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Introduction

The lines North and West of Inverness are controlled from two workstations in Inverness Signalling Centre. The RETB workstation was split into RETB West and RETB North from Sunday 2nd December 2018.

• The West workstation controls Inverness to Invergordon and Dingwall to Kyle of Lochalsh.
• The North workstation controls Invergordon to Wick and Georgemas Junction to Thurso.

• The Dingwall to Kyle line was the first to use Radio Electronic Token Block Signalling (RETB), being publicly launched on 6 July 1984 and becoming fully operational from 28 October 1984. The Far North Line from Dingwall to Wick and Thurso was converted to RETB in December 1985.
• These routes were initially controlled from Dingwall, and it was intended that the Inverness re-signalling scheme would include the Inverness - Dingwall section. However RETB was extended to Inverness with control moved to the new Inverness Signalling Centre in August 1988.

• The original radio System was altered in December 1992, with frequencies changed from VHF Band II to Band III.
• The 'Next Generation RETB' radio system was brought into full use from 4th December 2016, using radio channels in the 2XX series, with the 1XX numerical channel change boards removed, and Invergordon being the only location where manual radio channel change was required.
  • The main radio base stations for West section are: Mount Eagle (Channel 209), Garve (205), Achnasheen (210), Balnacra (203), Duncraig (208) and Kyle of Lochalsh (213).
  • The main radio base stations for North section are Fearn, Tain (216), Balblair Wood (212), Helmsdale (211), Knockarthur (213) and Ben Dorrey (210).

• Since April 2023, the two RETB workstations have been auto-reporting arrival and departure times of passenger trains to TRUST when token exchanges take place. For non-passenger trains, reporting to TRUST is still done manually, which may be some time after the event.

Route Signalling Description

This page describes the track layout and RETB signalling on these lines. Stations are shown in bold type.

RETB Signalling: Inverness - Invergordon

Controlled by Inverness Signalling Centre (RETB West workstation)

• Trains can enter the RETB system and obtain a token anywhere in the Inverness TCB area. Authority to proceed towards Clunes will be the clearing of the appropriate signal (I427 or I429) at the entry to the single line. Clachnaharry's Down signal 2 will only clear to green when an appropriate RETB token is issued.

Location	Mileage	Radio  Channel	Signalling	Remarks
Inverness Station	00mi 02ch	209	TCB (Inverness SC)	Terminus. Platforms 5, 6 and 7 for the North.
Rose Street Jn	00mi 19ch			Connection from 'Rose Street Curve', avoiding station.
	00mi 32ch		Down Signals I427, I429	Entry to the Single line
Ness Viaduct	00mi 41ch
	00mi 47ch		Up Signal I430	End of Radio Token Working (Up direction)
	01mi 12ch		Down Signal 2	Start of Radio Token Working (Down direction)
Clachnaharry Canal Bridge	01mi 45ch			Clachnaharry Bridge Box, controls Swing bridge and protecting signals
	01mi 68ch		Up Signal 1
(Delmore)	02mi 26ch			(Proposed Loop)
Bunchrew LC	03mi 58ch		ABCL
Clunes IB	07mi 51ch	209	TEP-i
Beauly	10mi 12ch			Single platform, Down side.
Muir of Ord	13mi 04ch	209	TEP (TPWS)	Two platforms. Right-hand crossing loop (466m/1530ft). Down Siding, trailing. Up Siding, facing.
Conon Bridge	16mi 21ch			Single platform, Up side.
Dingwall	18mi 58ch	209	TEP (TPWS)	Two platforms, left-hand crossing loop (410m/1345ft). Detaching Permitted. Down Siding, trailing.
Junction Points	18mi 76ch			Power Operated junction points. Setting: Down Plunger, Up track circuit
				Indications: B (Branch: Garve), M (Main: Invergordon)
Evanton IB	25mi 00ch	209	TEP-i (TPWS)
Alness	28mi 70ch			Single platform, Down side.
Invergordon	31mi 37ch	201	TEP (TPWS)	Two platforms, left-hand crossing loop (395m/1305ft). Up Siding, trailing.

• Invergordon is the change over location between RETB West and RETB North areas. On arrival drivers return the token, change radio channel, and follow the procedure for entering the new RETB area, before obtaining the next token.

