Three Cylinder Trunk Marine Engine

[Mike Serpa]

I have no idea what this is but thought some here might be interested.

More at the link. Arrow right to page 74-75 for more drawings of this engine.
Drawings of Annular Cylinder Engine for Screw Propulsion on page 153. I guess that for marine use?

The Practical Mechanic's Journal. 1858. Page 30.
https://archive.org/stream/practicalme2318581859glas#page/n49/mode/2up

 

[AndyHall]

The note indicates an engine of this type was fitted to the steamer Armenian:

Length (feet) : 209.5
Breadth (feet) : 32.0
Depth (feet): 20.5
Gross Registered Tonnage (g.r.t.) : 944
Net Registered Tonnage (n.r.t.) :
Engine Type : 60hp
Engine Builder : T Richardson & Sons
Additional Particulars : Iron passenger/cargo ship; 3 bulkheads. Originally built as a sailing ship she was converted to steam & converted back to sailing in 1870.

Wrecked at Madras, 1872.

 

[JohnDLittlefield]

Converted back to a sailing vessel is suggestive. Must be a story there.

 

[georgew]

Converted back to a sailing vessel is suggestive. Must be a story there.

Trunk engines were frequently used to keep the mechanisms below the waterlines of military vessels. The largest run of this type engine was done in Britain for the Crimean gunboats in the mid to late 1850's, driving single propellers. Because of a problem with the use of green wood in their construction, a large number of these gunboats were sold off and dismantled during the mid to late stages of the Civil War. There were 20, 40 and 60 nominal hp rated versions built by two separate suppliers to a single specification. This is the first time I'm aware of where parts interchangeability between two manufacturers was part of the design specification. They were busy little high-pressure versions and required good mechanics. To estimate their indicated hp, multiply the nominal rating by about 4.5. The British later built a series of twin engine gunboats and recycled these engines with great success. Later applications of the "war surplus" versions were used with condensers to improve fuel economy. A complete engine of this type has been recovered in Australia from a commercial vessel that sank in shallow water. The Australian team has patiently removed the concretions over a number of years and the result is a very interesting engine. The trunk engines went the way of the Dodos when vertical multiple expansion engines took over. I've done a bit of studying these engines and formed an opinion that the Confederates really missed an opportunity by not investing in a British salvage company dismantling some of these gunboats. It would have been a source of complete "low mileage" power trains including boiler, engine, drive-shafts and propeller built for each other. Put two of them into a Confederate built hull and you have a twin-engine gunboat with about 480 hp total. Of particular interest is the fact that the lower hp-rated versions of these engines were used on propeller gunboats that could run in 4 feet of water.