Metrolink take steps to improve M5000 ride quality

[northwichcat]

The T68s were responsible for creating much of the track profiles which have caused the M5000s to sway when travelling at speed on several parts of the network. Recent work has seen several trams being fitted with different profile wheels and dampening springs to improve the ride quality. Other steps have been taken to tamp and re-profile the running lines to add to this process. Regular passengers will have noticed the smoother ride from Timperley to Brooklands and the reduced width of shine on various lines where the T68s have never been – e.g. to Oldham and Rochdale. This re-profiling of track and wheels will in time bring smoother tram journeys across the network.

http://www.mcrua.org.uk/chairmansblog/2014/06/03/mcrua-metrolink-ratp-dev-liaison-meeting-may-2014/

So it sounds like while track profiles of the T68s were an issue they weren't the only issue affecting the M5000's ride quality at higher speeds.

 

[507 001]

I get the impression the T68s are being used as scapegoats.

I think it's more to do with the fact that the M5000s have been delivered with a dodgy wheel profile.

As I've said before, there are places on the Rochdale and East dids lines where ride quality isn't great and is only deteriorating.

 

[freetoview33]

Well hopefully with the woek being done this will see things improve

 

[Bill Stanier]

The ride quality of the new trams is absolutely appalling! I don't know how the poor old driver managed to stay in his seat between Altrincham and the City, and then on another new tram out to Bury! The journey back on 'old' trams was far, far smoother.

The driver told us it was because the new trams have much less sophisticated suspension than the air suspended old trams.

Sounds like cost-cutting in the new fleet to me!

 

[fgwrich]

Interesting given that this is another Bombardier product that has issues - The M5000s are an updated version of the Cologne Flexity Swift (and a cousin of the low floor CR4000s used in Croydon). Does anyone of the other Bombardier built trams suffer ride quality issues, like the Blackpool Flexity's or is it just the M5000?

I did notice how TFGM tried to use the T68s as scapegoats too - Surely, we should know by now that everything new is wonderful and doesn't come with issues?

 

[northwichcat]

Interesting given that this is another Bombardier product that has issues - The M5000s are an updated version of the Cologne Flexity Swift (and a cousin of the low floor CR4000s used in Croydon). Does anyone of the other Bombardier built trams suffer ride quality issues, like the Blackpool Flexity's or is it just the M5000?

Metrolink is effectively a combination of converted train lines, off-road tram lines and on-road tram lines while the M5000s seem a product most suited to on-road tram lines, which Metrolink doesn't have a lot of and not well suited to the converted train lines, which Metrolink has a lot of.

 

[DynamicSpirit]

On a related note, I was struck by this paragraph in the blog linked to in the opening post of this thread:

http://www.mcrua.org.uk/chairmansblog/2014/06/03/mcrua-metrolink-ratp-dev-liaison-meeting-may-2014/

The Metrolink timetable has changed little since its inception in 1992 but with changes in stops, line and tram speeds (the M5000s are slower than the T68s) plus a number of long-term “temporary” speed limits due to track conditions, a re-cast of the timetable next year will look at updating timings and thus bring the actual timetable closer to the planned timing

Buying new trams that are slower than the old ones, and which therefore require you to slow the timetable down further, doesn't quite strike me as the most obviously sensible purchase decision you might make!

 

[northwichcat]

Buying new trams that are slower than the old ones, and which therefore require you to slow the timetable down further, doesn't quite strike me as the most obviously sensible purchase decision you might make!

For clarification - the two types of tram have same maximum speed but the T68s were capable of doing Altrincham-Deansgate and Victoria-Bury faster.

 

[Bill Stanier]

For clarification - the two types of tram have same maximum speed but the T68s were capable of doing Altrincham-Deansgate and Victoria-Bury faster.

Is that because the new trams would come right off the rails due appalling riding if run at max speed?

 

[northwichcat]

Is that because the new trams would come right off the rails due appalling riding if run at max speed?

Well Metrolink have lowered the line speeds in places. Prior to the T68 withdrawal some of the speed restriction signs said 'M5000 only'

 

[Bill Stanier]

Well Metrolink have lowered the line speeds in places. Prior to the T68 withdrawal some of the speed restriction signs said 'M5000 only'

Someone at Metrolink seems to have some explaining to do. Who signed off the purchase, and what incentivised them to do so? I did write to them to ask about their reasons for this apparent degradation in tram technology, but needless to say they didn't even reply. :roll:

 

[WatcherZero]

You mean same tram technology as in Croydon, DLR and some models of london Underground stock?

 

[Manchester77]

Someone at Metrolink seems to have some explaining to do. Who signed off the purchase, and what incentivised them to do so? I did write to them to ask about their reasons for this apparent degradation in tram technology, but needless to say they didn't even reply. :roll:

Your argument against the M5000s isn't exactly great. They're more reliable than the T68s, are lighter so won't pound the track as bad (thus saving money in the long run) and since they're a full tram design they won't rust when they come in contact with the grit salt used in winter on the roads. I'm not saying they're perfect but you're making out as if they're the worst things on rails.

