Luas

godtabh

Is the Luas working today?

Some one in work said they werent and I couldnt see anything in the www.luas.ie site to suggest it wasnt.

MarkoP11

Green line is shutdown for some reason, no further details yet

Dublin Bus will honor tickets

godtabh

MarkoP11 wrote:

Green line is shutdown for some reason, no further details yet

Dublin Bus will honor tickets

Where did you find this out?

mollser

MarkoP11 wrote:

Green line is shutdown for some reason, no further details yet

Dublin Bus will honor tickets

I can hear the announcements out the window, they're saying there's a fault with a tram, i think they are running between dundrum and sandyford only, but its been this way since lunchtime - mustve been a crash.

Oh - I think its back in action - she just said there's a number of trams on route

godtabh

It better be back on. Dont fancy getting the bus from Sandyford in this traffic

Bluetonic

17/2/2006 LUAS services have resumed on the Green Line

RAIL ALERT: LUAS services have resumed on the Green Line with 20 min delays in both directions.

www.aaroadwatch.ie

godtabh

Bluetonic wrote:

www.aaroadwatch.ie

Nice one.

Checked the aa site but no info on that.

Didnt know about that site

mollser

Green line banjaxed again tonight - one broke down at 5:25 on harcourt st, and over an hour later they still can't budge it.

The breakdown's are occurring almost daily on this line now, and coupled with frequent gaps of 8/9 mins at rush hour (causes havoc), whats happening it?

Red Alert

A few points:

The trams have protection circuits which prevent say a tram moving with open doors or the driver with his hand off the lever. Three switches control these circuits and they're located left of the driver. One has to cut the seal and turn the switch (obviously under supervision and with no passengers aboard) - I wonder if this has been done?

There could be a signalling issue, although the trams aren't interlocked to the signals. I very much doubt they'd let a faulty signal prevent operation. A garda or Connex person could stand there to override it, it could also be switched from base.

It's possible the tram isn't picking up the induction loop signals. (The loops are in the road and they both sense and are sensed by a tram). Again this needn't be a show-stopper.

The tram's motors could be faulty or the control gear could be faulty. Very unlikely to cause a total shutdown to occur.

The overhead power supply could be faulty. Again very unlikely, and if a section's faulty it's usually possible to electrically strap it to the neighbouring one and run with reduced accelerating.

Major flaw is that there's no emergency crossover after beechwood which is totally idiotic. No excuse!

MarkoP11

The Luas trams are a well proven design they are maintained by the manufacturer thus a high level of failures is not acceptable

The trams have two independent traction packages, either of which is more than capable of moving the tram assuming the pantograph and main circuit breaker sare ok.

The power supply circuit should be able to sustain full unrestricted operation with the loss of one substation. Luas seems not to allow this as it was caught out early on as it appears Luas substations do not have dual grid feeds. The DART system has dual feeds, failure of both is a once in 50 years event, Luas was in the dark in a matter of a week of opening

All rail vehicles have override and isolation switches its quite amazing how much stuff you can switch off and still keep in service, the trusty DART can run for quite a while if the auxiliary electrically supply dies. Typically cetain isolation switches can only be used with the permission of a supervisor, certain switches disable safety equipment which may be allowed if two drivers are present

The signals can be overidden by calling in by radio. If the induction loop system failed on the tram it could leave the tram in a fail safe mode not capable of more than a walking pace, even then the tram could set back to the Green as each cab has its own transponder

Ideally a crossover just below Harcourt Street stop would save a lot of bother, all the crossovers are trailing so you can't even go to single line working in some cases

mollser

It broke again this morning at the Ranelagh station - took him 15 mins to get it going, it seemed to be a door fault this time, one which wouldn't close properly.

Walking up to Beechwood in the end to get it yesterday evening, a couple of things struck me.

1) How unprepared for any sort of breakdown they appear to be.

2) At beechwood, the driver had to pull out of the station, stop the tram, disembark with a stick, manually switch the lines over so he could cross over to the outbound line. Surely they could have had a staff member to do this, never mind the fact its not automated?? Everyone on board had a good laugh, it was like the ould days

3) Surely more frequent cross over points would enable them to continue services from no more than 2 stops away from where the breakdown occurs?

MarkoP11

The design of the system does not allow single line working
Since each tram is a single unit a fault can be a show stopper
Its not unusual that emergency crossovers are manual, that said the heavy rail network last installed such in 1976, everything since is remotely controlled
A interesting point to note is not one single emergency crossover is shown on the plans between Sandyford and Cherrywood

If a door lets go on a train its very simple 5 minutes trying to fix if that fails then throw everyone off, isolate the safety system and ditch the train in the nearest siding. Connex and Alstom seriously need to get there act together. Staff should be trained in basic fault diagnosis and rectification, there should be at least one technican travelling as a passenger on the system

bringitdown

I know this has been mentioned, why is there no crossover after beechwood? One would assume there is plenty of space for one between Ranelagh and Charlemont?

The fact that the one at Beechwood is not automated is pathetic.

Red Alert

Common sense would say there'd be no need for the crossover at beechwood to be automated if it functioned on spring-return. I.e. there's a big spring which keeps the points in the right position for a facing tram. the other direction will just trail through and push them open. Google for Croydon Tramlink for an explanation. Obviously the sensible thing to do would be to power them all so that the Red Cow can switch any point on the system - odd enough that they installed a CCTV camera there along with some sort of control box if the points aren't automatic.

Can someone explain why we couldn't go single line by changing to the other track. Can the trams drive in reverse to go over the crossover or would this need two cab changes?

I noticed the PIS was set for Beechwood, did this announce Beechwood as the last stop etc. and do the destination countdowns? I saw the tram from beneath the LUAS bridge yesterday.

EDIT: having de-trained everybody can the driver request permission to cut the Door Interlock switch located on the left electrical panel?

Victor

The doors do seem to be a recurring problem, whether its people sticking things in them (is this an excuse?) or the door just jamming. I'm not sure if the doors can be isolated.

I've seen trams operating to visual rules with two trams on the northbound platform at Harcourt (I was on one of the trams trailing a "door jam").

Trams can reverse, this is how the de-railing occured at St. Stephen's Green, the southbound tram left prematurely, joined the other track, where the inbound trams was, the driver reversed and de-railed. Since then its strictly enforced that the arriving tram must be at the platform beofr ethe departing tram can move.

Red Alert

The trouble with the doors is their mechanical complexity. They're electrically driven so need some neat gearing to allow the motor to move them, unlike the bus doors which just use air in a pneumatic ram. They also have a positive lock at the end of their travel, unlike a bus where air pressure keeps the door open or closed. They really resemble the doors you'd see in a Lift rather than anything else, except that they also pop out before opening fully.

They seem to be plagued by a problem that affects older lifts - they appear to have a rubber contact sensing strip and some sort of force detector in the mechanism to stop them in case of an obstruction. These seem to fail a lot.

I saw a red sign on a door once saying "Door out of order", and I also saw the same sign on a lift that was kaput at Kilmacud. Obviously there's enough door failures to warrant printing these signs :eek: