What improved?
Its cylinders were hidden between the frames. Outside cranks and rods joined the two pairs of driving wheels.
THE ENGINE ROOM / 12
Small parts. Big discoveries.
A little steam. A clever machine. Let’s see what makes it move.
ON THE WORKBENCH4-4-0 · Inside cylinders1903 · 4-4-0 · Inside cylinders
Explore the steam history timeline
3D MODEL
City of TruroShown in green as No. 3440, with outside frames and inside cylinders. The 100 mph claim is presented as disputed, not a confirmed record.
Drag to turn · Scroll or pinch to zoom · Right-drag or two-finger drag to panTap a part to discover it
Ready when you are
FROM THE HISTORICAL RECORD · 1903 · 4-4-0 · Inside cylinders
THE ENGINE’S STORYMeet City of Truro
City of Truro was built at Swindon in 1903. A fast run in 1904 led to a famous claim: had it reached 100 miles an hour? The timing evidence is debated. Historians test claims instead of simply repeating them.
Original, replica or teaching model?
Read the source Shown in green as No. 3440, with outside frames and inside cylinders. The 100 mph claim is presented as disputed, not a confirmed record.
How did life change?
Express trains carried letters and passengers quickly. Railway workers had to keep accurate records as well as look after the machines.
In the archive
Select a photograph to look closer. Captions distinguish originals, replicas and related examples.
Preserved GWR No. 3440 City of Truro in steam.
Ashley Dace · CC BY-SA 2.0Archive record ↗
YOUR NEXT DISCOVERY
Look closer. Have a go. Find out.Think like an engineer.
The speed detective
Become a railway detective. Compare two timing records and decide what they can really prove.
These are made-up practice readings, not City of Truro’s original records. Measure a quarter mile and allow for stopwatch error.
9.0 secondsPossible error: ±.3 secondsPossible speed: 96.8–103.4 mph
Does this reading prove the speed was above 100 mph?
No timer. Try as often as you like. These puzzles explain ideas; they are not instructions for operating a real engine.