West Midlands Metro CAF Tram Cracks. More problems 13 Nov 2021

[TheSignalEngineer]

It seems that not only the 'big railway' has rolling stock problems. Reports coming through from the West Midlands Metro today state

 

“We are sorry that there will be no Metro services from 11 June until further notice.

We have been informed by the vehicle manufacturer that they have identified a fault which is affecting some of our trams.

As a precautionary measure, we have taken the decision to remove all 21 trams from service until all trams have been inspected.

We are working alongside the manufacturer, CAF, to restore services as quickly as possible.”

 

 

Edited November 12, 2021 by TheSignalEngineer
Title updated. More cracks 13 Nov 2021

[TheSignalEngineer]

British Trams Online website reported a quote from the  Managing Director of Midland Metro Ltd, Steve McAleavy that appeared in the Wolverhampton Express and Star. This is part of the comment:-

 

 "..... We have a fleet of CAF Urbos 3 trams and the manufacturer of those trams in a maintenance inspection identified some cracks in the underframe structure at either end of the tram. CAF were unable to assure us that the cracks did not represent a safety issue if we continued to operate. Our first priority is to ensure the safety of our customers and our colleagues and therefore the right thing to do was to remove the trams from service whilst inspections are carried out. The inspections have already commenced and will continue throughout the weekend and will be completed by Monday. Once the inspections have been completed we will be able to make a decision about when we can resume service.  ....."

[Enterprisingwestern]

 

Well, if they insist on buying Spanish rubbish!

 

Mike.

[great central]

58 minutes ago, Enterprisingwestern said:

 

Well, if they insist on buying Spanish rubbish!

 

Mike.

 

Bit of a risky statement from someone who insists on living there?

[Robert Shrives]

Sadly the alternative version of CAF  does seem to ring true - probably unjustified but recent developments and the hindsight police  will likely show that a given chassis has a working stress life if built to a price with no redundancy in material used. By beefing up and thus weight and power required to move you can probably get an infinite stress life - look at numbers of steam locos that had cracked frames it is hardly a new thing.   In the trams I wonder if original construction expected to have a tonne of batteries added in the end vehicles?   Slightly off topic but with the GWR 800s perhaps hanging bigger fuel tanks and engines might enter the same life limiting stress phase . IIRC at least one HST had cab almost dropping off due to frame cracks forward of the bogie centres.  Who remembers the BOAC Comet crashes and following investigations - stress cracks around altered windows saw top of planes break away ...    

[Enterprisingwestern]

1 hour ago, great central said:

 

Bit of a risky statement from someone who insists on living there?

 

We all make mistakes!

 

Mike.

[jonhall]

2 hours ago, Enterprisingwestern said:

 

Well, if they insist on buying Spanish rubbish!

 

Mike.

 

They still represent an improvement on the original Ansaldo Breda trams!

 

Jon

[AY Mod]

3 hours ago, Enterprisingwestern said:

 

Well, if they insist on buying Spanish rubbish!

 

It sounds like you're in training to jump in on local Facebook groups here but the yams are incapable of determining the country of origin; it's all just foreign rubbish to them.

 

They're just bitter they can't get to Torremelinos this year and will have to drive to Barmouth in their forrin cars and stay in a Chinese-made tent. 

[Wheatley]

Northern haven't hung any additional batteries or engines off their 195/331s, in most cases they haven't the weight of any passengers added either for most of the last 14 months, and they still cracked. 

[wombatofludham]

6 hours ago, AY Mod said:

 

 

They're just bitter they can't get to Torremelinos this year and will have to drive to Barmouth in their forrin cars and stay in a Chinese-made tent. 

 

[TheSignalEngineer]

9 hours ago, jonhall said:

 

They still represent an improvement on the original Ansaldo Breda trams!

 

Jon

I was working on the immunisation of the heavy rail signalling against the electrical interference from the original trams. During our monitoring of test running it appeared that several had different electrical signatures when running over the same section of line. From conversations with the Metro people it appeared that every Ansaldo Breda T-69 tram was put together slightly differently depending who on the production line worked on it. Most were not watertight, rain getting into the electrics on some of them in the early days

[TheSignalEngineer]

10 hours ago, jonhall said:

 

They still represent an improvement on the original Ansaldo Breda trams!

 

Jon

AnsaldoBreda is now Hitachi Rail Italy, and they built the Class 802 units.

[Busmansholiday]

Don't forget that Sheffield's Spanish built Stadler tram-trains have had their fair share of problems.

[cheesysmith]

Most of the tram  train problems are of the road vehicle interface.

[Robert Shrives]

Hi, a friend in fleet procurement and testing  did advise the Ansaldo trams were 16 fleets with one tram in each fleet. As they seem to have been 16 hand built by apprentices with on roof equipment locations slightly differing it was not possible to make hybrids out of any crash pairs. Certainly entertaining to operate the service.  

 

Slightly bad timing as as Broad street section prepares to go live the route will be  broken at Short sighted junction between upper and lower Bull street as part of the inner city  changes for the Digbeth (HS2) works but  as ever reference to HS2 is minimised !   If fleet had failed 4 months from now it would have reduce impact with a shorter network. 

[TheSignalEngineer]

Reports today that more cracks have been found in the CAF trams and services are being suspended. Forecast is at least four weeks to do the remedial work.

.

https://www.bbc.co.uk/news/uk-england-birmingham-59261154

 

[Pandora]

An update

https://www.bbc.co.uk/news/uk-england-birmingham-57452252

 

The update (link above) is still too vague on the nature of the problem, ,  are the cracks on the plain metal of the under-frames,  are they welds which are breaking , or cracks where holes have been drilled to attach components, or something else?

[Robert Shrives]

Well it seems serious enough as the mayor is banging his tin drum "demanding answers." Quotes of heads will roll do nothing for a serious information release as nodoubt lawyers are rubbing hands with glee - well half of them anyway.  Hanging batteries on the original fleet was seen as a problem in June, but reports are cracks effecting the newer supplied complete with bunny cells. ( Duracells!)  However the little fact that the in town section from Upper Bull st via Short sighted junction to the curve before "Grand Central where? Oh you mean New St station" tram stop has been relaid with Kato style unitrack after the original hand lay (Pcb?) was found to be defective/ poor build with rails made of cheesy strings then CAF will have some play of damage to the trams from track faults  not just the limited design scope of the scrap they have glued together - cereal packet quality kits of old spring to mind.

I can see electric string will be erected on the previous battery only sections  and the batteries on evilbay to fund the party for when the Mayor swings from a nearby traction pole...      However the good news is that at least the crews will not suffer the vomit, pXXs and abuse from "German/European/ Christmas/ Winterval "p**s lager and cheap Chinese tat market goers/ louts. Sadly the drivers of the Green bus replacement effort and trains with ticket acceptance on the BHM - WVH corridor will just get it instead...    On Sunday the multiple piles of vomit by the tram stops near Victoria square tell the truth, a colleague almost had a paddle on the way to work, vocally unimpressed when in the office!  

[cctransuk]

4 minutes ago, Robert Shrives said:

Well it seems serious enough as the mayor is banging his tin drum "demanding answers." Quotes of heads will roll do nothing for a serious information release as nodoubt lawyers are rubbing hands with glee - well half of them anyway.  Hanging batteries on the original fleet was seen as a problem in June, but reports are cracks effecting the newer supplied complete with bunny cells. ( Duracells!)  However the little fact that the in town section from Upper Bull st via Short sighted junction to the curve before "Grand Central where? Oh you mean New St station" tram stop has been relaid with Kato style unitrack after the original hand lay (Pcb?) was found to be defective/ poor build with rails made of cheesy strings then CAF will have some play of damage to the trams from track faults  not just the limited design scope of the scrap they have glued together - cereal packet quality kits of old spring to mind.

I can see electric string will be erected on the previous battery only sections  and the batteries on evilbay to fund the party for when the Mayor swings from a nearby traction pole...      However the good news is that at least the crews will not suffer the vomit, pXXs and abuse from "German/European/ Christmas/ Winterval "p**s lager and cheap Chinese tat market goers/ louts. Sadly the drivers of the Green bus replacement effort and trains with ticket acceptance on the BHM - WVH corridor will just get it instead...    On Sunday the multiple piles of vomit by the tram stops near Victoria square tell the truth, a colleague almost had a paddle on the way to work, vocally unimpressed when in the office!  

 

Your posting would have been much more understandable - and effective - without all the crude irony.

 

CJI.

[jim.snowdon]

On 14/11/2021 at 04:02, Pandora said:

An update

https://www.bbc.co.uk/news/uk-england-birmingham-57452252

 

The update (link above) is still too vague on the nature of the problem, ,  are the cracks on the plain metal of the under-frames,  are they welds which are breaking , or cracks where holes have been drilled to attach components, or something else?

Some may remember that when Siemens introduced their Combino trams to Amsterdam, they ran into problems with cracking in the bodyshells. The structurally similar Alstom Citadis trams built for Den Haag didn't suffer quite the same fate, but were prone to derailing on tracks that incorporated both horizontal and vertical curvature. The common factor is that they are long, multipart articulated trams, and the problem is one of torsional stiffness. If you combine a tight horizontal curve with a significant change of gradient, the front end of the tram is going up (or down) hill at something approaching right angles to the rear of the tram, which is still standing upright. The effect is to put a considerable twist in the tram from one end to the other, resulting in torsional strain on both the individual bodyshells and the stabilising linkages between them. The resulting cyclical strain reversals eventually result in fatigue cracking. With the bodyshells being pierced on both sides by window and door openings, the corner joints between the window/door pillars and the floor/roof are particularly liable to failure. So, are the articulation joints. Central Birmingham is not exactly level, which makes the geometry of the track between Paradise Circus and Snow Hill decidedly tortuous. When it comes to sorting out who is liable, the contract specification will undoubtedly come under very close scrutiny. If that failed to appreciate the problem, CAF become simply the victim and the consulting engineers have some explaining to do.

 

[Pandora]

An interesting post, Jim.snowdon, what was the long-term fix for the Combinos?  Did they redesign the linkages?  such as  changing the specification of  the torsion link system ( anti-roll bars) to something softer and more flexible than the original parts?

Edited November 17, 2021 by Pandora

[seraphim]

I believe the Combino issue was that the integrity of the bodyshell could not be guaranteed in some accident scenarios. I think the bodyshell was beefed up in some areas, but don't have any detail on that. The problem with that type of fix is that it then pushes the problem elsewhere in the bodyshell - maybe to somewhere which can't be seen. I understand the similar Urbos3 fleet in Sydney has also been withdrawn from traffic. It will be interesting to see what effect there is on the Edinburgh Urbos2 fleet.

 

The suggestion from Robert Shrives that this is linked to the battery mod is unfounded garbage. The whole point of the Urbos3 fleet was to allow battery retrofit, and the work was carried out by CAF themselves.

[Busmansholiday]

Some interesting reading, and pictures of the problems in Australia if you search, ie;

https://www.google.com/amp/s/amp.abc.net.au/article/100600216

 

https://www.google.com/amp/s/amp.smh.com.au/national/nsw/cracks-seen-opening-and-closing-on-inner-west-trams-20211109-p597hm.html

 

https://www.news.com.au/technology/innovation/design/city-with-same-trams-as-sydney-also-shuts-down-its-light-rail-network-due-to-cracks/news-story/7be63aa44a9318e63f153928b3f09c4d

 

And an interesting explanation in the last link;

It’s a particularly poor design. They can be fixed but you’re starting from a poor point,” he told news.com.au.

Compromises were made with the designs of the vehicle, Mr Galloway said, so the trams could be made with flat floors and so be fully accessible.

A lower floor meant the wheel sets, called bogies, were housed in boxes with a restricted space that didn’t leave room for them to swivel. In turn, that may have led to more stress on the wheels which was increased when the trams travelled around several tight corners on the L1 line.

[jim.snowdon]

3 hours ago, Busmansholiday said:

Some interesting reading, and pictures of the problems in Australia if you search, ie;

https://www.google.com/amp/s/amp.abc.net.au/article/100600216

 

https://www.google.com/amp/s/amp.smh.com.au/national/nsw/cracks-seen-opening-and-closing-on-inner-west-trams-20211109-p597hm.html

 

https://www.news.com.au/technology/innovation/design/city-with-same-trams-as-sydney-also-shuts-down-its-light-rail-network-due-to-cracks/news-story/7be63aa44a9318e63f153928b3f09c4d

 

And an interesting explanation in the last link;

It’s a particularly poor design. They can be fixed but you’re starting from a poor point,” he told news.com.au.

Compromises were made with the designs of the vehicle, Mr Galloway said, so the trams could be made with flat floors and so be fully accessible.

A lower floor meant the wheel sets, called bogies, were housed in boxes with a restricted space that didn’t leave room for them to swivel. In turn, that may have led to more stress on the wheels which was increased when the trams travelled around several tight corners on the L1 line.

Mr Galloway doesn't deliver the most authoritative of explanations. These multi-section trams are essentially several four wheel cars with suspended sections between them. They don't have bogies, and the wheels do not swivel relative to the car body.

 

6 hours ago, seraphim said:

I believe the Combino issue was that the integrity of the bodyshell could not be guaranteed in some accident scenarios. I think the bodyshell was beefed up in some areas, but don't have any detail on that. The problem with that type of fix is that it then pushes the problem elsewhere in the bodyshell - maybe to somewhere which can't be seen. I understand the similar Urbos3 fleet in Sydney has also been withdrawn from traffic. It will be interesting to see what effect there is on the Edinburgh Urbos2 fleet.

 

The suggestion from Robert Shrives that this is linked to the battery mod is unfounded garbage. The whole point of the Urbos3 fleet was to allow battery retrofit, and the work was carried out by CAF themselves.

That wasn't my understanding of the issue at the time (when I was actively involved as a tramway engineer). The bodies will have been designed to the BoStrab standards, which are pretty well universally accepted in mainland Europe, and any failure to meet the collision loading criteria would have resulted in their not achieving homologation (ie approval for use in Europe). What those standards had not really woken up to, at least when I knew about them, was the issues of body twist for very long multi-section trams. They were conceived when articulated tram were generally two sections, carried on three bogies.