Reversible Signalling - Revision history

Danny at 02:46, 1 February 2017

2017-02-01T02:46:56Z

← Older revision		Revision as of 02:46, 1 February 2017
Line 13:		Line 13:
	SIMplified BI-Directional (SIMBIDS) is a poorer-man's 'reversible'. It has no AWS magnets for the signals and the permanent AWS magnets for the normal direction signals are not suppressed, so trains receive lots of unnecessary horns ("Special AWS working"). It can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain.		SIMplified BI-Directional (SIMBIDS) is a poorer-man's 'reversible'. It has no AWS magnets for the signals and the permanent AWS magnets for the normal direction signals are not suppressed, so trains receive lots of unnecessary horns ("Special AWS working"). It can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain.

	Reversible used to have the same usage restrictions as ~~reversible~~, until Spring 2015 when it became allowed to use it for regulating purposes as well. The only remaining restriction on 'reversible' stopping it merging completely with 'bi-directional' is that two trains can't pass on reversible in opposite directions (ie, both on the wrong line).		Reversible used to have the same usage restrictions as SIMBIDS, until Spring 2015 when it became allowed to use it for regulating purposes as well. The only remaining restriction on 'reversible' stopping it merging completely with 'bi-directional' is that two trains can't pass on reversible in opposite directions (ie, both on the wrong line).

	Bi-directional can be used in either direction whenever required for any purpose.		Bi-directional can be used in either direction whenever required for any purpose.

Danny at 13:03, 22 November 2015

2015-11-22T13:03:31Z

← Older revision		Revision as of 13:03, 22 November 2015
Line 9:		Line 9:
	* SIMBIDS (a subset of reversible)		* SIMBIDS (a subset of reversible)

	All apart from the first are lines where trains can be signalled in both directions. The only* difference between them is procedural: Reversible (including SIMBIDS) lines can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain. Bi-directional can be used in either direction whenever required for any purpose.		All apart from the first are lines where trains can be signalled in both directions.

	~~To break~~ a ~~common misconception~~, the ~~difference~~ is ~~NOT~~ to ~~do with there being a 'normal' direction~~. ~~There are many bi-directional lines with a~~ '~~normal' direction and without~~.		SIMplified BI-Directional (SIMBIDS) is a poorer-man's 'reversible'. It has no AWS magnets for the signals and the permanent AWS magnets for the normal direction signals are not suppressed, so trains receive lots of unnecessary horns ("Special AWS working"). It can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain.

	~~SIMplified BI~~-~~Directional (SIMBIDS)~~ is ~~a poorer-man's~~ 'reversible', it can ~~only~~ be used in the ~~same circumstances* as~~ reversible~~, but it has no AWS magnets for the signals~~ and ~~the AWS magnets for the~~ normal direction ~~signals are not suppressed, so trains receive lots of unnecessary horns ("Special AWS working")~~.		Reversible used to have the same usage restrictions as reversible, until Spring 2015 when it became allowed to use it for regulating purposes as well. The only remaining restriction on 'reversible' stopping it merging completely with 'bi-directional' is that two trains can't pass on reversible in opposite directions (ie, both on the wrong line).

			Bi-directional can be used in either direction whenever required for any purpose.

			To break a common misconception, the difference is NOT to do with there being a 'normal' direction. There are many reversible and bi-directional lines with a 'normal' direction and without.

	Almost all the Main and Badminton Lines on Swindon Panel are reversible.		Almost all the Main and Badminton Lines on Swindon Panel are reversible.
Line 19:		Line 23:
	Reversible exists in the following sections: Milton - Wantage Road/[[Challow]] - [[Uffington]] - [[Bourton]] - [[South Marston]]* - Swindon East* - Swindon West* - [[Wootton Bassett]] (Main) - [[Thingley]] Junction - Bathampton Junction - Bath West - North Somerset, also Swindon West* to [[Wootton Bassett]] West - [[Hullavington]] - [[Chipping Sodbury]].		Reversible exists in the following sections: Milton - Wantage Road/[[Challow]] - [[Uffington]] - [[Bourton]] - [[South Marston]]* - Swindon East* - Swindon West* - [[Wootton Bassett]] (Main) - [[Thingley]] Junction - Bathampton Junction - Bath West - North Somerset, also Swindon West* to [[Wootton Bassett]] West - [[Hullavington]] - [[Chipping Sodbury]].

