Sentence:  Having had a precursor in the tracks ground into Roman roads (with a width similar to modern standard gauge, 1435 mm or 4ft 8.5in), Europe only saw the return of track systems in the early modern age, in the shape of mining railways: wooden <WSD>lorries</WSD>, operating on wide wooden rails and guided by a track nail between the two rails. 
Meaning of the word marked with <WSD> tags:  A small cart or wagon used on the tramways in mines to carry coal or rubbish.