain applications may have wheels with tread profiles to suit a specific flange sections, e.g. tapered flange RSJ. The more common trolleys have wheels with a plain bushed bearing. For special applications and for higher loads anti-friction bearings are available.