	There is also reversible between Teighmouth and Dawlish Warren, ~~however,~~ this ~~has been~~ approved for use for regulating, so is really 'bi-directional' now, according to the long-standing definition. This, and several other lines, are locally referred to as 'reversible' when they are really bi-directional (such at Exeter SD to Central and Yate to Westerleigh).		There is also reversible between Teighmouth and Dawlish Warren, and this was approved for use for regulating long before the rest of the WR reversible was. Only the up line is fitted, so as trains can't be signalled to pass each other in opposite directions, it is really 'bi-directional' now, according to the long-standing definition. This, and several other lines, are locally referred to as 'reversible' when they are really bi-directional (such at Exeter SD to Central and Yate to Westerleigh).

	West of Thingley Junction there is SIMBIDS onto the Bristol Panel area.		West of Thingley Junction there is SIMBIDS onto the Bristol Panel area.
Line 25:		Line 29:
	The lines through the platforms at Swindon are bi-directional. There is also a short section of bi-directional on the Down Main between [[Thingley]] Crossovers and Thingley Junction.		The lines through the platforms at Swindon are bi-directional. There is also a short section of bi-directional on the Down Main between [[Thingley]] Crossovers and Thingley Junction.

	The [[Gloucester Line]] is not anything, except for the single line part which is, of course, bi-directional.		The [[Gloucester Line]] is not anything, except for the single line part which was, of course, bi-directional.

	There ~~has been~~ one or two relaxations to the reversible limitations over the years, for example, a down ~~train~~ terminating at Swindon is permitted to ~~use~~ platform 4 and start back towards London via the Down Main Reversible to Bourton, but there are some limitations on ~~even~~ that.		There were one or two relaxations to the reversible limitations over the years before it became generally allowed to be used for regulating. For example, down trains terminating at Swindon was permitted to arrive in platform 4 and start back towards London via the Down Main Reversible to Bourton from about 2007, and down trains for Swindon Yard were allowed to cross to the Up Main at South Marston and enter the yard at the Highworth end from about 2010, but there are some limitations on that. These restrictions have been nullified now by the general allowance of reversible working whenever required.

	The locations with stars, above, have limited flexibility to cross trains over.		The locations with stars, above, have limited flexibility to cross trains over.
Line 34:		Line 38:
	Swindon East only has a facing crossover.		Swindon East only has a facing crossover.
	Swindon West only has a trailing crossover.		Swindon West only has a trailing crossover.

	* - Updated Spring 2015 - reversible (but not SIMBIDS) can now be used for traffic purposes. The only remaining restriction on 'reversible' stopping it merging completely with 'bi-directional' is that two trains can't pass on reversible in opposite directions (ie, both on the wrong line).

Danny at 12:57, 22 November 2015

2015-11-22T12:57:22Z

← Older revision		Revision as of 12:57, 22 November 2015
Line 9:		Line 9:
	* SIMBIDS (a subset of reversible)		* SIMBIDS (a subset of reversible)

	All apart from the first are lines where trains can be signalled in both directions. The only difference between them is procedural: Reversible (including SIMBIDS) lines can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain. Bi-directional can be used in either direction whenever required for any purpose.		All apart from the first are lines where trains can be signalled in both directions. The only* difference between them is procedural: Reversible (including SIMBIDS) lines can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain. Bi-directional can be used in either direction whenever required for any purpose.

	To break a common misconception, the difference is NOT to do with there being a 'normal' direction. There are many bi-directional lines with a 'normal' direction and without.		To break a common misconception, the difference is NOT to do with there being a 'normal' direction. There are many bi-directional lines with a 'normal' direction and without.

