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Liverpool Metro Area 'Scouse Scrapers for both sides of the Mersey



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Old March 20th, 2011, 02:33 PM   #81
Martin S
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With the right rolling stock a newly morphed metro can then extend in to Wirral and Liverpool Waters. DLR type of roling stock is the first and vital move for Merseyrail and the city as a whole.
This is a more technical issue and I have given this one some thought as, on first sight at least, there is some merit to it.

It is often surprising how trains that perform relatively similar functions are so different. So, for example, DLR trains are very different from London Underground tube stock, Manchester Metrolink trams are very different from Croydon trams and Merseyrail trains are different from London Underground sub-surface stock.

Some of it is obviously down to styling and the structure gauges (nobody is going to recommend Class 507s for the Glasgow Subway without a fair amount of 'jiggery-pokery'). However there are some more subtle issues.

If you want to decide on what the best rolling stock for a particular rail system is, you need to have some idea of what the purpose of that rail system is. Merseyrail has some 70 route miles of mainly suburban and outer suburban railway of which only 6.5 miles could be described as an underground metro system. Consequently, you are going to select rolling stock that is best suited to suburban type operations.

That involves compromises. The Class 507/508 stock is not best suited for running in the tight radius Merseyrail underground tunnels - you only have to consider the problems there have been over the years with replacing rails and wheelsets due to excessive wear. That is mainly because the rigid wheelbase of the train bogies prevents the wheels from following the curve of the rails - they will always be at a small angle, which means that the wheel is trying to climb over the railhead. In extreme circumstances, that can lead to derailment, more often it just means more frequent replacement of wheels and rails.

One solution to that problem is the use of rail flange greasers - but these require regular maintenance and replenishment - the long term solution is the use of trains with special suspension systems that allow the wheels to follow the curves more accurately (that was the initial intention when the tunnels were built but, for some reason, was not implemented). Hopefully, when the rolling stock is replaced in 2013 or whenever, that issue will be resolved.

Use of DLR trains would not necessarily resolve the problem. As far as I am aware, they do not have the radial wheelsets that would be required. They are articulated - but that is to resolve a completely different problem.

DLR was initially conceived as an above ground railway, mainly on viaducts. In more recent years it has evolved into a partially underground system but the trains have remained largely the same.

Articulation of the vehicle bodies was required to enable trains to negotiate tight curves. Reducing the rigid length of the vehicle (14m as opposed to the 20m of a Merseyrail unit) means that the 'centre and end throws' (the overhangs formed by a straight vehicle trying to go round a curve) are reduced and the train does not have so wide a 'swept envelope' - an important consideration when trains need to go round buildings and for that reason trams are often articulated.

However, articulation doesn't exempt you from the laws of physics. If you go round a bend at speed, you will experience a high centrifugal force, which is uncomfortable for passengers and can derail the train, so for that reason DLR goes at much lower speeds than Merseyrail.

Using DLR vehicles on Merseyrail would probably cause far more problems than it would solve. Let's forget trivial details such as the different current collection methods, the different platform stepping distances and the fact that DLR are automatic trains (which would require complete resignalling of Merseyrail if it were allowed at all).

DLR units are primarily metro trains. They are designed to carry large numbers of passengers over relatively short distances. A Merseyrail train of comparable length to a DLR train would have some 50% more seats. That is not just the seating configuration, it is the fact that the individual vehicles are much shorter and so much space in the train length is given over to the connections between vehicles, more frequent and wider doors and the articulation. Also, the trains are significantly narrower than Class 507/508s.

John has suggested that the use of tight curving DLR trains would make his scheme for a metro system for Liverpool easier to achieve. That would be true if he was planning a system that was mainly above ground and had to snake around buildings - but most of his proposed system would be underground - and underground you can make curve radii as large as you like. In fact, if you think about it, a tunnel linking two straight lines at an angle would be shorter if the radius was increased, so construction costs would be lower and trains could run at higher speeds. The complexity of the junction (i.e. whether you would need a flat or grade separated arrangement) would not be affected.

So, using DLR trains would not be the answer but there may well be a case for using lighter units than we have at present. One reason that the suburban type trains used on our system are so heavy is that they are designed to protect passengers in the event of a collision with other heavy rail trains. With the system almost fully segregated from the main rail network, lighter rail units might be acceptable (although the speed of running must also be a factor). Lighter vehicles not only need less energy to accelerate or climb gradients but reduce damage to the track. I suppose that the aluminium bodied 507/508s are on the lighter side of 'heavy rail' but there should be scope for improvement.

Of course, when it comes to rolling stock replacement, it will always be cheaper to buy vehicles of similar specification to ones used elsewhere (due to the reduced cost of a long production run), rather than order bespoke vehicles specifically tailored to Merseyrail. It all boils down to economics in the end.
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Old March 20th, 2011, 06:09 PM   #82
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Dragging the thread back somewhat to reality rather than fantasy and arguments...

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Merseyside Passenger Transport Executive ("MPTE") is currently considering its options around the replacement of its current fleet of Class 507/508 EMU Rolling Stock. Should it decide to replace the rolling stock following conclusion of its business case process it would be seeking to award a contract for the design, manufacture and supply of in the region of 150-250 third rail electric (750v) vehicles together with spare parts. In connection with the purchase of new vehicles MPTE is also interested to receive proposals relating to the final assembly, testing and commissioning of such vehicles specifically for operation on the Merseyrail Electrics network and for the provision of maintenance facilities appropriate to such vehicles, as well as funding for the purchase of such vehicles by MPTE and the provision of any infrastructure enhancements which would be necessary to facilitate the operation of the new Rolling Stock on the Merseyrail Electrics network ("the Project").
Source: http://www.publictenders.net/tender/97747
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Old March 20th, 2011, 07:40 PM   #83
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Rather wooly of what they actually want. We don't know what they want, but many of us know what they need.
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Old March 20th, 2011, 09:52 PM   #84
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Originally Posted by Mostly Lurking View Post
Dragging the thread back somewhat to reality rather than fantasy and arguments...



Source: http://www.publictenders.net/tender/97747
I note that it's specifically mentioning third rail, with no mention of them being dual voltage. I thought that was an going to be part of the new trains so that they could keep their options open going forward.
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Old March 20th, 2011, 10:05 PM   #85
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I note that it's specifically mentioning third rail, with no mention of them being dual voltage. I thought that was an going to be part of the new trains so that they could keep their options open going forward.
Almost all new third rail units can be run on overhead with the simple addition of a pantograph and equipment.
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Old March 20th, 2011, 10:07 PM   #86
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Almost all new third rail units can be run on overhead with the simple addition of a pantograph and equipment.
How simple is that?
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Old March 20th, 2011, 10:09 PM   #87
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Yur personality disorder is clear. You never stick to a topic, take matters to persoanl levels and take sides with known head-the-balls. Get is sorted kidda.
Oh yawn, the irony is incredible.


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Almost all new third rail units can be run on overhead with the simple addition of a pantograph and equipment.
Yeah, I heard it was standard these days. That said, only major expansions may possibly see this. The relatively small extensions to Headbolt Lane & Woodchurch will probably just be third rail and it'll be years before they look beyond that, I reckon.
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Old March 20th, 2011, 10:31 PM   #88
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How simple is that?
Very.

There is no point building units with a pantograph if it won't be used for many years as there are maintenance (and therefore training) costs associated - the same reason why some AC units (and Eurostar sets) have had their third rail shoes removed even though they are dual voltage.

Just about all DC units built in the last 10-15 years from the main manufacturers can be converted to dual voltage (or AC only) easily.
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Old March 21st, 2011, 12:50 AM   #89
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Ah, I didn't realise it was a simple job. I'll step down now
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Old March 21st, 2011, 09:32 PM   #90
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Originally Posted by Mostly Lurking View Post
Dragging the thread back somewhat to reality rather than fantasy and arguments...

Quote:
Merseyside Passenger Transport Executive ("MPTE") is currently considering its options around the replacement of its current fleet of Class 507/508 EMU Rolling Stock. Should it decide to replace the rolling stock following conclusion of its business case process it would be seeking to award a contract for the design, manufacture and supply of in the region of 150-250 third rail electric (750v) vehicles together with spare parts. In connection with the purchase of new vehicles MPTE is also interested to receive proposals relating to the final assembly, testing and commissioning of such vehicles specifically for operation on the Merseyrail Electrics network and for the provision of maintenance facilities appropriate to such vehicles, as well as funding for the purchase of such vehicles by MPTE and the provision of any infrastructure enhancements which would be necessary to facilitate the operation of the new Rolling Stock on the Merseyrail Electrics network ("the Project").
Source: http://www.publictenders.net/tender/97747
According to Wikipedia, there are 32 trainsets of Class 507 and 27 trainsets of Class 508 working on Merseyrail at present. As each trainset is 3 vehicles, that gives 177 vehicles.

Be interesting to know how they account for the wide stated range in the numbers of new vehicles. How could present passenger volumes be carried in 150 vehicles without worsening overcrowding? Then how could you justify 250vehicles without going for a smaller vehicle size (John's dream come true?) or having some in the garage for future extensions?
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Old March 22nd, 2011, 03:03 PM   #91
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Merseyrail seeks expression of interest for companies to build new fleet of trains

THE much awaited replacement of Merseyrail’s train fleet has taken a major step forward with manufacturers being asked to come forward with expressions of interest.

