The largest mechanical signal box in Australia

by John Hinson

A general view of the terminal station with Spencer Street box on the leftThe terminal part of Spencer Street station in Melbourne survives by dint of ownership as an oasis of mechanical signalling amidst the modernised railway signalled from the Metrol Control Room.

Spencer Street No1 box controls the station and throat area, and whilst the signalling is all colour-light, the layout is almost entirely controlled from a mechanical frame.

A view down the length of the 192-lever frame in Spencer Street No1.And just look at the length of the frame! Doesn't the signalman at the far end look small? There are no less than 192 levers here, although amongst them there are a handful of spare and removed levers. There is no bigger box in Australia, nor probably in the world.

The frame itself is in three sections, owing to several enlargements having been made to the box. The frames are of the ubiquitous McKenzie & Holland design with 5" centres, provided with Cam & Soldier (1873-style) locking.

Another view inside Spencer Street No1The box is manned by two signalmen at a time, although the work they share includes the record-keeping and radio and telephone work at the back.

One of the signalmen stands here in front of one of a number of small auxiliary panels to work areas of control added to the box layout.

Levers 191 and 1 are next to each other!The history of the box is complex, and when the first significant extension to the box was made to accommodate more levers, this was done at the right-hand end to allow an additional 43 levers to ba added to the original 120.

But later, more levers were called for, and a further 29 levers were added at the left-hand end. The British principles that would require levers added at the left end to carry letters A, B, C etc. rather than numbers (or the entire frame renumbered) was applied at some locations in Victoria but in this instance this last extension was simply numbered 163 to 192.

In fact, lever 192 has become redundant at some stage and has been removed, so the highest visible number is 191 - in this view the levers up to 191 can be seen alongside those numbered from 1 upwards. If this view is not clear enough to show this, please click on the image for an enlargement of the badges.

Part of the signalling diagram at Spencer Street No1 boxThe signalling plan for Spencer Street No1 box is much like a British illuminated diagram, with pairs of red lamps indicating occupied track circuits.

Please click on the image if you would like to see an enlargement of this view.

The rest of the layout!And here is the other half! Again, you can see an enlarged view by clicking on the image.

Panel controlling Moonee Ponds Creek JunctionThis is one of the small additional panels controlling extra parts of the layout. This one controls Moonee Ponds Creek Junction (how delightful that sounds) and shows the standard gauge route as it approaches Spencer Street. This links up on the main diagram as the line shown in blue - first at the bottom right corner and then continuing in top right.

Although the diagram shows several connections running into the single line, they were no longer controlled from Spencer Street by the time of this visit. This is because the line has been handed over to ARTC (Australian Rail track Corp) and the area is now remotely controlled from Adelaide. Just one controlled signal remains, worked by the one switch in the two rows that still has a knob on it - bottom left.

Dual gauge pointwork at MelbourneAlthough the permanent way isn't my real area of interest, this piece of track is worth of special mention.

At this point, dual gauge track diverges and the different gauges go their separate ways. This is achieved without any moving point blades etc. Trains of the different gauges are routed purely by the provision of check rails in the appropriate places. You may find you need to study the picture closely to fully fathom out how this works.

If you've still time to waste (!), see if you can work out from the diagram above where these points are in the layout plan.

The signalling here follows the Speed Signalling principles, so route indicators are not normally needed. However, one is provided at the signal for these points, just to ensure that the correct gauge train is signalled for the correct route!

As of 2005, the layout here has changed - Platform 1 has been removed and a new platform created next to Platform 2, making an island platform. The only standard gauge facilities here now are for one 8-car XPT train (the equivalent of the British HST). Some storage sidings have also been abolished since my visit.

Shunting crew at restThe overworked (!) shunting crew take a break between shunts in the station sidings.

Shunting at Spencer StreetBut it isn't all rest. Here they are manoeuvreing an afternoon outer suburban departure into the appropriate platform. The signalman would have had a fair few levers to pull to set up the ladder crossing towards the carriage sidings.

The box itself was originally to the same design as Bacchus Marsh, but the enlargements and window renewals have left little in the way of original features.

Since writing this article, I have been told that Spencer Street No1 box was decommissioned at 23:16 hours on Friday 6th June 2008. The new No. 1 box is a temporary building near the former. Another gem passes into history!

Additional notes by Rom Ballard, Daniel Crawford and Noel Reed.

Comments about this article should be addressed to John Hinson