sentences:  Due to a failure at the Department of Railways New South Wales power station at Zaara Street in Newcastle in July 1941 the Department of Railways constructed a transmission line to join with the overland transmission line to Cessnock to allow Cockle Creek to supply power to the Railway's transmission grid.With increased demand for power during the 1950s a fourth boiler was ordered.This boiler was also built by Babcock & Wilcox and was a bi-drum radiant type water tube boiler and ran at a steam pressure of with a capacity of of steam per hour and was fed by a single Babcock "Detroit" Rotograte stocker.