Mystic in Stonington in Southeastern Region, Connecticut — The American Northeast (New England)
Compound Steam Engine
From Tugboat Socony 5
Photographed by Michael Herrick, August 26, 2013
1. Compound Steam Engine Marker
Horsepower: 850
Cylinders: 2
Bore: 19, 40
Stroke: 28
Weight: 40,000 pounds
Length: 8 9
Width: 6 10
Height: 14
This large steam engine was built in 1927 by the Staten Island Shipbuilding Company in Staten Island, NY. It turned a 10-foot-diameter propeller on the steel tugboat Socony 5, part of a New York Harbor tugboat fleet owned by Standard Oil Company of New York.
Developed about 1870, the compound two-cylinder engine was a practical power plant for small to medium-sized vessels for almost 80 years until superseded by diesel engines. This example worked with a steam pressure of 160 pounds per square inch. Steam from the boiler first entered the small high-pressure cylinder, driving its piston, and was then exhausted into the large low-pressure cylinder to expand further.
The engines horsepower of 850 may seem modest by todays standards, but this figure is based on a working load output, unlike horsepower calculations for modern internal-combustion engines. This engine has 10 times the horsepower of the Paine compound engine of the Museums passenger steamboat Sabino.
Erected by Mystic Seaport Museum. (Marker Number 1993.153.)
Topics.
this page online
Location. This marker has been replaced by another marker nearby. It was located near 41° 21.571′ N, 71° 57.889′ W. Marker was in Stonington in Southeastern Region, Connecticut. It was in Mystic. It could be reached from the intersection of Greenmanville Avenue (Connecticut Route 27) and Bruggeman Place, on the right when traveling south. Located in Mystic Seaport. Touch for map. Marker was at or near this postal address: 75 Greenmanville Avenue, Mystic CT 06355, United States of America. Touch for directions.
Regionally, this marker was on the Connecticut Shoreline, in Greater New London, in Mystic and the Eastern Shore, and in the Thames River Valley. It was also in the American Northeast and in New England. Globally, it was in the North Atlantic Region, North America, the Western Hemisphere, the Western World, and the Anglosphere. Historically, it found itself in what was once New London County and also one of the original Thirteen Colonies.
Other nearby markers. At least 8 other markers are within walking distance of this location: A different marker also named Compound Steam Engine (here, next to this marker); a different marker also named Live Oak Log (a few steps from this marker); Atlas (a few steps from this marker); Fish Flake (a few steps from this marker); Wolverine Semi-Diesel Engine (within shouting distance of this marker); L.A. Dunton (within shouting distance of this marker); Restoring the L.A. Dunton (within shouting distance of this
Photographed by Michael Herrick, August 26, 2013
2. Compound Steam Engine
Other markers no longer nearby. Live Oak Log (was a few steps from this marker but has been replaced with another marker now near it); Wichmann Semi-Diesel Engine (was a few steps from this marker but has been permanently removed); Lathrop D-90 Diesel Engine (was within shouting distance of this marker but has been permanently removed).
Related marker. Click here for another marker that is related to this marker. This marker has been replaced with the linked marker, whose inscription is slightly different.
Also see . . . Mystic Seaport, The Museum of America and the Sea. (Submitted on September 15, 2013, by Michael Herrick of Southbury, Connecticut.)
Photographed by Michael Herrick, August 26, 2013
3. Compound Steam Engine
Photographed by Michael Herrick, August 26, 2013
4. Compound Steam Engine
Photographed by Michael Herrick, August 26, 2013
5. Detail Photo on the Marker
Photographed by Raymond Eckhoff
6. Model of Tugboat Socony 5
http://www.aukevisser.nl/mobil/index.htm
Credits. This page was last revised on May 19, 2026. It was originally submitted on September 15, 2013, by Michael Herrick of Southbury, Connecticut. This page has been viewed 1,051 times since then and 30 times this year. Photos: 1, 2, 3, 4, 5. submitted on September 15, 2013, by Michael Herrick of Southbury, Connecticut. 6. submitted on September 18, 2013, by Michael Herrick of Southbury, Connecticut.