	SIMplified BI-Directional (SIMBIDS) is a poorer-man's 'reversible', it can only be used in the same circumstances as reversible, but it has no AWS magnets for the signals and the AWS magnets for the normal direction signals are not suppressed, so trains receive lots of unnecessary horns ("Special AWS working").		SIMplified BI-Directional (SIMBIDS) is a poorer-man's 'reversible', it can only be used in the same circumstances* as reversible, but it has no AWS magnets for the signals and the AWS magnets for the normal direction signals are not suppressed, so trains receive lots of unnecessary horns ("Special AWS working").

	Almost all the Main and Badminton Lines on Swindon Panel are reversible.		Almost all the Main and Badminton Lines on Swindon Panel are reversible.
Line 34:		Line 34:
	Swindon East only has a facing crossover.		Swindon East only has a facing crossover.
	Swindon West only has a trailing crossover.		Swindon West only has a trailing crossover.

			* - Updated Spring 2015 - reversible (but not SIMBIDS) can now be used for traffic purposes. The only remaining restriction on 'reversible' stopping it merging completely with 'bi-directional' is that two trains can't pass on reversible in opposite directions (ie, both on the wrong line).

Danny at 01:20, 30 December 2014

2014-12-30T01:20:43Z

← Older revision		Revision as of 01:20, 30 December 2014
Line 15:		Line 15:
	SIMplified BI-Directional (SIMBIDS) is a poorer-man's 'reversible', it can only be used in the same circumstances as reversible, but it has no AWS magnets for the signals and the AWS magnets for the normal direction signals are not suppressed, so trains receive lots of unnecessary horns ("Special AWS working").		SIMplified BI-Directional (SIMBIDS) is a poorer-man's 'reversible', it can only be used in the same circumstances as reversible, but it has no AWS magnets for the signals and the AWS magnets for the normal direction signals are not suppressed, so trains receive lots of unnecessary horns ("Special AWS working").

	Almost all the Main and Badminton Lines on Swindon Panel are reversible. ~~It can be worked~~ in the following sections: Wantage Road/[[Challow]] - [[Uffington]] - [[Bourton]] - [[South Marston]]* - Swindon East* - Swindon West* - [[Wootton Bassett]] (Main) - [[Thingley]] Junction - Bathampton Junction, also Swindon West* to [[Wootton Bassett]] West - [[Hullavington]] - [[Chipping Sodbury]].		Almost all the Main and Badminton Lines on Swindon Panel are reversible.

			Reversible exists in the following sections: Milton - Wantage Road/[[Challow]] - [[Uffington]] - [[Bourton]] - [[South Marston]]* - Swindon East* - Swindon West* - [[Wootton Bassett]] (Main) - [[Thingley]] Junction - Bathampton Junction - Bath West - North Somerset, also Swindon West* to [[Wootton Bassett]] West - [[Hullavington]] - [[Chipping Sodbury]].

			There is also reversible between Teighmouth and Dawlish Warren, however, this has been approved for use for regulating, so is really 'bi-directional' now, according to the long-standing definition. This, and several other lines, are locally referred to as 'reversible' when they are really bi-directional (such at Exeter SD to Central and Yate to Westerleigh).

	West of Thingley Junction there is SIMBIDS onto the Bristol Panel area.		West of Thingley Junction there is SIMBIDS onto the Bristol Panel area.

Danny: Bathampton added

2014-10-26T15:22:49Z

Bathampton added

← Older revision		Revision as of 15:22, 26 October 2014
Line 15:		Line 15:
	SIMplified BI-Directional (SIMBIDS) is a poorer-man's 'reversible', it can only be used in the same circumstances as reversible, but it has no AWS magnets for the signals and the AWS magnets for the normal direction signals are not suppressed, so trains receive lots of unnecessary horns ("Special AWS working").		SIMplified BI-Directional (SIMBIDS) is a poorer-man's 'reversible', it can only be used in the same circumstances as reversible, but it has no AWS magnets for the signals and the AWS magnets for the normal direction signals are not suppressed, so trains receive lots of unnecessary horns ("Special AWS working").

