rippled railhead

[richardio123]

Because AFAIK the Croydon service is nowhere near as intensive, or as big.

Your right Croyden Tram link is 17 miles compared to Metrolink's 47.7 Miles

 

[transmanche]

Because AFAIK the Croydon service is nowhere near as intensive, or as big.

Well the Metrolink network is, what, about three times the size of Tramlink? And it has about three times the number of trams. But the size or intensity of the network isn't really important - it's how intensively each tram is operated, along with factors such as track quality.

So do Metrolink work their trams a lot harder than Tramlink?

 

[richardio123]

Well the Metrolink network is, what, about three times the size of Tramlink? And it has about three times the number of trams. But the size or intensity of the network isn't really important - it's how intensively each tram is operated, along with factors such as track quality.

So do Metrolink work their trams a lot harder than Tramlink?

I could imagine yes considering one tram can be working for example between East Didsbury and Rochdale Railway Station which is a 20 mile route from 6:00 till gone midnight on 80% segregated lines at 50mph

 

[transmanche]

I could imagine yes considering one tram can be working for example between East Didsbury and Rochdale Railway Station which is a 20 mile route from 6:00 till gone midnight on 80% segregated lines at 50mph

Is that any harder work on the tram than one doing exactly the same on a 10 mile route? Like I said, the size of the network isn't really important - it's how much work each tram does.

 

[richardio123]

Is that any harder work on the tram than one doing exactly the same on a 10 mile route? Like I said, the size of the network isn't really important - it's how much work each tram does.

Isn't that the same thing ?

 

[transmanche]

Isn't that the same thing ?

No.

So basically we're no further forward. The 4000s don't seem to have suffered from the same problems as the 5000s - but we don't know why and there's no evidence to suggest that the 5000s are worked any harder than the 4000s.

 

[Starmill]

Metrolink has always had quite a high proportion of high-speed running, and I daresay that the ration of 50mph running has increased with the new lines opening.

I'm not sure what would be more wearing, sustained 50mph stretches with stops 4-5 mins apart like you get on the Oldham-Rochdale line or the Altrincham line and having to stop every 2 minutes but still get going as fast as possible between stops to keep to time.

I suspect running doubles means more mileage is accumulated too - it would be interesting to compare figures for something like miles between failures both now and a few years down the line (of course, some M5000s have already been in service a good few years).

As to the hazard braking capability, I'd not argue with that. From your point of view, the more stopping force the better until you're physically thrown through the front window! But being stood up (as such a high % of passengers are on an M5000) it's quite something!

My concern about it came from this RAIB report - but may be unfounded as it was actually referring to a T68!

http://www.raib.gov.uk/cms_resources.cfm?file=/120530_R082012_Piccadilly_Gardens.pdf

43
The rate at which the brake builds up is known as the jerk rate; industry guidance (appendix A, reference 1) suggests that jerk rate be limited to 1 m/s^(3). This is to reduce the risk of passengers being hurt when hazard brakes are applied. The hazard brake on tram 1002 built up considerably quicker than 1 m/s^(3), indicating that its stopping time (and distance) from 7 mph (11 km/h) was relatively short. There were no reports of any passengers on the tram being injured as a result of the emergency stop.

Now, I would have thought that the hazard braking capability is at least the same and it feels like more than a T68 had? Were both fitted with magnetic track brakes, in addition to conventional brakes and regenerative braking (M5000 only)?

I'm not saying they should necessarily be reduced in strength (indeed, quite the opposite if this would make a repeat of the terrible incident in Piccadilly Gardens detailed in the report, and the others over the years, more likely) but it's a fine thing for the design of a tram to put the safety of it's passengers at risk for the sake of people who aren't looking where they're going!

 

[edwin_m]

Because AFAIK the Croydon service is nowhere near as intensive, or as big.

Like Metrolink, Tramlink includes a busy town centre section with some very tight curves, as well as quite a bit of 80km/h running on former railways. It doesn't have any long slowish street routes like Eccles or Ashton (or Airport in future) so the daily mileage may even be greater in Croydon.

The network isn't as big (29 stops IIRC), but the fleet is smaller too (about 30 trams) so the daily mileage and service hours of each vehicle will be similar to Manchester. And the daytime service through East Croydon looks to be about 22 trams per hour in each direction so not far short of the busiest parts of Manchester.

http://www.tfl.gov.uk/gettingaround/10355.aspx

Even though the network hasn't been extended since opening more vehicles were purchased over the last couple of years, so clearly they could not squeeze any extra work out of the existing fleet. It's possible this is due to poor reliability, which is partly why I asked the question, but I've not heard anything to suggest that and I've read that the new order was to increase service frequencies. See this link for example:

http://www.railwaygazette.com/news/single-view/view/stadler-wins-london-tramlink-tram-order.html

The original Bombardier trams were close copies of another design for Koeln, this one being used on the low-platform routes there. However I understand there is a lot of similarity between this and the high-platform design also supplied to Metrolink.