RETB Signalling: Dingwall - Kyle of Lochalsh

Controlled by Inverness Signalling Centre (RETB West workstation)

Location	Mileage	Radio  Channel	Signalling	Remarks
Dingwall	00mi 00ch	209	TEP (TPWS)	Two platforms, left-hand crossing loop (410m/1345ft). Detaching Permitted. Down Siding, trailing.
Junction Points	00mi 19ch			Power Operated junction points. Setting: Down Plunger, Up track circuit.
				Indications: B (Branch: Kyle), M (Main: North Line)
Dingwall No.1 LC	00mi 57ch		AFBCL
Dingwall Middle LC	00mi 67ch		AFBCL
Dingwall No.2 LC	01mi 05ch		AOCL+B
Fodderty IB	02mi 31ch	205	TEP-i (TPWS)
Achterneed LC	04mi 55ch		AOCL+B
Garve	11mi 65ch	205	TEP (TPWS)	Two platforms, left-hand crossing loop (240m/800ft). Up Siding, facing.
Garve LC	11mi 72ch		ABCL	Driver's plunger on Garve Down platform, and plunger for Up direction Shunt.
Lochluichart	17mi 20ch			Single platform, Up side.
Achanult	21mi 37ch			Single platform, Up side.
Achansheen	27mi 72ch	210	TEP-i (TPWS)	Two platforms, left-hand crossing loop (305m/1010ft). Up Siding, trailing.
Achnashellach	40mi 34ch			Single platform, Down side.
Balnacra LC	42mi 12ch		AOCL+B
Blackwood No.2 LC	44mi 67ch		ABCL
Strathcarron	45mi 74ch	203	TEP (TPWS)	Two platforms, left-hand crossing loop (235m/780ft). Up Siding, trailing.
Strathcarron LC	45mi 75ch		AOCL+B	Driver's plungers on Strathcarron platforms, and plunger for Up direction Shunt.
Attadale	48mi 22ch			Single platform, Down side.
Stromeferry	53mi 15ch	208	TEP-i	Single platform, Up side.
Duncraig	57mi 09ch			Single platform, Down side.
Plockton	58mi 22ch			Single platform, Up side.
Duirinish LC	59mi 56ch		ABCL
Duirinish	59mi 58ch			Single platform, Down side.
Kyle of Lochalsh	63mi 64ch	213	TEP (TPWS)	Two Terminal platforms. Loop and Platform 2 access by Ground frames. Platform sharing permitted. East (Down) siding. West (Up) siding.

• Trains at Kyle normally arrive and depart from Platform 1 ('Up Platform' in the RETB system).
• Stromeferry TEP and permissive working at Kyle introduced from 24 April 2022.

RETB Signalling: Invergordon - Wick

Controlled by Inverness Signalling Centre (RETB North workstation)

• Invergordon is the change over location between RETB West and RETB North areas. On arrival drivers return the token, change radio channel, and follow the procedure for entering the new RETB area, before obtaining the next token.
• To the north of Invergordon there were originally five Intermediate Siding Ground Frames, all have now been plain-lined although they remain within the signalling data (Distillery No.1, Distillery No.2, BAC sidings, MK Shand No.1 and MK Shand No.2).