 

[northwichcat]

are lighter so won't pound the track as bad (thus saving money in the long run)

Well fitting a lower density of seats helps make them lighter.

 

[Emyr]

Except then you have more space for heavy passengers.

 

[edwin_m]

Indeed. A vehicle designed for more standing passengers needs to be stronger because there can be more people on the same area of floor. I believe this is why buses designed for the UK market aren't used on the Continent.

 

[Greybeard33]

Well Metrolink have lowered the line speeds in places. Prior to the T68 withdrawal some of the speed restriction signs said 'M5000 only'

The conversion from block signalling to line of sight operation also requires permanent speed restrictions in some areas, because the driver must be able to stop within the distance s/he can see ahead. This has not had much effect on the (mainly straight) Altrincham line, but the Bury line (not yet converted) is much more curvaceous.

 

[Bill Stanier]

I'm not saying they're perfect but you're making out as if they're the worst things on rails.

I think you need to read my posts again. I'm not 'making out' anything. I am stating that the new trams ride in a completely unacceptable manner off street, whereas the old trams didn't, and I'm asking why Metrolink think that's OK.

If you're going to be accusative, at least be accurate, please.

 

[dggar]

I think you need to read my posts again. I'm not 'making out' anything. I am stating that the new trams ride in a completely unacceptable manner off street, whereas the old trams didn't, and I'm asking why Metrolink think that's OK.

If you're going to be accusative, at least be accurate, please.

I've travelled on the old trams between Prestwich and Bury and experienced the same exhilarating ride as can be found with the new trams.

 

[Bill Stanier]

I've travelled on the old trams between Prestwich and Bury and experienced the same exhilarating ride as can be found with the new trams.

What prompted my comments was a journey Altrincham to Bury on new trams, and back on old ones. Chalk and cheese as far as ride was concerned on the off street sections. On the outward journey (when we discussed the appalling ride between ourselves while observing the driver almost being flung out of his seat) regular passengers were complaining to us how badly these new trams ride compared to the ones they were replacing.

Furthermore on arrival at Altrincham we asked the driver about it, and he agreed the old trams do ride far better than the new. He put it down to the old ones having more sophisticated (air) suspension - I don't know if that's true.

 

[edwin_m]

The old trams did indeed have air suspension and the new ones don't. However be a bit careful about comparing rides in opposite directions because one track is significantly newer than the other over most of the Altrincham line (sorry don't recall which).

I don't ride it often enough for a systematic observation but I do get the impression some M5000s ride much better than others so these may have had the new wheel profile (which was being talked about a couple of years ago) and the extra springs (which is a new one to me).

Looking out of one end of the tram you can see how the shininess of the rails varies in phase with the oscillation of the tram, which implies that the tram is imparting a cyclic sidewear pattern onto the track, which then increases the tendency of the tram to oscillate and worsen the cyclic sidewear. So even a tram with perfect wheel profiles and suspension will oscillate to some extent, until (if this is possible) the wear pattern is ground out, or the rail is replaced.

If the T68s were indeed the source of the problem, they may have been holding off remedial measures until the T68s were out of the way, otherwise money spent on track, and possibly also on M5000 mods, might have been wasted.

 

[DynamicSpirit]

Looking out of one end of the tram you can see how the shininess of the rails varies in phase with the oscillation of the tram, which implies that the tram is imparting a cyclic sidewear pattern onto the track, which then increases the tendency of the tram to oscillate and worsen the cyclic sidewear. So even a tram with perfect wheel profiles and suspension will oscillate to some extent, until (if this is possible) the wear pattern is ground out, or the rail is replaced.

If the T68s were indeed the source of the problem, they may have been holding off remedial measures until the T68s were out of the way, otherwise money spent on track, and possibly also on M5000 mods, might have been wasted.

So - if I've understood you correctly - are you suggesting that the T68's may have damaged the track, and that could be (partially) what's causing the poor ride quality on the newer trams? If so, is that speculation or based on some other knowledge?
--- old post above --- --- new post below ---

The conversion from block signalling to line of sight operation also requires permanent speed restrictions in some areas, because the driver must be able to stop within the distance s/he can see ahead. This has not had much effect on the (mainly straight) Altrincham line, but the Bury line (not yet converted) is much more curvaceous.

Out of interest, why would Metrolink change the signalling system in that way if it's going to lead to slower journeys? Is it a cost/savings measure or is there some other benefit?

 

[Manchester77]

Out of interest, why would Metrolink change the signalling system in that way if it's going to lead to slower journeys? Is it a cost/savings measure or is there some other benefit?

