Monorail Sled: Two Tandem Plank Runners Shod With Strap Iron, Steered Lying Down (Boy Mechanic, 1915)

"Round iron or half-round iron should not be used, as these are liable to skid. The square, sharp edges of the strap iron prevent this and grip the surface just as a skate."

Cut the two runners from 1 in plank to the size and shape of his sketch: the front runner 2 ft long, the rear one 2-1/2 ft long and about 1 ft high (the sketch prints the rear length with an inch mark; it is drawn as 2-1/2 ft). Shoe them with strap iron 1 in wide and 1/4 in thick, keeping the edges square and sharp.

Nail or bolt blocks on either side of the upper edge of the rear runner and screw the top board (6 ft long, 1 in thick) to them. Brace the runner with strap iron, as in the sketch.

Fit the front runner the same way, but with only one pair of blocks at the centre and a thin piece of wood on their tops as the fifth wheel. Bore the hole for the steering post 6 in from the front end of the top, a little larger than the post. Round the post where it passes through the hole and leave its upper end square, to take the steering bar tightly.

From "How to Make a Monorail Sled" by Harry Hardy, in **The Boy Mechanic, Book 2**, Popular Mechanics, 1915 (Project Gutenberg 44585; checked on the archive.org scan boymechanicbook200chic2, p. 50). The rear runner length is printed 2-1/2 with an inch mark but drawn longer than the 2 ft front runner, so it is read here as 2-1/2 ft. He gives no sizes for the blocks, braces or steering bar. The tools and metric figures are ours.