A 1970s-era advertisement for the H.J. Coventry 1/3HP Marine Compound engine. This engine was designed in 1929 and has not been produced, or available, since the 1970s.
Mr. Coventry's ORIGINAL marine engine (built 1929), "live and in color".
In 1929, H.J. Coventry designed (and made castings available for) a vertical, stationary marine engine, 1/3rd HP, 2-cylinder, compound style. Its construction was described in The Modelmaker magazine at that time, and castings advertised in same.
It was described again to a new audience in the 1950s in The Miniature Locomotive magazine, and again to yet another audience in the 1970s in a series of articles that ran for a time inLive Steam Magazine.
Castings have been unavailable since the 1970s.
Most of the castings for the "1/3 HP Compound Engine".....enough to build the engine....are available again, and are shown here. The is the first time in almost a half-century, that they've been produced.
Castings for the H.J. Coventry 1/3 horsepower, compound marine engine. It has been 95 years since this design was first produced, and has been nearly 50 years since castings were last available. Note the dime (USA 10-cent coin) at the center of the photo, for size reference.
Castings
Low-Pressure Cylinder
High-Pressure Cylinder
Low-Pressure False (valve) Face
High-Pressure False (valve) Face
Low-Pressure Steam Chest
High-Pressure Steam Chest
Low-Pressure Steam Chest Cover
High-Pressure Steam Chest Cover
Low-Pressure Cylinder Cover
High-Pressure Cylinder Cover
Low-Pressure Piston
High-Pressure Piston
Low-Pressure Piston Bull Ring
High-Pressure Piston Bull Ring
Bedplate
Back Columns
Main Bearing Cap (Center)
Main Bearing Caps (Fore & Aft)
Main Bearings
False Stuffing Boxes
Eccentrics
Eccentric Straps
Eccentric Rods
Flywheel
Specifications:
1-1/4" and 2-1/4" bores, x 1-1/2" stroke
Compound....exhaust steam from the high pressure cylinder, powers the low-pressure cylinder
Slide Valves
Stephenson valve gear, reversed via hand wheel with worm gear
Develops 1/3 HP at about 600 RPM
All parts can be handled on a 9" lathe, and a small bench-top mill or mill/drill
Click the button at right, to purchase the complete set of drawings, and the construction articles, for the H.J. Coventry "Marine Compound" engine. $140.00, plus $35.00 shipping.
(For shipping to countries other than the USA, please inquire).
Click the button at left, to purchase the currently-available castings for the H.J. Coventry "Marine Compound" engine. $3,995.00, plus $75.00 shipping.
(For shipping to countries other than the USA, please inquire).
The remaining castings will be ready in 2024, and may be purchased at that time.
Another example of the 1/3 Horsepower Compound Marine engine by H.J. Coventry; this one by a different builder and featured in Modeltec Magazine some years ago.
