Level Crossings @ Lansdowne, Sandymount, Sydney Parade: Excessive Length of Time Down

VANG1

What’s going to happen when the frequency of trains increases to one every 5 minutes. I presume our highly paid politicians have no plans made

lucernarian

Vic_08 wrote: »

The only irony is that you appear not to understand the definition of ignorance.

The OP was and despite having the topic explained to him by a number of posters, still remains ignorant of how and why railway crossings do not operate how he would like them to.

I'd bet you wouldn't take kindly to someone turning up, admitting they knew nothing about your line of work and then spouting off about how you are doing everything wrong and they are here to put you straight.

Yes my response wasn't polite. Ask a polite question; get a polite response, rant about how the experts in a field you know nothing about are crap at their jobs; get put in your place.

"get put in your place" Is this a schoolyard? I don't see any experts here talking about rail safety and signalling, unless they might step forward with their qualifications, or references for their knowledge?

You're also taking points made after the fact, as justification for the bitchy and mean tone of your reply (the 2nd post of this thread). I re-read the first post, I saw someone who was disgruntled on a personal level and wanted to understand more about the subject - throwing out ideas in the hope they could be discussed further. Where's the rude and ranty post you're referring to? Or is this just a handy straw man for post-hoc justifying of your rude response?

People who want to get a reasonable answer to something they know nothing about don't generally start by offloading a bunch of derogatory opinions of the people who run the system they wish to know about.

Again, can you cite where, in the first post, these derogatory comments are? If it's "it's very clearly just been done incorrectly and could proabbly be massively improved with very little effort"..... Is this honestly the bit that got you triggered? Cause it's the sharpest criticism I found and if that draws out such vitriol from you, I suggest you get a thicker skin.

IE 222

lucernarian wrote: »

In fairness nothing, there's no (good) reason for people to reply like assholes or speak in a way most folks wouldn't dream of doing with colleagues, customers, acquaintances or even strangers.

I think the salient part of the question is obvious. Why would a barrier need be closed for 3 mins before a train arrives while in the Netherlands I observed it closed for 90 seconds on a track that had a 100kph speed limit? Like, it's not a rhetorical question, there must be specific reasons for why this happens especially at the likes of Sydney Parade.

Was there a station beside the crossing?
Was there another crossing within 1km both sides of it?
How busy was the crossing with non rail traffic?
Did the line run a mixed fleet of trains i.e electric and diesel?

For a southbound train at Sydney Parade the crossing wouldn't be down for much more than a min. It's only if a northbound train was going to enter the block before the gate reopening that they remain closed.

Gates must be opened for a min of 9 seconds otherwise they must remain down. This is how some trains are brought to a halt.

trellheim

I'm not getting into blocks and overlaps

Id like to ask a slightly different question

The D&KR has been running for 185 years and these LC's have been in place for a very long time

was there not pedestrian overbridges at these locations before or were they removed for electrification or has it always been this way

GerardKeating

trellheim wrote: »

I'm not getting into blocks and overlaps

Id like to ask a slightly different question

The D&KR has been running for 185 years and these LC's have been in place for a very long time

was there not pedestrian overbridges at these locations before or were they removed for electrification or has it always been this way

Pre-electrification, there was a "Pedestrian Overbridge" at Lansdowne Road Station, but i think it could be only be access from the platforms, it was replaced with an underpass, none of the other crossing ever had any other means of crossing the track. The is another underpass on the foot path along the River.

cdaly_

GerardKeating wrote: »

Pre-electrification, there was a "Pedestrian Overbridge" at Lansdowne Road Station, but i think it could be only be access from the platforms, it was replaced with an underpass, none of the other crossing ever had any other means of crossing the track. The is another underpass on the foot path along the River.

There was one crossing (since closed) at the West Pier Dun Laoghaire. The crossing was a request one, only opened when a vehicle wished to cross. Alongside this was a pedestrian gate which was normally open and only locked when one of the relatively few trains passed.

Sam Russell

GerardKeating wrote: »

Pre-electrification, there was a "Pedestrian Overbridge" at Lansdowne Road Station, but i think it could be only be access from the platforms, it was replaced with an underpass, none of the other crossing ever had any other means of crossing the track. The is another underpass on the foot path along the River.

