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LaunchFive in the hand

Type: Vertical, twin cylinder, double acting, slide valve.
Bore 1 in
Stroke: 7/8 in
Height: 5 1/2 in
Weight: 4 lbs.
Availability 1924-today
Design: 5 column marine engine

Stacks Image 134


Twin Cylinder
Launch Engine.

1 in bore, 7/8 in. Stroke

designed for M.T. Boats
from 5 to 6 feet.

of engine, 5 1/2in, Weight, 4 lbs.

Parts Include.— 1 Cylinder Casting ; 2 Valve Chests ; 2 Covers ; 2 Cylinder Covers ; 2 Cylinder Bottoms ; 2 Crossheads ; 2 Valve Spindle Heads ; 2 Eccentric Sheaves ; 2 Eccentric Straps and Rods ; 2 Connecting Rods ; 1 Sole Plate ; 3 Bearing Caps ; 4 Steam and Exhaust Tee Flanges ; 1 Slide Bar Bracket ; 4 Glande ; All in best Gunmetal.
Sundries.— 1 Cast Steel Crank, with Centering Lugs cast on ; 1 Cast Iron Disc Wheel ; 5 Steel Columns ; 2 Slide Bars ; 2 Sheets Steel for Lagging ; 2 each German Silver Piston an Valve Rods ; 2 Finished Piston Rings ; Steam and Exhaust Pipes ; Hard Brass for Valve Rod Heads.
1 Sheet full size fully dimensioned Working Drawing.

Price, 12s. Post 9d. extra.
Price of Finished Engines, £5 10s. 0d.


All Studs, Bolts, Nuts and Screws, Price 6/-. Four Cylinder Drain Cocks, 5/- Pair of cylinder Lubricators, 3/-.


We also supply this Engine with Compound Cylinders, 3/4in. and 1 1/4in. diameter.
Full set of castings, etc, with Drawing as above, price 13/-, post 9d. extra

Price of Finished Engines, £5 15s. 0d.
Foreign Orders sent carriage forward, unless cost of postage (6lbs. packed) is included in remittance.


Time for something smaller, Stuart now has designed a palm sized twin cylinder marine engine for model boats. This really is a dinky little engine, but has loads of power. The twin cylinder double acting engine has no dead spots so will start at any position of the crankshaft. Early catalogues don't list reverse gear as an option. In 1926 Stuart catalogues illustrate the Compound Launch engine with stephenson reverse gear. It is interesting that in this catalogue the Launch engine is only listed with Gunmetal Cylinder Block and the Compound Launch engine with a choice of either Cast Iron or Gunmetal. Inside information has it that at this time Stuart offered several engines with Gunmetal Cylinders. Whilst gunmetal is much more resistant to corrosion, (Cast iron cylinder engines should be thoroughly flushed and oiled after each run), it is not suitable for use with high temperature Flash Steam. This Gunmetal option does not appear to have been available for long. I am not aware of the date this was withdrawn. I will describe the pros and cons of the compound version in the next review.

Stacks Image 144
Stuart Launch wit reversing gear, counterweights, and a very nice pair of levers to operate the cylinder drain cocks.

Stacks Image 127
Full size Launch engine. Interestingly the valve gear is set between the cylinders.

Video Of Launch Engine.


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