Tranent - Cockenzie Waggonway

BBC iPlayer has a recent archaeology programme with a section on Scotland's first railway, a 1722 waggonway which carried coal from Tranent to salt pans at Cockenzie.    View Digging for Britain series 9 episode 3, from about 28 mins in.   (Stills below are from this episode.)

On the route of the waggonway

An artefact from a large horse

On the archaeological dig for remains of the 1722 Tranent-Cockenzie waggonway,
with which the Tanfield waggonway has several similarities