English: Opportunities to visit steam turbine powered ships are now few and far between and the recent scrapping of older passenger tonnage due to stricter SOLAS regulations has not helped. SS Margaret Hill was a liquefied natural gas carrier with the boilers fired on boil-off gas (BOG - yes really). The vessel was built in 1974 by Moss at Stavanger, Norway and fitted with a General Electric cross compound steam turbine of 30,400 horsepower and good for 19.5 knots.

This view is low down in the cavernous machinery space just in front of the main surface condenser. All steam has some entrained incondensable gas and this needs to be removed by an 'air pump'. Reciprocating steam engines and small old turbines had a reciprocating pump that removed both condensate and 'air'. Large surfacing condensing turbines has a centrifugal pump to remove condensate and one of two methods of removing air. Many plants had steam jet air extractors but Margaret Hill had motor driven liquid ring (Nash type) pumps that are seen here. These are the only examples I've ever seen and I had to specifically ask how the air was handled as they were well hidden.