Signaling Systems in Ireland

godtabh

I was reading a report on an accident in Canada that caused the death of a train diver and a trainee.

They went through (either not seeing a signal or ignoring it) and went through a switch at too fast a speed.

I know that IR have CTC but I think that is more for dart. What signaling system is in operation for intercity trains? And the luas?

How are these systems maintained to ensure that there is no failures? I assume they have to conform to some EU safety standards

highlydebased

godtabh wrote: »

I was reading a report on an accident in Canada that caused the death of a train diver and a trainee.

They went through (either not seeing a signal or ignoring it) and went through a switch at too fast a speed.

I know that IR have CTC but I think that is more for dart. What signaling system is in operation for intercity trains? And the luas?

How are these systems maintained to ensure that there is no failures? I assume they have to conform to some EU safety standards

A combination of CTC and mini-ctc almost all over Ireland. Semaphores still exist on Killonan Jctn-Ballybrophy and Clonmel-Waterford

Solair

I'm not sure exactly what the difference between CTC and Mini-CTC is.

I know the signalling on the DART, Cork-Dublin line and Dublin-Belfast line and probably Galway as far as Athlone is full CTC stuff.

Other lines were upgraded relatively recently, so I would assume the signalling is reasonably high tech.

There were certainly some ancient clapped-out signalling systems on some of the smaller lines until quite recently though. They're all gone now as far as I am aware.

I would also suspect that the main reason such old technology was surviving here is that the frequency of trains on lines other than the Cork-Dublin corridor and Dublin-Northeast (as well as busier commuter areas DART, etc) is really limited, so they didn't need all that much high tech gear to manage traffic i.e. one train every couple of hours in a lot of cases.

godtabh

I thought CAWS was in operation (found from googleing)

godtabh

Dont suppose there is a map of what systems are in operation on what lines?

cml387

Solair wrote: »

I'm not sure exactly what the difference between CTC and Mini-CTC is.

I know the signalling on the DART, Cork-Dublin line and Dublin-Belfast line and probably Galway as far as Athlone is full CTC stuff.

Other lines were upgraded relatively recently, so I would assume the signalling is reasonably high tech.

There were certainly some ancient clapped-out signalling systems on some of the smaller lines until quite recently though. They're all gone now as far as I am aware.

I would also suspect that the main reason such old technology was surviving here is that the frequency of trains on lines other than the Cork-Dublin corridor and Dublin-Northeast (as well as busier commuter areas DART, etc) is really limited, so they didn't need all that much high tech gear to manage traffic i.e. one train every couple of hours in a lot of cases.

AFAIK Limerick Junction - Waterford is train staff and semaphore.

The Luas seems still capable of a SPAD as we saw today,well the court case at least.

L1011

Luas is entirely under driver control, signalling system is indicative not controlling.

Losty Dublin

CTC isn't a signaling system, it's the name of the central signal box that controls the majority of the Irish network.

In very short terms, the three main systems of signaling are track circuit block, absolute block signaling and one train in steam.

• Track Circuit Block is a combination of remotely operated points and electrically colour light signaling. It relies on sensors on the track to detect a trains where about's and is controlled remotely from a few locations, mainly from Connolly CTC. There are a few smaller cabins which control specific lines using a simplified system; to most railway workers it's called Mini CTC which is a simplified system.
  In addition to this, trains are also fitted with a in cab signal reading system called Continuous Automatic Warning System (CAWS) which shows the color of the forthcoming signal ahead of the time. This works only on certain sections of lines so it's not applicable nationally.
• Absolute block signaling is the old system and is generally mechanically worked points and the old orange signals. It works on the principal of only allowing one train into a track section between signal boxes at any one time. The track sections are called blocks and when a train is in a block section, a permission is given to the driver by the local signal man that they have the signal mans blessing to be on that section of line; this is usually in the form of a staff or token that is withdrawn from a signal machine which releases that block sections signals and points. Modern
  Navan-Navan Mines, Ballybrophy-Limerick and Tipperary-Waterford are the only lines in the Republic using this system in daily use.
• One train in steam works on the basis that only train is on a line at any one time with that train holding permission to operate on a given line at a given time. The only passenger line using this system in Ireland is Colraine-Portrush in Antrim although it can revert to Block working during busy periods of traffic. A few of the closed to traffic lines use this system if and when they are used by traffic/

There is far more than this that could be added but it's a very simple starting point. Lines in the north have a similar set up to here as well.

Losty Dublin

godtabh wrote: »

Dont suppose there is a map of what systems are in operation on what lines?

Off the top of the head, CTC controls the following....

