About Hammer Blow!

This is a free, open-source game for kids about steam locomotives.

The game features data from a hand-drawn 1938 engineering page titled "Proposed Garratt". Garratt locomotives are huge articulated steam engines. The 1938 drawing worked out how heavy a balance weight you would need to bolt onto the driving wheels to stop them pounding the rails to bits at speed. That pounding has a real name: dynamic augment, sometimes called hammer blow.

The numbers in the game come straight from the 1938 sheet. At speed v in mph, the balance weight is W = 610,456 ÷ v² pounds. The percentage balanced is W ÷ piston_weight × 100. The 13 levels use speeds from 30 to 90 mph in 5-mph steps and piston weights of 900 to 1200 lb, exactly as listed on the original drawing.

Source drawing: "Proposed Garratt", dated 10 March 1938. Driver wheels 5'10" diameter, 28" stroke, 2½ ton target dynamic augment.

Open source: MIT licensed. Fork it, change the colours, add characters, make it yours.