Ice Boat: Crossed Timbers, Skate-Edged Runners, Bicycle-Fork Steering and a Gaff Sail (Boy Mechanic, 1915)

"In constructing the ice boat, use two poles, or timbers, one 16 ft. and the other 10-1/2 ft. long, crossed at a point 2-1/2 ft. from one end of the longer timber. The crossed pieces are firmly braced with wires, as shown."

Cross the 10-1/2 ft timber over the 16 ft one, 2-1/2 ft from its front end, and fasten them firmly. Brace them with wires as in the drawing: from the bow to points on the cross timber, and from the cross timber back along the long one. The drawing puts the wire points 6 in and 1 ft 6 in from each end of the cross timber.

Cut two band-iron strips 18 in long, 3 in wide and 1/8 in thick; grind one edge like the edge of a skate and round the ends. Bolt each to the side of a wood piece 18 in long, 6 in wide and 2 in thick, so the ground edge projects about 1 in. With a pole frame, bolt each runner block at right angles to a 12 in piece of wood shaped as drawn, the bolts running diagonally through its shouldered part; the pole end rests on this and is bolted down. With squared timbers, fasten the runners straight to them.

Fasten the rear runner between two pieces of wood so its edge projects, and clamp it in a bicycle fork cut down to leave about 3 in of the blades. Bore a hole through the rear end of the long timber for the fork head. Fit a lever (5 ft on the drawing) to the top of the fork head: bore a hole through the lever end at a slight angle to fit the head, slot the end, bore across the width of the handle and put in a bolt as a clamp.

Cut a mortise in the long timber 15 in from the front end and set the mast in it; stay it with wires as drawn. His text says the mast should be about 12 ft; his drawing marks it 14 ft 0 in: choose one and keep the sail to suit. Fasten a board on two crosspieces mortised into the top of the long timber, as a seat for the driver (5 ft long on the drawing, ending 2 ft 3 in from the stern).

Make the sail of any good material to his drawing: luff (along the mast) 9 ft 0 in, head 4 ft 8 in, foot 11 ft 0 in, leech 12 ft 6 in. Hang the main boom, 11-1/2 ft long, and the upper spar on the mast "in the usual manner". The text also names a jib boom of about 6 ft, which the drawing does not show.

From "An Ice Boat and Catamaran" by Robert K. Patterson, in **The Boy Mechanic, Book 2**, Popular Mechanics, 1915 (Project Gutenberg 44585; checked on the archive.org scan boymechanicbook200chic2, pp. 27-28). His text and drawing differ on the mast (about 12 ft against 14 ft 0 in) and on the jib boom, which is in the text only; both are stated, not resolved. He gives no timber sections, wire size or sail cloth: those choices are ours, as are the tools and metric figures. The summer catamaran conversion is not made here.