Dublin-Newry;
Dublin-Cork;
Dublin-Greystones;
Dublin-Waterford West;
Dublin-Maynooth;
Islandbridge-Glasnevin Junction;
Glasnevin Junction-Docklands;
Dublin-Limerick;
Dublin-Knockcroughery
Dublin-Ballinasloe.
Athlone-Moate

All of these lines use CAWS as well.

Heuston retains a signalbox for the yard and approach.

Aside from the closed/disused lines, all other sections are controlled with Mini CTC except the mechanical lines I mentioned above. I'll dig out the local Mini CTC boxes in a while.

The main difference is that there's no CAWS on Mini-CTC lines. Mini-CTC lines use axle counters rather than track circuits for train detection and these cannot carry the signals required for CAWS to work. Some parts of the Dublin-Cork mainline were rebuilt with axle counters but these were bridged to allow CAWS to keep working. The DART uses the ATP system.

Luas is entirely driver controlled. You may have noticed the "Check Your Route" signs at Luas junctions, this is because the points are set manually by the driver.

Our man in Havana

What do the letters on signal posts mean? CY, RL, WL etc?

Our man in Havana

Our man in Havana wrote: »

What do the letters on signal posts mean? CY, RL, WL etc?

I'm not 100% sure of this but I've been told that the letters represent the Emergency Control Panel (ECP) that will take control of the post should a problem occur at CTC in Dublin.

Hilly Bill

Our man in Havana wrote: »

What do the letters on signal posts mean? CY, RL, WL etc?

CY is Connolly Yard. Rl Rosslare? Where have you seen WL?

Bl is Belfast, Cl is Clonsilla.

kc56

Hilly Bill wrote: »

CY is Connolly Yard. Rl Rosslare? Where have you seen WL?

Bl is Belfast, Cl is Clonsilla.

HN= Heuston
HK= Heuston-Kildare

Before the upgrade to HK, Kildare route used to be CY - Conolly CTC or Cherryville?

kc56

kc56 wrote: »

Before the upgrade to HK, Kildare route used to be CY - Conolly CTC or Cherryville?

It was Connolly. The first section of CTC was from Heuston to Ballybrophy, controlled from Connolly.

WL I think is Waterford Line. I'm sure I've seen it myself.

Our man in Havana

WL is on the Waterford line south of Athy.

Hungerford

Losty Dublin wrote: »

There is far more than this that could be added but it's a very simple starting point. Lines in the north have a similar set up to here as well.

The set-up in the North is as follows. Most of the network is track circuit block with colour light signals controlled by a trio of central signal cabins.

Belfast Central controls Belfast-Larne, Belfast-Magherabeg (on the Derry line), Belfast-Lisburn and Belfast-Bangor. Portadown controls Lisburn-Border. Coleraine controls Magherabeg-Coleraine.

The North-West portion of the network remains reliant on mechanical signalling, involving an array of different signal types. The sections are: Coleraine-Castlerock, Castlerock-Derry and Coleraine-Portrush.

All are worked using variations of the token system. Portrush and Castlerock have semaphore signals to control their station surrounds while Coleraine and Derry have colour light signals. The City of Derry Airport's control tower also has a signal panel which can control the signals close to its runway if necessary.

Two sections are generally worked using one engine in steam. Coleraine-Portrush, where access is granted using a token obtained from Coleraine signal box while the mothballed Lisburn-Antrim branch is operated using a pilot man.

A Dub in Glasgo

The prefix to the signals is usally the controlling box or the interlocking or panel if it is centralised control

On the general point of the original post, the signalling system is fail safe which means if it fails the signal will revert to the most restrictive aspect. Sounds like the accident described in Canada was human error which of course is not fail safe. There are protection systems to mitigate human error such as CAWS and ATP for the DART. In the UK, the system tends to be AWS and TPWS with ETCS coming soon.

The issue here is the cost - the more you want to protect and mitigate, the more it will cost. The value of 'life saved' for business case decisions for investment in rail safety systems is much much higher than the value of 'life saved' for the road network. This is one of the major reasons railways cost so much and the comparison that a lot of people seem to do of 'My ticket to X is so expensive, it would be cheaper for me to drive' is not comparing like for like.

dowlingm

Cab signalling systems aren't common in North America and there is fierce resistance to their implementation because of cost and because in the US the freight RRs are already annoyed that they must allow passenger services and that this now means they have to implement Positive Train Control.

There were three people in the cab of VIA 92 (normal company ops is two) and the "trainee" was actually an experienced engineer from a freight RR transferring to VIA. TSB has not published a final report but VIA has no "Silent Witness" gear like Amtrak does of forward cameras or audio in the cab.

mk6705

Karsini wrote: »

The main difference is that there's no CAWS on Mini-CTC lines. Mini-CTC lines use axle counters rather than track circuits for train detection and these cannot carry the signals required for CAWS to work. Some parts of the Dublin-Cork mainline were rebuilt with axle counters but these were bridged to allow CAWS to keep working. The DART uses the ATP system.

