Green’s Dictionary of Slang

carts n.¹

[? echoic of the sound of a labourer’s heavy, boot-clad step, or ? cart n.¹ (2)]

a pair of shoes.

1860		Hotten Dict. of Modern Sl. etc. (2nd edn).
1873		Sl. Dict.
1909		J. Ware Passing Eng. of the Victorian Era.
1935		A.J. Pollock Und. Speaks.