There has a always been a pedestrian bridge at Sydney Parade accessible from the station. The Southbound platform could only be accessed by that bridge, be but in recent years, a pedestrian access has been built for southbound passengers. Furthermore, the old cast iron pedestrian bridge, which was clad in nasty iron sheeting, has been replaced by a very nice one. However, it is also only accessible from the platform.

Just to be clear, the SB trains cause the gates to close about 2 min before they arrive, and the gate opens straight after the train clears the gates. The NB trains trigger that gates about 3 mins before they arrive at the platform, where a stopping train will wait for a min or two. The gate opens when the train has cleared the gates and travelled a few hundred metres. Trains in both directions run on single yellow lights because the are gates in both directions.

If the Merrion Gates project was completed, it would not be a problem.

blobert

IE 222 wrote: »

I don't get why your so determined to challenge this.

Couple of reasons. Mainly from a selfish personal perspective, I'm spending 10-15+ minutes standing at these barriers every day watching them go down several minutes before a train rolls by at <20kmph. Yesterday I was stuck for over 15 minutes driving 200m with a screaming baby in the car beside me trying to get home. I'm planning to live where I live for rest of my life, those minutes will quickly add up to hours and days of life wasted. There's thousands of other people stuck at these barriers every day also so I'm sure there's lots of other people negative affected by it also.

Also from a practical point of view, I like solving problems and improving things and in my businesses have managed to improve a lot of things that were initially described as "can't be improved/just the way it is etc" so I like a challenge.

With the greatest respect to those with far superior knowledge of how this stuff works and who have posted to say it can't be done, I'd be absolutely amazed if it's not possible to improve the situation in some meaningful way from what it is at the moment. Now obviously the real question is how hard that is to do and how expensive. I think if there's a relatively simple solution that's far cheaper than building bridges then that's worth trying.

Just to sum up where I am with this at the moment:

(1) I'm hoping someone can very simply explain how the system for the barriers works at the moment. As per comments previously it seems to lower when a train hits a predetermined point on the track maybe 1.3-1.5km from the crossing. Where this is placed is determined by calculating how long it could take for the fastest train going at the line speed limit would take to reach the junction. Based on Wikipedia (as per my last comment) this seems quite an outdated system.

Does this sound correct?

(2) The line speed limit is currently set to 40mph/65kmph, this means the point that starts the barriers dropping has to be quite far from the junction to allow for the sceanior of a 40mph train. But the reality is that the trains traveling on this 2.5km stretch of track do not travel at anything like this speed, a lot of the time they are literally crawling along it. This is why there is a massive gap between the barriers going down and the train arriving, because it's configured for trains going 2-3 time faster than they do in reality.

(3) Therefore if you decrease the line speed limit to somthing like 30kmph you can move the point that starts the junction closing much closer to the junction itself, as now the fastest train will need less than <1/2 the stopping distance of this hypothetical 40mph train it's currently set for. Lowering the speed limit does not affect any trains as they are all going at a much lower speed anyway so passengers are not affected.

(4) Now the junction barriers don't start to close till the trains are much closer to the junction, so instead of closing 2.5-3 mins before the train arrives they might close 1 to 1.5mins. This still allows for the trains to safely stop if needs be in an emergency and roughly halves the length of time that the barriers are down without negatively affecting passengers and while making a massive improvement to traffic in the area.

If anyone that works at Irish Rail or has a good idea of how the current system works would give their comments on the above summary I'd appreciate it.

Thanks!

goingnowhere

Line speed limit is 100kph and has been for 35 years and trains passing through Merrion Gates assuming they get clear signals (as is the design) should be at above 90kph)

The rules on the DART are based on
1. Level crossing must be CCTV inspected and are interlocked with the signaling system
2. Full overlap protection is provided, so if gates are open, train is halted 200m from gates

Elsewhere in the world (where the instances of level crossing accidents are much greater) the gates are timed to drop and be down 30 seconds before a train passes based on the fastest train


