On rack-and-adhesion lines, trains are equipped with propulsion and braking systems capable of acting both through the running rail wheels and the cog wheels, depending on whether the rack rail is present or not. Rack-and-adhesion lines also need to use a system for smoothing the transition from friction to rack traction, with a spring-mounted rack section to bring the pinion teeth gradually into engagement. This was invented by Roman Abt, who also invented the Abt rack system.Roman Abt, Rack-Rail for Railways, , September 21, 1886.
On rack-and-adhesion lines, trains are equipped with propulsion and braking systems capable of acting both through the running rail wheels and the cog wheels, depending on whether the rack rail is present or not. Rack-and-adhesion lines also need to use a system for smoothing the transition from friction to rack traction, with a spring-mounted rack section to bring the pinion teeth gradually into engagement. This was invented by Roman Abt, who also invented the Abt rack system.Roman Abt, Rack-Rail for Railways , September 21, 1886.