Bauer-Wach Exhaust Steam Turbines *

In 1927–8 two cargo ships of roughly 11,000 tons displacement were built by Messrs. R. and W. Hawthorn, Leslie and Company for the Booth Steamship Company of Liverpool. Originally of identical design, the plans of S.S. Boniface were altered during construction to include a Bauer-Wach exhaust steam turbine, whilst S.S. Basil was built as originally designed with a triple-expansion engine only. Builders' trials on S.S. Boniface proved the turbine to give a reduction in coal consumption of 24·5 per cent.

The paper adds to the facts already known about this type of installation some information regarding reliability and economy in actual service. Following a general description of the propelling machinery and auxiliaries of the two ships, and a more detailed description of the exhaust steam turbine, gearing, hydraulic coupling, and control system of S.S. Boniface, notes are made regarding the general running and the troubles experienced with the extra equipment. Particulars of two trials at sea under normal conditions on S.S. Boniface are given, and finally, a coal consumption comparison on a yearly basis between the two ships is shown to give a saving of 15·9 per cent in favour of S.S. Boniface at the age of four years.