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THE SIGNAL BOX |
OVERSEAS |
New South Wales signalling closely follows British practice rather than American, apart from two lines which employ the CTC and Train Order systems. Although three-position upper quadrant signals were used for intermediate block signals in automatic sections in preference to multiple-aspect colour lights, they were not used for US-style speed signalling as they were in Victoria.
Track Circuit Block, or "Track Block" combined with intermediate automatic sections is the norm on the double lines in the electrified areas around Sydney and elsewhere, but in some non-electrified areas on the main South Line between Sydney and Melbourne the Block Telegraph system (Absolute Block) is still in use (2002) although its future is uncertain.
Most areas outside Sydney still employ mechanical signalling, although power systems are slowly spreading.
The city of Newcastle, around 100 miles north of Sydney, has three large mechanical boxes operating the area under Track Block using bells to signal trains. Newcastle box itself is "modern" in having electro-pneumatic point operation, worked from its miniature lever frame.
Most of the North Coast line is controlled through CTC (Centralised Traffic Control). Part of the Western Line is worked on the Train Order system, but most other single lines use the Electric Train Staff.
The NSW Rules for 1967 show a vast range of signal types, although many are probably obsolete now.
Distant signals in New South Wales are still painted red with a white chevron, and show a red or green light by night. However, a fixed green is provided above the arm for positive identification. All two-position signals are lower quadrant.
Three-position signals were certainly in use at one time, using the third aspect as both a distant signal in automatic sections, and for speed signalling at junctions.
Colour light signals are broadly similar in function to those in the UK, although the fourth aspect (equivalent of double yellow in the UK) is achieved by using a flashing yellow.
Multi-aspect, multi-light colour-light or Double Light Colour Light signals are used in the Sydney and Newcastle metropolitan areas, and most indications they give correspond to the standard colour-light route signalling system. The working of these is explained on a separate page.
One odd feature of signalling is found at the end of Track Block areas where approaching an interlocking. An "Accept" signal is provided, which is the first controlled signal a train would reach. Although the function of this signal may be thought of as similar to an Outer Home, at some locations there are both.
Compiled from notes by Adam Kinghi
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Comments about this article should be addressed to John Hinson |