THE SIGNAL BOX

OVERSEAS

RENIGUNTA JUNCTION
Madras and Southern Mahratta Railway

by John Hinson

Renigunta West signal cabin
Photograph by Dr. J W F Scrimgeour 10/46

Situated at the west end of Renigunta Junction station in 1946 was this interesting cabin. It has no windows, and no walls below floor level - just a a paling palisade. However, in British terms, it isn't a signal box at all but just a "ground frame", manned as required and supervised from the station.

This view looks west along the broad (5'6") gauge single line towards Guntakel and Bombay, with the Eastern Ghats forming a backdrop. The overbridge in the distance carries the metre gauge line from Gudur, which swings round to call at the opposite face of the one platform at this station. The station is only a "junction" in respect of interchange.

Interior of cabin at west end of Renigunta Junction
Photograph by Dr. J W F Scrimgeour 10/46

The frame inside the cabin is of the same type as illustrated at Ghorpuri "B", though to be of local manufacture. The open element of the box design, together with the absence of permanent staff, have allowed the lever frame to weather noticeably.

Notice that one lever is provided with an Annett's key - they key probably releases a remote ground frame and can only be withdrawn from the frame when the lever is reversed. In turn, the reversal of that lever will ensure, through the interlocking, that the signals protecting that ground frame cannot be cleared.

Looking towards Renigunta staion
Photograph by Dr. J W F Scrimgeour 10/46

At the opposite end of the station is a similar cabin, and entry to the station from each direction is governed by a splendid three-doll bracket signal acting as the Inner signal. There are three lines through the station, but only the main (straight) route is served by the platform.

Under Indian signalling principles, the Inner signal is equivalent to the British Home signal, whilst the Outer is located some distance out, like a Distant signal, although the function is not quite the same. It is interesting to note the ground signal at the foot of the post is actually "upper quadrant" and similar to those installed by the London & North Eastern Railway.

The metre gauge line serving the other face of the platform curves quite sharply away to continue to Pakala Junction, whilst the M&SM line continues (behind the cameraman) on its journey to Madras.

Inside the Station Master's Office
Photograph by Dr. J W F Scrimgeour 10/46

Stepping inside the Station Master's Office on the platform, we find a pair of single-line instruments. In the centre of the picture is a metal-cased Neale's Ball Token instrument applicable to the nine mile section to Mamanduru on the broad gauge line towards Raichur, and a Theobald's Token (on the right) controls one of the metre gauge sections. The function of the device in the background is unknown; it may not be signalling related.

The station master also has his own mechanical frame outside the office on the platform. This controls all the running signals worked by the satellite cabins at each end of the station.

The metre gauge line through Renigunta Junction does have signalling but is interlocked by the Sequential Key Interlocking system. Like the broad gauge line, there is a platform face against the main line, and also a loop alongside.

An example of operation of the Sequential Key Interlocking System is as follows:

To receive a train on the platform line from Gudur

To receive a train on the loop line from Gudur

Key A was for the Gudur - Pakali Junction direction, and Key B for the opposite direction. Only one of these two keys could be released at once.

This method of working was very common on quieter branch lines in India, saving the cost of point rodding.

Around 1955, the metre gauge line to Gudur was converted to broad gauge, allowing a proper junction to be built at Renigunta.

About the photographs



Comments about this article should be addressed to John Hinson