For Merrion Gates the logic is

Depart Blackrock, train gets a yellow signal which enforces a 50kph limit before Booterstown
Loss of 30 seconds due the enforced speed limit due signals protecting Merrion Gates.
Stops in Booterstown with a red signal.
Doors open
Merrion Gates are requested based on a timer
Sydney Parade gates requested based on a timer
Gates close and are confirmed closed by CCTV
Signal clears to Yellow, next signals are Red (BN33), Red (BN31)
Driver moves off
Sydney Parade gates are confirmed closed by CCTV
Signal clears to Green, next signals are Double Yellow (90kph), Yellow (50kph) this gives a profile where the permitted speed is greater than the braking curve
DART even if it has past the first signal will pick up that the signal was retrospectively Green and give the driver 100kph
Train arrives Sydney Parade with gates down and a yellow signal, the yellow signal is because Sandymount gates are not down
Timer runs to call Sandymount gates
Sandymount gates are confirmed closed by CCTV
Train departs, the signal at Sydney Parade will move to double yellow (90kph)
Next signal is yellow as Serpentine Ave gates are not closed, these trigger


There is an upgrade to the DART ATP system coming which should allow DART trains to travel much faster when faced with restrictive signals, giving a braking curve based on the red signal ignoring all others instead of the current static speed control system which was very clever for 1984 but is prehistoric by current standards but still exceptionally reliable

CatInABox

blobert wrote: »

Couple of reasons. Mainly from a selfish personal perspective, I'm spending 10-15+ minutes standing at these barriers every day watching them go down several minutes before a train rolls by at <20kmph. Yesterday I was stuck for over 15 minutes driving 200m with a screaming baby in the car beside me trying to get home. I'm planning to live where I live for rest of my life, those minutes will quickly add up to hours and days of life wasted. There's thousands of other people stuck at these barriers every day also so I'm sure there's lots of other people negative affected by it also.

If this is true, the best thing that you can do is contact your local representatives and push them to progress the Merrion Gates project. Right now, they're only hearing from locals opposed to the project.

As to Irish Rail reducing the time the gates are closed, it's not going to happen. They're a pretty conservative company, and won't put the lives of hundreds of people in danger just to enable a tiny increase in the number of cars getting through the gates.

magicbastarder

blobert wrote: »

I've recently moved to live right beside Sydney Parade train station.

you recently moved to somewhere with possibly the best train service in the country, and are now finding fault with how the trains are impacting your life.

land values along that line are higher because of the train service, but if you're not actually using the train, you may have spent more than you needed to, because you're essentially paying for a service you don't seem to use all that much?
it's like moving out beside the airport and being surprised that planes make noise on takeoff.

we have good friends living within spitting distance of one of these level crossings; i've never heard them complain of it being an issue for them. but i suspect that's a consequence of adaptation; they probably just know to expect it and get on with things.

trellheim

Perhaps press for a pedestrian overbridge and the level crossings removed with your council and TD

This topic comes up time and again here, it was a long running problem at Reillys bridge in Cabra/Ratoath road until... guess what... a brand new overbridge was built and the Level crossing eliminated , now you never hear about it. Have a long long read back here ( there were many posts about it ) and do the research

Sam Russell is trying to point you at the same solution for Merrion Gates ... so why not read up on that, you seem to want to know the details so why not look into it , as I said the railways been there for 185 years

magicbastarder

magicbastarder wrote: »

we have good friends living within spitting distance of one of these level crossings; i've never heard them complain of it being an issue for them. but i suspect that's a consequence of adaptation; they probably just know to expect it and get on with things.

an aside - we reasonably regularly head out to our friends and it's a running joke with myself and my wife that our presence activates the level crossing we have to cross to get to our friends' house (we're lucky that we have a bus service that only leaves us with about 500m walk in total to get there).
i'd say in the last ten times we've approached that level crossing, the gates have come down with us only a very short distance away, on at least half the occasions.

Sam Russell

trellheim wrote: »

Perhaps press for a pedestrian overbridge and the level crossings removed with your council and TD

This topic comes up time and again here, it was a long running problem at Reillys bridge in Cabra/Ratoath road until... guess what... a brand new overbridge was built and the Level crossing eliminated , now you never hear about it. Have a long long read back here ( there were many posts about it ) and do the research

Sam Russell is trying to point you at the same solution for Merrion Gates ... so why not read up on that, you seem to want to know the details so why not look into it , as I said the railways been there for 185 years

Here is a link to a thread on Infrastructure that deals with it.

https://www.boards.ie/vbulletin/showthread.php?p=101479541

lucernarian

goingnowhere wrote: »

Line speed limit is 100kph and has been for 35 years and trains passing through Merrion Gates assuming they get clear signals (as is the design) should be at above 90kph)

The rules on the DART are based on
1. Level crossing must be CCTV inspected and are interlocked with the signaling system
2. Full overlap protection is provided, so if gates are open, train is halted 200m from gates

