THE SIGNAL BOX

OVERSEAS

HORNSBY
New South Wales Government Railways

by John Hinson

Hornsby signal cabin
Photograph 1909, from the collection of Dr J W F Scrimgeour

Although the New South Wales Government Railways adopted simple and economical signalling at their remoter stations (see Blayney), main lines and important stations were provided with comprehensive signalling and signal boxes of more typical construction.

The original facilities at Hornsby were distinctly basic, comprising a tall single-post two-arm semaphore and hand-operated points. In the 1890s, facilities were improved by the provision of an open frame on the platform with the block and staff instruments housed in an adjacent shed.

However, in 1909 a large signal box had to be provided to work a hugely enlarged layout. The station, which was 21 miles from Sydney on the Main Northern line to Newcastle, became the outer terminus of the suburban services from Sydney, both via the Main Northern route and via the newly doubled North Shore line. The main line was also doubled towards Newcastle, and the resulting arrangements necessitated the provision of a signal box of over 100 levers.

Interior of Hornsby box
Photograph c1928, from the collection of Dr J W F Scrimgeour

A night-time view inside the box reveals a large quantity of staff in evidence, ranging from boiler-suited signal workmen to hatted inspectors. It may be that the grand occasion is the de-commissioning of the box, for it was superseded as early as 1928. This photograph was used for a caption competition in the monthly quiz on this we site in September 2002.

The frame, like the box, is of standard McKenzie & Holland design. McK&H were English signalling contractors, but they set up a works in Australia and thus secured almost all signalling work both there and in New Zealand. Only the NSWGR produced their own frames, but as evidenced here, this was not exclusive.

One sole block instrument is visible on the block shelf, and this is a Tyer's one-wire, three-position instrument. Two more blocks would also be necessary - no doubt these are out of view to the left.

The two signal box diagrams do not duplicate each other, as is the most common practice, but divided to show the layout at each end of the station, although there is a measure of overlap.

This mechanical cabin was replaced in the late 1920's with a power installation using the NSWGR type H pistol-grip frame (as Illustrated at Sydney Station West) and although replaced by modern Solid State Interlocking some years ago that structure still stands in 2006.

Noel Reed wrote on the later box, in 2007:

The 1928 Hornsby signal box with it's 120 lever Type H pistol grip interlocking machine has been out of service for about seven years since being replaced by the Hornsby signalling control centre with Solid State Interlocking.

Work has been going on now for many months for the provision of an additional platform (No. 5), the track for which will pass on the Down (west) side of the old buildings on Platform 4.
The Hornsby signalling control centre will have a Westlock computer based interlocking for the new work.

It was earlier thought that the new fifth track would pass through the space between the rear of the old signal box and the former 1500v DC traction substation.

It is now evident that this will not be the case and it is proposed to move the old signal box in a southward then westward direction from it's present position so that the rear of the signal box will be close the Down side railway boundary adjoining Jersey Street.

This work is under the control of the Transport Infrastructure Development Corporation (TIDC).

Moving the signal box should be an interesting project as it is of brick construction for the relay room and former signal electricians' depot while the operating floor is of cladded timber construction with a slate roof.

I observed today (25/05/07) from a passing train that an excavation has been commenced by contractors at the southern end of the old signal box so that supporting beams can be placed beneath the building ready for the move. It appears that an AC power transmission line pole would have to be relocated before the signal box can be moved.

On inquiring from the Hornsby Station Manager (Master), I was told that the move was to take place in about eight weeks time. It may be worthwhile for those interested to make a photographic record of this work. A view of the signal box can be obtained from the northern end of the railway station car parking area during mornings when illumination is the best.. A closer view of the excavation could only be obtained from within the railway area, possibly from a passing train.


Now a 4 September 2007 update of the above story ---

Last week the Hornsby signal box was raised by approximately two metres. I saw it today and it is now supported by a number of Rolled Steel Joists (RSJ) placed front to rear beneath the concrete foundation . These RSJs are in turn supported by two massive RSJs placed end to end beneath the signal box. These large RSJs are in turn supported by a number of timber 'pigsties' which have been placed in position after the large RSJs have been gradually raised by hydraulic jacks.

About mid day today, I observed a small 'bobcat' moving and levelling the earth beneath the raised signal box. Timbers have now been placed on the earth beneath the entire building.

A total of twelve (12) large 'bogies' with dual rubber tyres (a total of 12x8 = 96 wheels) are ready nearby so as to be placed beneath the large RSJs to move the signal box some 50 - 60 metres in a southward direction towards Hornsby station. It appears that the move will be in one direction only to allow clearance from the down side of the new fifth track which will pass through the station on the west side of the original station buildings on No 4 platform

The new fifth track at Hornsby station will pass in front of the relocated signal box and not through the space between the signal box and the former traction sub station. The fifth track will in fact pass through the position originally occupied by the signal box i.e where it stands raised today.

I have been informed that the move of the signal box is proposed to be on Monday, 10 September 2007.

 

Additional notes by Noel Reed


Comments about this article should be addressed to John Hinson