What this is

The Steam Engine Works is an interactive museum of the steam engine: seven working engines spanning two centuries, from Newcomen’s atmospheric pump of 1712 to a marine triple-expansion engine of 1912 — the Titanic’s kind. Every engine runs live in your browser — you can tune its design, watch the linkage work, read its instruments, and occasionally destroy it. There is a ten-chapter Primer for newcomers, an Order Book of six period contracts to work through in sequence, a daily engineering challenge with a leaderboard kept in the manner of 1811, and a Gazette that reports your disasters with appropriate solemnity. No accounts, no fees, works on a phone.

The physics is the museum

Here is the thing we care most about: nothing on this site is an animation of what a steam engine should do. Every moving part and every brass number is driven by a small thermodynamic simulation, stepped 240 times a second. Steam is admitted and cut off; it expands along the indicator curve; the area inside the loop is the work of the stroke, and that work — not a script — is what turns the flywheel against the load. Boilers evaporate what the fire allows and vent what the valve permits. Governors droop, as real proportional governors must.

We did not program the Newcomen engine to be feeble or the uniflow to be frugal. We gave each era its constraints — what its boilers could bear, what its valves could do, how much steam its cold cylinder walls stole — and the history fell out on its own: duty climbs from four millions to a hundred and fifty, thermal efficiency from one part in two hundred to one part in six, exactly as the record says it did. When the numbers came out period-correct, we knew the model was earning its keep.

The physics being foundational has consequences we’ve grown fond of. An engine parked at dead centre genuinely cannot start itself — we learned this when ours wouldn’t, and added the bar-over button that real crews used. Screw down the safety valve and the explosion is not a cutscene: pressure simply outruns the venting model until the shell’s limit. And in the daily Trials, your score is computed by re-running the same deterministic simulation — on the server as well, so the leaderboard trusts physics, never browsers.

The machinery behind the machinery

TypeScript, all the way down. The simulation itself is plain, dependency-free functions: thermodynamics with clearance and compression, rigid-body kinematics (Watt’s parallel motion is solved exactly, by circle intersection, not drawn to look right), and a fixed-timestep integrator. The interface is React and Vite; every engine plate is SVG computed as a pure function of the design levers and the crank angle — which is why the drawings reshape themselves when you move a slider. Well over a hundred automated tests pin the physics to steam tables and to the period record.

The site is static, hosted on Vercel, with exactly one small server function: the Engine Reporter, which verifies submitted designs by simulation and files each entry as its own tiny record — append-only, nothing to race over, nothing to hack beyond doing better thermodynamics. There are no cookies and no accounts; the only analytics is an anonymous count of visits.

Who keeps the boilers lit

The Works is built and stoked by Kenneth and Max Ulrich, who set out to make a slider explain the industrial revolution and got carried away. If you find an error of physics or of history, we genuinely want to hear about it — the Gazette stands ready to print a correction. If you beat our duty records, we would rather not hear about it. (Tell us anyway.)

Debts

The bar for this kind of thing was set by Bartosz Ciechanowski’s interactive essays, which we admire enormously. The duty contest follows Lean’s Engine Reporter, which ranked the Cornish engines monthly from 1811 and was the leaderboard before leaderboards. The drawings follow the patent plates and textbook engravings of the period; the cyanotype dark mode follows the drawing offices that copied their plans in the sun. Start with the Primer if the levers baffle you, and take up to-day’s Trial when they don’t.