Norwegian railway signalling

The signalling system used on the rail transport in Norway is regulated by the Regulations of December 4, 2001 no. 1336 about signals and signs on the state's railway network and connected private tracks.

The first signalling system on the Norwegian railway system was a mechanically operated semaphore system introduced at Drammen station in 1893. The first electrically operated light signal system was delivered by AEG in 1924. Today, only electrically operated light signals are used.

Train radio

Between 1993 and 1996, NSB rolled out the analog train radio system Scanet. Developed by Ascom Radiocom, it was only installed on the primary railway lines. The system allows radio communication between a train dispatcher, and train drivers and other users involved in railway operations. Scanet was also connected to the automatic train control system.^[1] However, several lines lack the system, including the Arendal Line, the Flåm Line, the Meråker Line, the Nordland Line, the Rauma Line, the Røros Line, the Inner Østfold Line, the northern part of the Gjøvik Line, and several tunnels along the Bergen Line and the Sørland Line. The Åsta accident in 2000 spurred the need to give all parts of the railway coverage with train radio.^[2] On these lines, the dispatcher and drivers must communicate using the Nordic Mobile Telephone (NMT 450) standard, which by 2002 was being planned terminated by Telenor.^[3]

Scanet was replaced by Global System for Mobile Communication – Railway (GSM-R) between 2004 2007, with the systems first being installed on the lines without Scanet.^[4] The system, delivered by Nokia Siemens Networks, was on time and on budget, and made Norway one of the first countries to fully implement the system throughout Europe.^[5] After GSM-R was fully implemented on 1 November, Scanet was gradually closed.^[6] The new system has been characterized as simpler to use and giving better audio quality than Scanet.^[7] The implementation cost 1.8 billion Norwegian krone and covers the entire network.^[4]

Signalling remedies

The following signalling remedies are used:

• Signal flags
• Hand-held signal lamps
• Signal whistle
• The signal giver's arms
• Fixed light signals
• Fixed sound signals
• Signal signs
• Orientation poles
• Locomotive whistle
• Locomotive and train signal lamps

The fundamental meaning of the signal colors

• Red always indicates "stop".
• Violet indicates that the associated level crossing signal shows "Stop short of the level crossing".
• Yellow indicates "caution".
• Green indicates "permission to run".
• White indicates "clear line".

Light signals

The regular light signals show one of these signals:

Main signals

Signal		Meaning	Used in
	Signal 20A – Stop – flashes	The train must stop short of the signal.	Home signals, block signals.
	Signal 20B – Stop	The train must stop short of the signal.	Departure signals, inner signals.
	Signal 21 – Proceed (to diverging route)	The train can proceed, usually via one or more diverging switches.	Home signals, departure signals, inner signals, block signals.
	Signal 22 – Proceed	The train can proceed, not via diverging switches.	Home signals, departure signals, inner signals, block signals.

Fail safe

If one of the green lights in signal 22 fails, the indication becomes the lower speed signal 21 – this is fail-safe. Other nearby countries reverse the role of the single green aspect and double green aspect.

Distant signals

Image	Signal	Meaning
	Signal 23 – Expect stop – flashes	The associated main signal shows signal 20A or 20B.
	Signal 24 – Expect to proceed (to diverging route) – flashes	The associated main signal shows signal 21.
	Signal 25 – Expect to proceed – flashes	The associated main signal shows signal 22.

Wrong-side failure

If the yellow light in signal 24 fails, the signal displays a higher speed indication, which would be a wrong-side failure. To prevent this, the yellow light would be proved to be operating before the green light is displayed (that is, the yellow is shown before the green, if the yellow fails, the green isn't shown and the signal stays totally dark).

Warning systems

Norway uses the Ericsson ATP warning system, also used on Perth's suburban railway network.

References

1. ^ Solberg, Bjørn Olav (1994). "Train radio system for Norwegian State Railways". Telektronikk (Telenor) (4): 73–81. Archived from the original on 24 October 2010. http://www.webcitation.org/5tiypSO3C. Retrieved 24 October 2010. 
2. ^ Enghaug, Paul (11 February 2002). "NSBs nye togradio holder bare fem år" (in Norwegian). Aftenposten: p. 11. 
3. ^ Melsom, Jens (10 January 2002). "Kommentarer til høring– Fremtidig bruk at NMT-450 frekvensbåndene" (in Norwegian). Norwegian Post and Telecommunications Authority. Archived from the original on 24 October 2010. http://www.webcitation.org/5tiyhm0OP. Retrieved 24 October 2010. 
4. ^ ^{a b} "GSM-R tatt i bruk som togradio". Computer Weekly. 1 November 2007. http://www.jernbaneverket.no/no/Nyheter/Pressemeldinger/2007/GSM-R-tatt-i-bruk-som-togradio/. Retrieved 24 October 2010. 
5. ^ Savvas, Antony (19 November 2007). "Norwegian rail system migrates to mobile network to improve safety". Computer Weekly. Archived from the original on 24 October 2010. http://www.webcitation.org/5tj2CChtd. Retrieved 24 October 2010. 
6. ^ "Høring – Endring av togframføringsforskriften og signalforskriften bl.a. som følge av innføring av GSM-R som togradio mv." (in Norwegian). Norwegian Railway Inspectorate. 6 July 2007. Archived from the original on 24 October 2010. http://www.webcitation.org/5tj3LkR2V. Retrieved 24 October 2010. 
7. ^ Nørbeck, Fredrik (2008). "GSM-R". Lokomotivmands Tidende (National Union of Norwegian Locomotivemen) (3): 14. Archived from the original on 24 October 2010. http://www.webcitation.org/5tj3kaXXG. Retrieved 24 October 2010. 

External links

Norwegian signalling rulebook