Hover a lever to read its plate · click or press its number to work it
The pulling order
Pasted inside the booking desk lid, in the relief man's handwriting. The frame enforces every line of it — this sheet just saves you learning the hard way.
Coalport → Ferrybridge
Down main, straight through. Points normal.
Ferrybridge → Coalport
Up main, straight through. Points normal.
Milldam → Ferrybridge
Branch onto the down main. Lock out first if 3 stands reversed.
Ferrybridge → Milldam
Up main over the crossover, then the branch. The full pull.
Why it refuses
I The frame
Under the lever handles runs a bed of tappet blades — steel bars notched so that moving one lever drives locks into the channels of others. It is a mechanical proof, built in 1907 and never once argued with: before a signal lever will come, every point it reads over must already stand correct and locked.
Box 12 has eight levers: four home signals, two point levers, one facing point lock securing both point ends, and lever 8 — spare since 1911, and at peace with it.
II The locking
The table below is the box's actual locking table, and it is also the code running this page. Every pull you make is checked against it — the animation never decides anything; the locking does. When a lever refuses, the readout quotes you the row that stopped it.
That is the whole safety argument of mechanical signalling: collisions are not avoided by vigilance, they are made unpullable.
III The evening turn
Seven trains between 17:42 and 18:36 — mains, the Milldam goods, the awkward crossover working, and the evening pair, which will teach you that two roads that cannot meet may lawfully run at once.
Trains are announced by block bell and brought to a stand at your home board. They move when — and only when — you have made their road safe. There is no other way to move them. No collisions tonight. There never are.
| Lever | Function | Pulls when | While reversed, holds |
|---|---|---|---|
| 1 | Home · Coalport → Ferrybridge | 3 R · 4 N · 5 N | 3, 4, 5 as required |
| 2 | Home · Milldam → Ferrybridge | 3 R · 4 R · 5 N | 3, 4, 5 as required |
| 3 | Facing point lock · points 4 & 5 | free | 4 and 5, both ways |
| 4 | Points · Milldam junction | 3 N | — |
| 5 | Points · crossover, up to down main | 3 N | — |
| 6 | Home · Ferrybridge → Coalport | 3 R · 5 N | 3, 5 as required |
| 7 | Home · Ferrybridge → Milldam | 3 R · 4 R · 5 R | 3, 4, 5 as required |
| 8 | Spare | always | nothing, ever |
Track circuits add electric locking on top: while a train stands or runs on a road, every lever of that road is held, whatever the table says. The machine trusts you exactly as far as it can see you.