230 THE BRIGHTON ROAD 
when no block system existed to render such close 
following comparatively safe. 
Clayton Tunnel was already considered a dangerous 
place, and there was situated at either end (north and 
south entrances) a signal-cabin furnished with tele- 
graphic instruments and signal apparatus, by which 
the Signalman at one end of the tunnel could com- 
municate with his fellow at the other, and could 
notify " train in " or " train out " as might happen. 
This practically formed a primitive sort of " block 
system," especially devised for use in this mile and a 
quarter's dark burrow. 
A "self-acting" signal placed in the cutting some 
distance from the southern entrance was supposed, 
upon the passage of every train, to set itself at 
' danger " for any following, until placed at " line 
clear ' from the nearest cabin, but on this occasion 
the first train passed in, and the self-acting signal 
failed to act. 
The second train, following upon the heels of the 
first, passed all unsuspecting, and dashed from daylight 
into the tunnel's mouth, the Signalman, who had not 
received a message from the other end of the tunnel 
being clear, frantically waving his red flag to stop it. 
This signal apparently unnoticed by the driver, the 
train passed in. 
At this moment the third train came into view, and 
at the same time the Signalman was advised of the 
tunnel being clear of the first. Meanwhile, the driver 
of the second train, who had noticed the red flag, was, 
unknown to the Signalman, backing his train out again. 
A message was sent to the north cabin for it, " train 
in "; but the man there, thinking this to be a mere 
repetition of the first, replied, " train out," referring, 
of course, to the first train. 
The tunnel being to the southern Signalman apparent- 
ly clear, the third train was allowed to proceed, and 
met, midway, away from daylight, the retreating second 
train. The collision was terrible; the two rearward 
carriages of the second train were smashed to pieces, 
