THE SIGNAL BOX

OVERSEAS

JOHANNESBURG
South African Railways

by John Hinson

Johannesburg signal cabin
Photograph from the collection of Dr. J W F Scrimgeour

This delightful period scene shows Johannesburg signal box, fast disappearing behind foliage. The ground-level box is located on the island "platform" for the station here did not have raised platforms.

The hipped-roof signal box, with the enamel "S" sign hanging up, portray a very "British" image but a step inside the box will reveal a truly different picture.

Interior of Johannesburg signal box
Photograph from the collection of Dr J W F Scrimgeour

Inside, we find a double-wire frame which indicates the Dutch connections - compare this with the view of Rietlanden Poste 1 in Holland. This is in fact a 1877-pattern Hollandsche Spoorwegmaatschappi (HSM) frame, and has the original vertical interlocking/catch handles, and is without locking camshafts at the rear. The interlocking was worked by hooks turning upwards from a range of eight axles in the bottom of the frame, driven by the cranks that can be seen attached to the front of the pulleys.

Signalling in Holland, in turn, based itself on German practice, so it isn't surprising to find that trains were signalled at Johannesburg on Siemens & Halske instruments - these are contained in the large metal box behind the left-hand end of the frame. The labels on these instruments read:

DOWN MAIN
UP MAIN
TO
DOORN JCN

FROM
BRAAM JCN
FROM
DOORN JCN
TO
BRAAM JCN

Operation of the plunger above the "from Braam Jcn" inscription would accept a train from that box, whilst operation of the "To Braam Jcn" would block the line behind a departing train. It is likely that these block instruments served purely as such and were not interlocked with the levers.

Interestingly, the Dutch translation for Braam is mulberry whilst Doorn translates to thorn. Braamfontein and Doornfontein are now east and west suburbs of Johannesburg.

The lever descriptions painted behind the levers will seem familiar to students of British signalling - those visible read:

2
UP MAIN
HOME
SIGNAL
3
UP MAIN
INTERMEDIATE
HOME
SIGNAL
4
UP MAIN
STARTING
SIGNAL
5
UP LOOP
TO
MAIN
INTERMEDIATE
HOME
SIGNAL
19.18


Signals at Johannesburg
Photograph from the collection of Dr. J W F Scrimgeour

On the approaches to the station in each direction, a pair of signals were provided in the configuration shown here. These too bear great similarities to HSM signals in Holland, only lacking the circular disc on the end of the arms. The striped posts, the quaint upper quadrant spectacles and the small diagonal slot bars above the spectacles to limit the movement are all typical of 19th century HSM signals, as is the balance rod half-way up the post - a primitive contraption required for double-wire operation.. The diamond symbol on the calling-on arms is not typical, however.

Nothing is known about the colouring or function of the signals, but it may be assumed that the lower pair read into the loops that bypassed the platforms.

Additional notes by Michiel Rademakers

About the photographs



Comments about this article should be addressed to John Hinson