A colliery tub is taken up an incline (see figure) by means of a long link chain with special attachments which engage with the axle of the tub, and thus convey it up the incline. The endless chain travels over two polygon terminals, one of which is fitted with tightening gear. There are many similar devices. The one here illustrated is manufactured by Messrs Coulson & Co. Ltd., of Spennymoor.