THE SIGNAL BOX
London, Midland & Scottish Railway
Location code: Sc62/02
Aberdeen South is essentially a large-scale variant of the design shown at Thornhill which was introduced in 1940 in reaction to the outbreak of the second world war. The sturdiness of construction and especially the thickness of the reinforced concrete roof is evident.
Aberdeen South opened in 1947 and was provided with an REC-type frame of
150 levers. In the process, two boxes were replaced, and this was probably on
the drawing boards before the end of the war, taking advantage of government
grants to carry out resignalling in the interests of having a defendable box
controlling such an important station. Retrospectively, the policy of using
valuable government funding to modernise signalling is distinctly
The Aberdeen area was latterly controlled from six boxes:
The original frame was renewed during the 1960s and the replacement was a Crewe-built BR(LMR) 4½" frame, the only example of this type to be installed in Scotland. The Scottish Region did not hold a high opinion of the REC type frame of the LMS and reverted to the use of Stevens'-style frames. This apparent regression was explained in 1985 by Jim Wallace, who had been the Regional Locking Inspector:
|I would agree that the LMS frame was a more modern design and
had a far greater mechanical advantage than the Stevens pattern design.
However, although the LMS frame was quite reliable locking-wise in a small
frame with the minimum of conditional locking, it was anything but reliable in
a bigger frame with a fair bit of conditional locking or even long runs of dead
locking, with a bit of use the locking got spongy and eventually failures
occurred. I think the classic case to illustrate what I am saying was when
Denburn Junction at Aberdeen, which was a 240 lever (Stevens) frame was
replaced by a new signal box . . . with a 150 lever (LMS) frame. The ground
layout did not alter much, the saving on levers was achieved by the fitting of
route indicators . . . one lever being used to cover a number of routes which
of course meant that a large amount of conditional locking was required. This
frame . . . was built at Crewe from standard material stored during the was for
ARP emergencies and was of the original type of BS (LMS) frame with the 1" wide
locks and ¼" x 5/16"
bridles. The frame however was not a great time in use when failures in the
form of "pull throughs" of the locking began to take place, accelerated in this
instance by a signalman who was a keen weightlifter and strength fanatic but a
very poor signalman. A great deal of time and money was used patching up this
locking but it was becoming a never-ending task and eventually it was decided
that the frame had to be replaced. A new frame was built at Crewe with heavier
locks and heavier bridles and, what was more important, a longer locking
travel; this was a one-off frame manufactured specially for
A further problem with the LMS frame for years was levers breaking just about quadrant level. The earlier levers were solid but later a separate corner was used but it was not until a modified shape of lever was used that the trouble subsided. A friction-type retarder was used for a spell to slow the signal levers returning to the normal position - the breakages were being caused by levers being allowed to return to return to normal uncontrolled - but these retarders were not popular as they also retarded the normal to reverse movement of the lever. I should add that replacing a broken lever was a bit of a trick especially when the lever was adjacent to the quadrant carrying the locking box bracket.
Thus the ScR's aversion to the frames that were imposed upon their established practices during World War II occurred. It is interesting to note that the LMS and BR (LMR) did not find such problems an issue (the frames had been in manufacture since around 1921) although unacceptable wear was identified in the 1970s and a few frames renewed in relatively small (but busy) boxes, such as Peak Forest South and London Road Junction, Leicester.
An impressive quantity of traditional signalling remained operational at Aberdeen until 1981, when the entire area was resignalled to be controlled from a new panel box nearby.
All photographs copyright © John Hinson unless otherwise stated