Elsewhere in the world (where the instances of level crossing accidents are much greater) the gates are timed to drop and be down 30 seconds before a train passes based on the fastest train


For Merrion Gates the logic is

Depart Blackrock, train gets a yellow signal which enforces a 50kph limit before Booterstown
Loss of 30 seconds due the enforced speed limit due signals protecting Merrion Gates.
Stops in Booterstown with a red signal.
Doors open
Merrion Gates are requested based on a timer
Sydney Parade gates requested based on a timer
Gates close and are confirmed closed by CCTV
Signal clears to Yellow, next signals are Red (BN33), Red (BN31)
Driver moves off
Sydney Parade gates are confirmed closed by CCTV
Signal clears to Green, next signals are Double Yellow (90kph), Yellow (50kph) this gives a profile where the permitted speed is greater than the braking curve
DART even if it has past the first signal will pick up that the signal was retrospectively Green and give the driver 100kph
Train arrives Sydney Parade with gates down and a yellow signal, the yellow signal is because Sandymount gates are not down
Timer runs to call Sandymount gates
Sandymount gates are confirmed closed by CCTV
Train departs, the signal at Sydney Parade will move to double yellow (90kph)
Next signal is yellow as Serpentine Ave gates are not closed, these trigger


There is an upgrade to the DART ATP system coming which should allow DART trains to travel much faster when faced with restrictive signals, giving a braking curve based on the red signal ignoring all others instead of the current static speed control system which was very clever for 1984 but is prehistoric by current standards but still exceptionally reliable

Thanks for the detailed explanation!

Sam Russell

Irish Rail cannot be expected to upgrade their signaling systems just because there is an advance in technology. The Dart was designed and implemented in 1982 and uses technology that was OK for that time. The original Dart service was a two car train service every 15 or 20 mins, but now is an eight car service with a ten minute frequency in both directions.

The gates at SP close 3 minutes before a NB and 2 mins before a SB, so they could be down for five minutes per ten minutes. If the service improves to 8 services per hour per direction, the level crossings will barely open. What will we do then?

CatInABox

Sam Russell wrote: »

The gates at SP close 3 minutes before a NB and 2 mins before a SB, so they could be down for five minutes per ten minutes. If the service improves to 8 services per hour per direction, the level crossings will barely open. What will we do then?

Indeed, Irish Rail have stated in their DART expansion plans that their eventual ambition is to increase the frequency of service to every 5 minutes. That's a minimum of 12 trains per hour per direction, not including any of the commuter trains either. If they don't remove the crossing before then, then the crossings simply won't open at all.

blobert

goingnowhere wrote: »

Line speed limit is 100kph and has been for 35 years and trains passing through Merrion Gates assuming they get clear signals (as is the design) should be at above 90kph)

The rules on the DART are based on
1. Level crossing must be CCTV inspected and are interlocked with the signaling system
2. Full overlap protection is provided, so if gates are open, train is halted 200m from gates

Elsewhere in the world (where the instances of level crossing accidents are much greater) the gates are timed to drop and be down 30 seconds before a train passes based on the fastest train


For Merrion Gates the logic is

Depart Blackrock, train gets a yellow signal which enforces a 50kph limit before Booterstown
Loss of 30 seconds due the enforced speed limit due signals protecting Merrion Gates.
Stops in Booterstown with a red signal.
Doors open
Merrion Gates are requested based on a timer
Sydney Parade gates requested based on a timer
Gates close and are confirmed closed by CCTV
Signal clears to Yellow, next signals are Red (BN33), Red (BN31)
Driver moves off
Sydney Parade gates are confirmed closed by CCTV
Signal clears to Green, next signals are Double Yellow (90kph), Yellow (50kph) this gives a profile where the permitted speed is greater than the braking curve
DART even if it has past the first signal will pick up that the signal was retrospectively Green and give the driver 100kph
Train arrives Sydney Parade with gates down and a yellow signal, the yellow signal is because Sandymount gates are not down
Timer runs to call Sandymount gates
Sandymount gates are confirmed closed by CCTV
Train departs, the signal at Sydney Parade will move to double yellow (90kph)
Next signal is yellow as Serpentine Ave gates are not closed, these trigger


There is an upgrade to the DART ATP system coming which should allow DART trains to travel much faster when faced with restrictive signals, giving a braking curve based on the red signal ignoring all others instead of the current static speed control system which was very clever for 1984 but is prehistoric by current standards but still exceptionally reliable

Thanks very much for the very detailed reply, I appreciate it.