Transport authority Merseytravel wants companies to give an idea of how much a new fleet will cost.

Manufacturers have been informed of the move through what is called a Periodic Indicative Notice in the Official Journal of the European Union.

Merseyrail was due to replace its existing 57-strong fleet of trains by 2015, when the contract for its current rolling stock with train leasing company Angel Trains runs out.

Earlier this month the Daily Post reported how Merseytravel, which oversees the Merseyrail franchise, was in talks with Angel Trains to extend the lease to 2017.

It is estimated that the process of seeking expressions of interest, tendering for the work, and having trains built will take around five years.

In the meantime the current fleet will be modified to make sure it remains reliable.

Last night Merseytravel chairman Cllr Mark Dowd said: “This is the first step towards replacing the rolling stock which will help us to ensure Merseyrail’s position as one of the best performing rail companies in the country.”

The news will be welcomed by commuters using the popular Merseyrail network.

Some of the biggest names in train manufacturing like Bombardier, Siemens, and Alstom are expected to throw their hat in the ring. The closing date for expressions of interest is April 30.

The notice states: “Merseyside Passenger Transport Executive is currently considering its options around the replacement of its current fleet of Class 507/508 EMU Rolling Stock should it decide to replace the rolling stock following conclusion of its business case process.”

Neil Scales, chief executive of Merseytravel, added: “This is a precursor to inviting tenders and allows manufacturers to express an interest in a contract to replace the rolling stock. Meanwhile we are undertaking a programme of modifications.”
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Old March 22nd, 2011, 03:20 PM   #92
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“Merseyside Passenger Transport Executive is currently considering its options around the replacement of its current fleet of Class 507/508 EMU Rolling Stock should it decide to replace the rolling stock following conclusion of its business case process.”

What is the " business case"?

Siemens make some impressive light-rail trains.
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Old March 22nd, 2011, 09:08 PM   #93
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i would assume the amount of cash they have to spend to pay for the new stock!
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Old March 23rd, 2011, 01:24 AM   #94
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i would assume the amount of cash they have to spend to pay for the new stock!
Which might mean cheaper light-rail.
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Old March 23rd, 2011, 09:32 PM   #95
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From what I know about rolling stock procurement, the trains would not be owned by Merseyrail but leased from a rolling stock leasing company (ROSCO), which in this case would be (I think), Angel Trains.

Merseyrail would specify them and draw up a business case for their use but they would be funded by the banks.

The business case would look into the cost of constructing, operating and maintaining the trains, the possibility of deferring this cost by life extending the existing units or, maybe, leasing trains displaced from other networks.

Light rail trains may well be cheaper to buy but may not have the capacity, speed range or design life of a heavier train. They would almost certainly do less damage to the track, especially in the curved tunnel sections but then the track might need to be maintained to a higher standard to ensure good ride quality. I'm sure it will be a complicated process.

I think I am right in saying that these new trains will be the first designed specifically to run on the Merseyrail network since the 502/503 units of the 1930s/1950s.
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Old March 23rd, 2011, 10:21 PM   #96
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Fantastic news from the budget that the northern rail hub is progressing. If I'm not mistaken I think it's confirming money we had already heard was going to be invested, but it's still great news in the current environment to see the money committed - a major gain to Liverpool's connectivity and inward investment prospects. Shorter journey times to Manchester and Leeds equals more jobs, which is what we need.
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Old March 23rd, 2011, 10:25 PM   #97
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Pretty much spot on Martin about the process. It has been rumoured in the past though that Merseyrail would buy outright, but I don't know if that would happen.
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Old March 23rd, 2011, 10:27 PM   #98
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Fantastic news from the budget that the northern rail hub is progressing. If I'm not mistaken I think it's confirming money we had already heard was going to be invested, but it's still great news in the current environment to see the money committed - a major gain to Liverpool's connectivity and inward investment prospects. Shorter journey times to Manchester and Leeds equals more jobs, which is what we need.
If I understand it correctly design_man, it is actually better than that. It is the DfT directly funding a part of it instead of waiting for the next Network Rail control period.
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Old March 24th, 2011, 01:40 AM   #99
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I think I am right in saying that these new trains will be the first designed specifically to run on the Merseyrail network since the 502/503 units of the 1930s/1950s.
Which were initially meant for Poland not Merseyside, so I believe. WW2 got in the way.

Last edited by Romania1; March 24th, 2011 at 01:05 PM.
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Old March 24th, 2011, 12:43 PM   #100
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If I understand it correctly design_man, it is actually better than that. It is the DfT directly funding a part of it instead of waiting for the next Network Rail control period.
That sounds even better! I just want them to get started on this, it's been studied and looked at for so long and it's frustrating that they haven't started it.
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