Luas is entirely driver controlled. You may have noticed the "Check Your Route" signs at Luas junctions, this is because the points are set manually by the driver.

I would have thought mini-CTC lines used track circuits (Judging mainly from Mallow - Tralee here.) . In fact I'd be pretty sure of that. Any British trains I've been on made that loud, distinctive noise when going over axle counters, this is rarely heard in Ireland except at special locations. The reason they don't have CAWS is much more to do with cost I reckon. Correct me if I'm wrong of course.

A Dub in Glasgo

Most axle counters are electronic therefore there is no sound when the wheels go over them. I have never heard the sound you refer to above. Maybe you mean treadles which are used with level crossing systems although I am not so sure you can hear the treadle being pressed by the wheels?

kc56

Adro947 wrote: »

I would have thought mini-CTC lines used track circuits (Judging mainly from Mallow - Tralee here.) . In fact I'd be pretty sure of that. Any British trains I've been on made that loud, distinctive noise when going over axle counters, this is rarely heard in Ireland except at special locations. The reason they don't have CAWS is much more to do with cost I reckon. Correct me if I'm wrong of course.

Axle counters are magnetic sensors that sit beside the rails and detect the steel in the wheels as they pass over them. There are no sounds associated with axle counters, no clacks as the rail is not cut. Axle counter are fitted to the Dublin/Cork line between Inchicore and Cherryville. The 'distinctive noise, is much more likely to be track-circuit breaks as the rails have to be cut and insulated blocks inserted; they may be expansion joints.

On the KRP, while axle counters are used, insulated blocks are also installed at each signal; these are not for track circuits but are required for CAWS. CAWS delivers in-cab information continuously via signals transmitted in the rails. Having insulated joints at every signal negates one of great advantages of axle counters in that you can have very long unbroken lengths of CWR.

CAWS is only needed on multiple tracks where you have trains following each other and it is mainly to prevent one train colliding with the rear of another. This is not an issue on single tracks as usually only one train is every allowed in a section between loops.

shaunandelly

A Dub in Glasgo wrote: »

Most axle counters are electronic therefore there is no sound when the wheels go over them. I have never heard the sound you refer to above. Maybe you mean treadles which are used with level crossing systems although I am not so sure you can hear the treadle being pressed by the wheels?

I think you refer to the AWS or Automatic warning System. A long time since I've been on a uk train and I'm not sure if it changed with overhead electrification but any preceding signal at caution/stop would activate an in cab noise and yellow and black visual indicator. The driver would be required to acknowledge otherwise the brakes would be auto activated.

A Dub in Glasgo

AWS is still in use

Losty Dublin

In cab signal systems were intended for trains traveling at 100MPH+ speeds. The theory is that when a train travels any faster, driver isn't able to accurately see colour light signals so in cab display's need to be fitted. CAWS doesn't cost any more than other in cab signaling or protection systems to fit; new cabs actually have space and wiring for these to be fitted as specified by the operator/s.

shaunandelly

In the UK there is no line speed requirement for AWS it is an integral part of the signalling system. Was used for both mechanical and electro mechanical signalling. Line speed, capacity etc and therefore stopping distances meant the use of double yellow and flashing yellow aspects.

Our man in Havana

Also there are portable AWS magnets for enforcing TSRs.

Hungerford

I finally found an old Iarnrod Eireann presentation with the data the OP was looking for.

CTC areas:
The entire Belfast, Cork and Limerick lines plus the following sections:
Dublin-Maynooth; Dublin-Greystones; Dublin-Athy; Dublin-Ballinasloe; Athlone-Knockcroughery; Athlone-Moate [disused]; Mallow-Banteer.

Mini-CTC areas:
Maynooth-Sligo; Greystones-Rosslare; Athy-Waterford West; Ballinasloe-Galway; Knockgroughery-Westport/Ballina; Banteer-Tralee; Limerick-Athenry.

Mechanical signalling:
Passenger: Waterford West-Waterford; Limerick Jct-Waterford West; Ballybrophy-Killonan Jct; Waterford-Rosslare Strand [services suspended].
Others in service: Cork yard; Drogheda-Tara Mines.
Disused lines: Tara Jct-Kingscourt; Moate-Mullingar; Waterford-New Ross and Limerick-Foynes

Dublin Spotter

I read that Waterford-West-Waterford is due to be upgraded to CTC system as they are planning on only haveing one track for both Limerick J and Dublin between from Waterford West to the station and not the two and all the crossovers the departures to Dublin have to make which has it restricted to 20mph. Anyone know if it will happen or not?

Our man in Havana

More chance of Gerry Adams being elected Taoiesach.

Dublin Spotter

Then its time for me to leave the country..