Coke Ovens and By-Produot Plant in the foreground. ... By these means manual labour is considerably reduced, even pit timber being unloaded by crane. ... The set is complete with an A.E.G. exciter, circulating air and . .oil pumps (see figs. ... This consists of a. pair of vertical inverted two~crank double-acting steam-driven engines, having compound steam cylinders and two-stage air cylinders, the latter anbsp;...