Engine description
Vital Statistics:
Length: 85′ Beam: 19.5′ Draft: 12′ Tonnage: 91 t Hull: Wood Power source: 332 IHP; triple-expansion steam engine, oil. Originally built for the Royal Navy, the engine was purchased post WWI as army surplus. Master is the only wooden steam operated tug that survives today. The tug Master was built by Arthur Moscrop in 1922 at the Beach Avenue Shipyard in False Creek, where the Vancouver Aquatic Centre is today. Moscrop was a well-known tugboat builder and designer, and over saw the building of the RCMP Schooner, St. Roch.
Built in 1922, in False Creek, Vancouver, by Arthur Moscrop, the MASTER is the last remaining example of a once formidable fleet of wooden hulled, steam powered towboats on the West Coast
The MASTER displaces about 200 tons, is 85 feet long, 19.5 foot beam and draws 12 feet of water. Her triple expansion steam engine was built for the Royal Navy in 1916. Turning an 8 foot diameter propeller at 100 r.p.m., today she cruises at @ 7 knots.
When working, She used to carry a crew of seven, 3 Engine Room Crew, 2 Deck Hands and a Captain & 1st Mate, however She has bunks for nine. Fueled with bunker oil held in an original steel riveted 10,0000 gallon tank ( cut down to 6,300 gallons now ), just forward of the boiler, She used steam about 2,0000 miles with one fill of fuel in the tank, but now with the top 2′ of the fuel tank removed during a recent refit the steaming range has been somewhat reduced. When raising steam from cold, it takes two days, as the boiler has to be “warmed through” slowly to prevent stressing the fire tubes etc.
SS Master’s Triple Expansion Double Acting unit was built in 1916 by William Beardmore’s Speedwell Iron Works Co. in Coatbridge, Scotland. It was built for the Royal Navy for installion in a First World War Minesweeper that was ordered but never completed. The diameter of the cylinders are as follows; High Pressure (HP) 9.625″, Intermediate Pressure (IP) 15.5″, and Low Pressure (LP) 26″. The stroke is 18 inches and the indicated horsepower is 332.
Scotch Marine, two pass, fire tube boiler…This current boiler was built in 1945 and re-tubed in 1984. The smoke box doors were made by BCIT students.
A fire tube boiler is basically a cylindrical shell, or drum, with a top and a bottom plate and the tubes passing between; under full pressure and usually holding a large quantity of water. Thus it holds a great energy reserve in the heated water, permitting steady steaming even with fluctuations in the fire. A fire tube boiler is slow to raise steam, holds great potential in the large mass of stored energy and a lethal explosion can occur if not properly maintained by Engineers. It is however, easier and cheaper to build and, if constructed to ASME code standards, fully as safe as a water tube boiler.