I was involved in testing and commissioning these trams and they pretty much worked "out of the box" on arrival in Croydon. I haven't had much opportunity to visit since then but I'm spending quite a bit of time in Croydon at present so I must find time to take an evening trip out on one of the faster bits of the network to see how the ride is!

The M5000 ride problems were evident soon after they went into service but the Croydon trams have run since 2000 so if they had any similar problem it would surely have appeared by now. As suggested it must either be down to some feature of the M5000 that isn't included in the CR4000 or down to the environment in Manchester.

 

[507 001]

I could imagine yes considering one tram can be working for example between East Didsbury and Rochdale Railway Station which is a 20 mile route from 6:00 till gone midnight on 80% segregated lines at 50mph

Don't forget that the Bury and Rochdale Routes are very steeply graded.

Metrolink has always had quite a high proportion of high-speed running, and I daresay that the ration of 50mph running has increased with the new lines opening.

I'm not sure what would be more wearing, sustained 50mph stretches with stops 4-5 mins apart like you get on the Oldham-Rochdale line or the Altrincham line and having to stop every 2 minutes but still get going as fast as possible between stops to keep to time.

I suspect running doubles means more mileage is accumulated too - it would be interesting to compare figures for something like miles between failures both now and a few years down the line (of course, some M5000s have already been in service a good few years).

I would say that the Altrincham line is more demanding than the Rochdale line with constant full power acceleration followed by quite hard braking, the timetable doesn't help here. I would say that the Bury line would be the most demanding due to the gradients, high speed running and frequent stops.

As to the hazard braking capability, I'd not argue with that. From your point of view, the more stopping force the better until you're physically thrown through the front window! But being stood up (as such a high % of passengers are on an M5000) it's quite something!

My concern about it came from this RAIB report - but may be unfounded as it was actually referring to a T68!

http://www.raib.gov.uk/cms_resources.cfm?file=/120530_R082012_Piccadilly_Gardens.pdf



Now, I would have thought that the hazard braking capability is at least the same and it feels like more than a T68 had? Were both fitted with magnetic track brakes, in addition to conventional brakes and regenerative braking (M5000 only)?

I'm not saying they should necessarily be reduced in strength (indeed, quite the opposite if this would make a repeat of the terrible incident in Piccadilly Gardens detailed in the report, and the others over the years, more likely) but it's a fine thing for the design of a tram to put the safety of it's passengers at risk for the sake of people who aren't looking where they're going!

Yes I agree that from a standing passengers point of view that it can be quite harsh (I've actually slid off of one of the sideways facing seats during an ATS trip and they arent as harsh as a hazard application!).

Like Metrolink, Tramlink includes a busy town centre section with some very tight curves, as well as quite a bit of 80km/h running on former railways. It doesn't have any long slowish street routes like Eccles or Ashton (or Airport in future) so the daily mileage may even be greater in Croydon.

The network isn't as big (29 stops IIRC), but the fleet is smaller too (about 30 trams) so the daily mileage and service hours of each vehicle will be similar to Manchester. And the daytime service through East Croydon looks to be about 22 trams per hour in each direction so not far short of the busiest parts of Manchester.

http://www.tfl.gov.uk/gettingaround/10355.aspx

Even though the network hasn't been extended since opening more vehicles were purchased over the last couple of years, so clearly they could not squeeze any extra work out of the existing fleet. It's possible this is due to poor reliability, which is partly why I asked the question, but I've not heard anything to suggest that and I've read that the new order was to increase service frequencies. See this link for example:

http://www.railwaygazette.com/news/single-view/view/stadler-wins-london-tramlink-tram-order.html

The original Bombardier trams were close copies of another design for Koeln, this one being used on the low-platform routes there. However I understand there is a lot of similarity between this and the high-platform design also supplied to Metrolink.

I was involved in testing and commissioning these trams and they pretty much worked "out of the box" on arrival in Croydon. I haven't had much opportunity to visit since then but I'm spending quite a bit of time in Croydon at present so I must find time to take an evening trip out on one of the faster bits of the network to see how the ride is!

The M5000 ride problems were evident soon after they went into service but the Croydon trams have run since 2000 so if they had any similar problem it would surely have appeared by now. As suggested it must either be down to some feature of the M5000 that isn't included in the CR4000 or down to the environment in Manchester.

What is the average service frequency of Tramlink?

I wonder if the extra height of the high floor M5000s is part of the problem, especially if the suspension is designed for low floor units.