Double line automatic signalling
Encyclopedia
Double Line Automatic Signalling is a form of railway signal
ling utilised on the majority of double line
sections in New Zealand
. Double Line Automatic Signalling utilises track circuit
s to detect the presence of trains in sections broken up by intermediate signals
.
Usually there is an 'up' and a 'down' main line, and beyond station limits the lines are not bi-directionally signalled.
At junctions or points, one of or both mains signals are usually controlled either remotely (by a Train Controller or Signalmen) or switched in at a local panel.
Sidings off one or both mains are usually operated by switchlock lever points secured by padlock and track circuit presence that enables a release to be given before points can be operated.
Railway signal
A signal is a mechanical or electrical device erected beside a railway line to pass information relating to the state of the line ahead to train/engine drivers. The driver interprets the signal's indication and acts accordingly...
ling utilised on the majority of double line
Double track
A double track railway usually involves running one track in each direction, compared to a single track railway where trains in both directions share the same track.- Overview :...
sections in New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. Double Line Automatic Signalling utilises track circuit
Track circuit
A track circuit is a simple electrical device used to detect the absence of a train on rail tracks, used to inform signallers and control relevant signals.- Principles and operation :...
s to detect the presence of trains in sections broken up by intermediate signals
Railway signal
A signal is a mechanical or electrical device erected beside a railway line to pass information relating to the state of the line ahead to train/engine drivers. The driver interprets the signal's indication and acts accordingly...
.
Usually there is an 'up' and a 'down' main line, and beyond station limits the lines are not bi-directionally signalled.
At junctions or points, one of or both mains signals are usually controlled either remotely (by a Train Controller or Signalmen) or switched in at a local panel.
Sidings off one or both mains are usually operated by switchlock lever points secured by padlock and track circuit presence that enables a release to be given before points can be operated.
Areas of use
- Swanson - New Lynn
- Avondale - Boston Rd
- Britomart - Westfield (via Penrose)
- Britomart - Amokura (via Waterfront)
- Te Kauwhata - Hamilton.
- Trentham - Kaiwharawhara
- Kaiwharawhara - South Junction
- North Junction - Paekakariki,
- Islington - Heathcote