	Almost all the Main and Badminton Lines on Swindon Panel are reversible. It can be worked in the following sections: Wantage Road/[[Challow]] - [[Uffington]] - [[Bourton]] - [[South Marston]]* - Swindon East* - Swindon West* - [[Wootton Bassett]] (Main) - [[Thingley]] Junction, also Swindon West* to [[Wootton Bassett]] West - [[Hullavington]] - [[Chipping Sodbury]].		Almost all the Main and Badminton Lines on Swindon Panel are reversible. It can be worked in the following sections: Wantage Road/[[Challow]] - [[Uffington]] - [[Bourton]] - [[South Marston]]* - Swindon East* - Swindon West* - [[Wootton Bassett]] (Main) - [[Thingley]] Junction - Bathampton Junction, also Swindon West* to [[Wootton Bassett]] West - [[Hullavington]] - [[Chipping Sodbury]].

	West of Thingley Junction there is SIMBIDS onto the Bristol Panel area.		West of Thingley Junction there is SIMBIDS onto the Bristol Panel area.

Danny: Note added to say this is WR

2014-09-26T14:23:12Z

Note added to say this is WR

← Older revision		Revision as of 14:23, 26 September 2014
Line 1:		Line 1:
			As with a lot of nomenclature, there is a lot of regional variation in naming, application, useage, etc. The following description relates to Western Region thinking:


	There are four ways of classifying running lines in terms of their direction:		There are four ways of classifying running lines in terms of their direction:

Danny at 22:14, 10 August 2014

2014-08-10T22:14:51Z

← Older revision		Revision as of 22:14, 10 August 2014
Line 6:		Line 6:
	* SIMBIDS (a subset of reversible)		* SIMBIDS (a subset of reversible)

	All apart from the first are lines where trains can be signalled in both directions. The only difference between them is procedural: Reversible (including ~~SIMBIDs~~) lines can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain. Bi-directional can be used in either direction whenever required for any purpose.		All apart from the first are lines where trains can be signalled in both directions. The only difference between them is procedural: Reversible (including SIMBIDS) lines can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain. Bi-directional can be used in either direction whenever required for any purpose.

	To break a common misconception, the difference is NOT to do with there being a 'normal' direction. There are many bi-directional lines with a 'normal' direction and without.		To break a common misconception, the difference is NOT to do with there being a 'normal' direction. There are many bi-directional lines with a 'normal' direction and without.

Danny at 10:41, 20 July 2014

2014-07-20T10:41:12Z

← Older revision		Revision as of 10:41, 20 July 2014
Line 4:		Line 4:
	* Bi-directional		* Bi-directional
	* Reversible		* Reversible
	* ~~SIMBIDs~~ (a subset of reversible)		* SIMBIDS (a subset of reversible)

	All apart from the first are lines where trains can be signalled in both directions. The only difference between them is procedural: Reversible (including SIMBIDs) lines can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain. Bi-directional can be used in either direction whenever required for any purpose.		All apart from the first are lines where trains can be signalled in both directions. The only difference between them is procedural: Reversible (including SIMBIDs) lines can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain. Bi-directional can be used in either direction whenever required for any purpose.

Danny at 18:54, 18 July 2014

2014-07-18T18:54:02Z

← Older revision		Revision as of 18:54, 18 July 2014
Line 1:		Line 1:
	There are ~~three~~ ways of classifying running lines in terms of their direction:		There are four ways of classifying running lines in terms of their direction:

	* One-directional		* One-directional

Danny at 14:44, 18 July 2014

2014-07-18T14:44:34Z

← Older revision		Revision as of 14:44, 18 July 2014
Line 4:		Line 4:
	* Bi-directional		* Bi-directional
	* Reversible		* Reversible
	* SIMBIDs (a subset of ~~SIMBIDs~~)		* SIMBIDs (a subset of reversible)

	All apart from the first are lines where trains can be signalled in both directions. The only difference between them is procedural: Reversible (including SIMBIDs) lines can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain. Bi-directional can be used in either direction whenever required for any purpose.		All apart from the first are lines where trains can be signalled in both directions. The only difference between them is procedural: Reversible (including SIMBIDs) lines can only be used when the correct line is not available, due to engineering work, infrastructure failure, train failure, etc. It can't be used for commercial/performance gain. Bi-directional can be used in either direction whenever required for any purpose.