Location	Mileage	Radio  Channel	Signalling	Remarks
Invergordon	31mi 37ch	214	TEP (TPWS)	Two platforms, left-hand crossing loop (395m/1305ft). Up Siding, trailing.
Distillery No.1 GF	31mi 76ch		Sdg-i	Ground frame. Up Sidings, facing.
Distillery No.2 GF	32mi 07ch		Sdg-i	Ground frame. Down Sidings, trailing.
Delny LC	34mi 79ch		ABCL
Nigg LC	39mi 25ch			AHBC
Fearn	40mi 60ch	216	TEP-i	Single platform, Up side. Up Siding, trailing.
Tain	44mi 23ch	216	TEP (TPWS)	Two platforms, left-hand crossing loop (255m/840ft). Detaching Permitted. (Down Siding, trailing OOU).
Ardgay	57mi 70ch	212	TEP-i (TPWS)	Two platforms, left-hand crossing loop (435m/1430ft). Detaching Permitted. Down Siding, facing.
Culrain	61mi 00ch			Single platform, Down side. Request Stop Kiosk.
Invershin	61mi 34ch			Single platform, Down side. Request Stop Kiosk.
Lairg	66mi 78ch	206	TEP (TPWS)	Two platforms, left-hand crossing loop (302m/990ft). Up Sidings, trailing.
Lairg LC	67mi 07ch		AOCL+B	Driver's plunger on Lairg Down platform. (Also plungers for Shunting movements)
Acheilidh No.2 LC	72mi 63ch		ABCL
Rovie LC	76mi 35ch		AOCL+B
Rogart	77mi 01ch	213	TEP-i (TPWS)	Two platforms, left-hand crossing loop (330m/1095ft). Request Stop Kiosks.
Rogart LC	77mi 08ch			Open Level Crossing. (All Down trains must stop)
Kirkton LC	82mi 44ch		AOCL+B
Golspie	84mi 30ch			Single platform, Up side.
Dunrobin Castle	86mi 15ch			Single platform, Up side. Request Stop Kiosk.
Brora LC	90mi 31ch		AOCL+B	(Plunger for shunting movements)
Brora	90mi 48ch	211	TEP (TPWS)	Two platforms, left-hand crossing loop (370m/1220ft). (Up Siding, trailing OOU).
Dalchalm LC	91mi 30ch		AOCL+B
Helmsdale	101mi 40ch	211	TEP-i (TPWS)	Two platforms, left-hand crossing loop (255m/840ft). Down Siding, trailing.
Marrel LC	102mi 38ch		ABCL
Kildonan LC	111mi 03ch		ABCL
Kildonan	111mi 05ch			Single platform, Up side. Request Stop Kiosk.
Kinbrace	118mi 20ch			Single platform, Up side. Request Stop Kiosk.
Kinbrace LC	118mi 25ch		AOCL+B
Forsinard LC	125mi 67ch		AOCL+B	(Plunger for shunting movements)
Forsinard	125mi 69ch	204	TEP (TPWS)	Two platforms, left-hand crossing loop (250m/820ft). Up Siding, trailing.
Altnabrec GF	133mi 73ch		Sdg-i	Up Siding, trailing (for Engineer's trolleys only).
Altnabrec	133mi 76ch			Single Platform, Up side. (Proposed Request Stop Kiosk - TBC).
Scotscalder	143mi 02ch			Single Platform, Down side. Request Stop Kiosk.
Halkirk LC	145mi 59ch		ABCL
Halkirk IB	146mi 53ch	210	TEP-i	Down direction only. Combined with Distant board for Georgemas.
Georgemas Junction	147mi 20ch	210	TEP (TPWS)	Single platform (down side), Detaching permitted (Platform sharing possible) Up Loop (240m/800ft) ground frame controlled. Up Sidings, trailing.
				Power Operated junction points. Setting: Up plunger, Down track circuit.
				Indications: B (Branch: Thurso), M (Main: Forsinard)
Bower IB	147mi 56ch	210	TEP-i	Up direction only. Combined with Distant board for Georgemas.
Watten LC	153mi 68ch		AOCL+B
Wick	161mi 36ch	210	TEP (TPWS)	Single platform terminus. Platform sharing permitted. Loop controlled by ground frame. (Down Sidings OOU)

• The power operated points at Georgemas Junction were installed in February 1999. Prior to this the junction was operated with a ground frame.
• The Up Loop platform and footbridge at Georgemas Junction were removed by June 2012, and the 'Spent material loading facility' built around the Up through siding was commissioned in July 2012.
• Request Stop Kiosks were introduced at 7 stations in 2022-2023, following trials at Scotscalder.

RETB Signalling: Georgemas Junction - Thurso

Controlled by Inverness Signalling Centre (RETB North workstation)

Location	Mileage	Radio  Channel	Signalling	Remarks
Georgemas (Junction)	00mi 00ch	210	TEP (TPWS)	Power Operated junction points. Setting: Down plunger, Up track circuit.
				Indications: B (Branch: Thurso), M (Main: Forsinard)
Georgemas Branch	00mi 04ch	210	TEP-i	Branch Stop Boards within Georgemas Station Limits.
Hoy LC	00mi 72ch		AOCL+B
Thurso	06mi 50ch	210	TEP (TPWS)	Single platform terminus. Loop controlled by ground frame. Down Sidings, (Up 'Dock line' OOU).

Signalling Notes

• TCB: Track Circuit Block, controlled from Inverness Signalling Centre (I).
• TEP: RETB Token Exchange Point with stop boards
• TEP-i: Intermediate RETB Token Exchange Point. Trains with a 'Long Section' token may pass the stop board.
• Sdg-i: Intermediate Siding with shut-in facillity.
• TPWS: TEP equiped with Train Protection and Warning System. Blue light below Stop Board.
• GF: Ground Frame (controls points).
• Sidings: Out of Use and points removed.
• (OOU): Siding Out of Use, but still connected.
• IB: Intermediate Block Post
• LC: Level Crossing.
• AOCL: Automatic Open Level Crossing, locally monitored by train driver (flashing white signal).
• AOCL+B: Modified AOCL with addition of half barriers.
• ABCL: Automatic Half Barrier Level Crossing, locally monitored by train driver (flashing white signal).
• AHBC: Automatic Half Barrier Level Crossing, monitored at Signalling Centre.
• AFBCL: Automatic Full Barrier Level Crossing, locally monitored by train driver (flashing white signal).

External Links

• The Friends of the Far North Line
• FNL Request Stop Kiosks - Network Rail media release December 2022
• Comms Design - New Request Stop System on FNL