The Thorpe rail accident occurred on 10 September 1874 when two trains were involved in a head-on collision at Thorpe St Andrew, Norfolk, England.^{[1] [2]}

Thorpe rail accident
Details
Date	10 September 1874 21:45
Location	Thorpe St Andrew, Norfolk
Country	England
Line	Norfolk Railway
Cause	Single-line telegraphic working error
Statistics
Trains	2
Deaths	25
Injured	75
List of UK rail accidents by year

The accident occurred on what was then a single-track rail line between Norwich Thorpe and Brundall. The two trains involved were the 20:40 mail from Yarmouth Vauxhall and the 17:00 express from London to Yarmouth. The latter had left Norwich Thorpe at 21:30 and would normally have had a clear run on its way to Yarmouth, since the mail train should have been held on a loop line at Brundall to allow the express to pass. On this occasion trains were running late.

In such circumstances, when the timetable could not be kept, drivers had to have written authority to proceed further. Due to a series of errors (primarily, the telegraph clerk sending the authorisation message before it had been signed by the appropriate official), both drivers received their authority, and anxious to make up for lost time, set off at speed along the single track. The accident, when it occurred around 21:45, resulted in both locomotives rearing into the air, and carriages reduced to wreckage.

Both drivers and firemen were killed, as were seventeen passengers, with four later dying from their injuries.^[3] Seventy-three passengers and two railway guards were seriously injured.

Prompted by the accident, engineer Edward Tyer developed the tablet system in which a token is given to the train driver; this must be slotted into an electric interlocking device at the other end of the single-track section before another train is allowed to pass.^[3]