Wheelset (rail transport)

Four-wheeled goods wagons that were once near-universal in Europe and Great Britain and their colonies have only two wheelsets; in recent decades such vehicles have become less common as trainloads have become heavier.

Abnormal wear at the wheel–rail interface is thus avoided,[1] along with the loud, piercing, very high-pitched squeal which usually results from it – especially evident on curves in tunnels, stations and elevated track, due to flat surfaces slipping and flanges grinding along the rail.

However, if the degree of conicality is inappropriate for the suspension and track, an unpleasant oscillation can occur at high speeds.

Recent research is also showing that marginal changes to wheel and rail profiles can improve performance further.

[3] Australia's Queensland Railways used cylindrical wheels and vertical rails until the mid-1980s, when considerably higher train loads made the practice untenable.