If a wheel slip occurs in a tram during start-up, you must stop, and then:

Wheelspin when moving off indicates a loss of traction, caused by too abrupt a delivery of power. Ceasing this action and moving off again more gently allows the driving force to be matched to the conditions and for traction to be regained. This procedure ensures the vehicle moves off smoothly and effectively, while also preventing damage to the wheels and rails.