Definition of "wheelbase"

Beneath the snow, and after we had left it behind, the road was as greasy as vaseline, as steep as a scenic railway, and often not a yard wider than the lorry’s wheelbase.

1937, Robert Byron, “Kala Nao”, in The Road to Oxiana‎

The Southern acquired them because the little Class "B4" 0-4-0 tanks were finding heavy modern rolling stock more and more of a handful, and at war's end the railway had nothing of suitable power but short wheelbase on its books to take their place on the more tortuous of the dock lines.

1959 February, G. Freeman Allen, “Southampton—Gateway to the Ocean”, in Trains Illustrated, page 91

He thought the types of wagons planned (short-wheelbase types) needed reassessment.

2023 March 8, David Clough, “The long road that led to Beeching”, in RAIL, number 978, page 42