A lot of it is a bit too technical for me, just looking to understand it on a very basic level.

I'm still somewhat in the dark as to how the signal to close the junction gates is given.

For the DART you say when the DART is stopped in Booterstown (last station before Merrion Gates) the gates are requested "on a timer". Does this happen when it drives over the tracks there or some other system? If so are there 2 different systems that close the gates, one for DART and one for other trains.

What I'm still hoping to get at is what it is that triggers the junctions closing and how possible it is to change that without massive effort, ie if a train driving over somthing at Booterstown station is what triggers the Merrion Gates closing can this in theory be moved.

The fact that the line limit is 100kmph would very much tie in with my belief that that's a big cause of the problem as is, that the system is set up to be safe for 100kmph trains and hence the massive delay between barriers going down and train actually arriving.

Again I'd agree that the closing of these junctions and building of a bridge as planned previously makes complete sense and I'll try to lobby to get this done. But I'm also aware of the level of slowness of anything being done on an infrastructure basis (ie we could be a long time waiting) so it might make sense to first do any quick fixes that are less work than building bridges/underpasses if they are possible.

goingnowhere

The trigger point for the gates is a function of the train type

The trigger can either be a train passing a fixed point or a fixed time after it past a fixed point. The signalling system is split into sections so the borders between sections may not match with the optimum trigger points so a timer is used, based on last known position

In the case of the DART area everything is scheduled by a computer based on the above triggers, the computer accounts for the need to ensure a minimum opening time for the gates as well as allowing only a single train in each direction per closure. Its non trivial.

trellheim

But I'm also aware of the level of slowness of anything being done on an infrastructure basis (ie we could be a long time waiting)

ummm.... was it not the locals that kiboshed Merrion Gates programme last time ... its not the State or CIE/IR you are waiting on here

MJohnston

blobert wrote: »

it might make sense to first do any quick fixes that are less work than building bridges/underpasses if they are possible.

Buddy, I hate to tell you, but this right here is a big problem with your thinking. Reducing safety and efficiency of rail services would not be a fix. It'd be a cludge, a bad compromise. What you're proposing would be breakages - they'd make the system worse to benefit a tiny few at the expense of a large majority.

I don't know why you would ever expect support for these proposals on a forum like this! You might be better off contacting the AA or some other car user lobby group.

machaseh

If you just go by train rather than by car, you won't have to wait at the level crossing !

blobert

goingnowhere wrote: »

The trigger point for the gates is a function of the train type

The trigger can either be a train passing a fixed point or a fixed time after it past a fixed point. The signalling system is split into sections so the borders between sections may not match with the optimum trigger points so a timer is used, based on last known position

In the case of the DART area everything is scheduled by a computer based on the above triggers, the computer accounts for the need to ensure a minimum opening time for the gates as well as allowing only a single train in each direction per closure. Its non trivial.

Thanks very much for the reply on this.

Its sounds as though the complex part of this is having all the variables working together, ie if you change somthing it does not break somthing else.

But would I be correct in saying if you were to make changes to it the main expense would be moving the fixed point signals, ie the timer changes would just be a chase of changing somthing from 60 to 30 seconds on the system?

While it might be non trivial to do in terms of the level of complication, I'm guessing the actual cost in €€€ terms would be very low, certainly vs the cost of building tunnels under junctions?

cdaly_

CatInABox wrote: »

Indeed, Irish Rail have stated in their DART expansion plans that their eventual ambition is to increase the frequency of service to every 5 minutes. That's a minimum of 12 trains per hour per direction, not including any of the commuter trains either. If they don't remove the crossing before then, then the crossings simply won't open at all.

blobert wrote: »

Thanks very much for the reply on this.

Its sounds as though the complex part of this is having all the variables working together, ie if you change somthing it does not break somthing else.

But would I be correct in saying if you were to make changes to it the main expense would be moving the fixed point signals, ie the timer changes would just be a chase of changing somthing from 60 to 30 seconds on the system?

While it might be non trivial to do in terms of the level of complication, I'm guessing the actual cost in €€€ terms would be very low, certainly vs the cost of building tunnels under junctions?

See CatInABox's reply above...