TMS is line of sight signalling which allows PIDs to be operated and real time information for a smartphone app. On SCC it's been stated that special techniques are being employed on parts of the bury line (such as the tunnels and sweeping curves) to ensure speeds can be kept high but drivers see where the tram is, these include displays for drivers at tunnel entrances. Having TMS operating to entire network is beneficial since you don't have to pass trams from one system to another.

 

[Greybeard33]

The old trams did indeed have air suspension and the new ones don't. However be a bit careful about comparing rides in opposite directions because one track is significantly newer than the other over most of the Altrincham line (sorry don't recall which).

There has been a 30mph TSR (M5000 only) inbound between Dane Road and Stretford for some considerable time, due to track condition.

I don't ride it often enough for a systematic observation but I do get the impression some M5000s ride much better than others so these may have had the new wheel profile (which was being talked about a couple of years ago) and the extra springs (which is a new one to me).

Some T68s also used to exhibit violent hunting at speed, whereas others were very smooth on the same stretch of track. I suspect it varies with wheel wear.

Looking out of one end of the tram you can see how the shininess of the rails varies in phase with the oscillation of the tram, which implies that the tram is imparting a cyclic sidewear pattern onto the track, which then increases the tendency of the tram to oscillate and worsen the cyclic sidewear. So even a tram with perfect wheel profiles and suspension will oscillate to some extent, until (if this is possible) the wear pattern is ground out, or the rail is replaced.

I recall reading somewhere that rail life can be extended by shifting one rail longitudinally relative to the other, so that the wear patterns no longer match.

If the T68s were indeed the source of the problem, they may have been holding off remedial measures until the T68s were out of the way, otherwise money spent on track, and possibly also on M5000 mods, might have been wasted.

The T68 was a much heavier vehicle, so presumably wore the track faster, other things being equal. All articulated trams are inherently prone to hunting and I gather that the suspension stiffness and wheel profile have to be a compromise between the requirements for on-street running and those for high speeds on reserved track.

 

[northwichcat]

The old trams did indeed have air suspension and the new ones don't. However be a bit careful about comparing rides in opposite directions because one track is significantly newer than the other over most of the Altrincham line (sorry don't recall which).

I don't think that is really the case. In 2007? Metrolink replaced large sections of track on the Altrincham line between Timperley and Cornbrook, some of the better sections of old track remained but there's certainly a mixture of new and old in both directions. (Timperley-Altrincham is only old track.)
--- old post above --- --- new post below ---

the T68's may have damaged the track, and that could be (partially) what's causing the poor ride quality on the newer trams? If so, is that speculation or based on some other knowledge?

From what I understand it's a bit like the left hand lane of a Motorway. The high number of lorries using it wears the road out more quickly in certain places, then if you drive a different vehicle like a car or van over it then it doesn't feel that smooth.

With Metrolink it's likely if the M5000s had been running services since 1992 and new T68s had been introduced then they would have been blaming M5000s for any poor ride quality.

 

[edwin_m]

So - if I've understood you correctly - are you suggesting that the T68's may have damaged the track, and that could be (partially) what's causing the poor ride quality on the newer trams? If so, is that speculation or based on some other knowledge?

I believe that was being suggested when they got Manchester Metropolitan University in to look at the problem (the team moved to Huddersfield sometime during the process). But I don't recall the source and Google doesn't find anything relevant.

Out of interest, why would Metrolink change the signalling system in that way if it's going to lead to slower journeys? Is it a cost/savings measure or is there some other benefit?

Metrolink will be (and most of it now is) operate on line of sight which allows trams to run more frequently. For example the previous signalling would not have allowed the necessary number of trams on the section through Cornbrook. It also gets rid of existing signalling which was potentially a source of unreliability and would have cost a lot to replace like-for-like.

 

[Rapidash]

Just had a week of using 'em. Can't say I noticed many issues from Salford Quays other than that corner coming into Exchange Quay.

Bloody cheap to use, arnt they? £15 for the week is a damn good.

 

[radamfi]

Just had a week of using 'em. Can't say I noticed many issues from Salford Quays other than that corner coming into Exchange Quay.

Bloody cheap to use, arnt they? £15 for the week is a damn good.

The poor ride quality issues are mostly on the higher speed lines which have been converted from old railway lines. The line from Salford Quays and Eccles is particularly slow because there are so many tight bends. Fares on that line are lower than on other Metrolink lines. You can go the whole way from Eccles to Piccadilly for £15 a week, but from Piccadilly to Stretford it is £16 a week.

 

[northwichcat]

The poor ride quality issues are mostly on the higher speed lines which have been converted from old railway lines. The line from Salford Quays and Eccles is particularly slow because there are so many tight bends. Fares on that line are lower than on other Metrolink lines. You can go the whole way from Eccles to Piccadilly for £15 a week, but from Piccadilly to Stretford it is £16 a week.

Eccles-Manchester is slower on the tram than on the bus.

 

[WatcherZero]

Yeah though the bus goes as the crow flies straight to the city centre while the tram serves the length of the quays.