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Post by mrjrt on Nov 27, 2012 15:20:03 GMT
In a discussion on another forum it occurred to me that the 5th car might not be the ideal way to go regarding extensions of the class 378s, and I thought I might trawl for some additional opinions here.
Basically, the problem I have with the 5th cars is that it's the limit of the Electrostar design...it doesn't scale up to 6 cars, so services will always have to be shorter than the old 2x3 car 313s were (or at least, could have been!).
If instead of the 3rd car they split the 4 car trains in half and built two new DMSOs, then you would get your 6 car train (abet not all walk-through). The problem with that is of course that the 4th car they added isn't a pantograph car, so would need to have major alterations as well to serve in that role.
The next step up from a 6 car train is obviously an 8 car train, which would all be fine, except as they are extending the trains to 5 cars, so the next step up jumps to 10 cars...which is a hell of a lot more work to get to than 8 cars would be (which is still an awful lot!).
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Post by thc on Nov 27, 2012 15:53:40 GMT
...and breathe! Always remember that "the best is the enemy of the good". The development of the London Overground concession and the Class 378s were always about maximising the potential afforded by limited circumstances; the move to a fifth car for the Class 378s is costed, affordable and entirely consistent with that approach. Why is everything always so overwrought in jrt world?  THC |
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Post by andypurk on Nov 27, 2012 16:07:51 GMT
In a discussion on another forum it occurred to me that the 5th car might not be the ideal way to go regarding extensions of the class 378s, and I thought I might trawl for some additional opinions here. Basically, the problem I have with the 5th cars is that it's the limit of the Electrostar design...it doesn't scale up to 6 cars, so services will always have to be shorter than the old 2x3 car 313s were (or at least, could have been!). Where do you get the information that the Electrostar design doesn't scale to more than 5 cars? Just because no existing unit in the Electrostar fleet isn't longer than that doesn't imply that there is any underlying reason why longer units are not possible. Even if there was some limit in unit length, there is no fundamental difference between having a six car train formed of 2 x three car half units rather than 1 x 6 car complete unit. After all the class 460s were formed in this way from 2 x four car half units, as are the 8 and 9 car Pendolinos (the 11 car Pendolinos are formed of three part units). Going beyond five car train lengths would probably lead to a rethink anyway, as so much more infrastructure work would be needed, including in depots and stabling sidings. |
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Post by trt on Nov 27, 2012 16:19:16 GMT
Where do you get the information that the Electrostar design doesn't scale to more than 5 cars? Yes, curious about that too. Is there some internal register which numbers the carriages and which overflows at 6? I'd be very interested in this aspect of industrial design. |
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class411
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Post by class411 on Nov 27, 2012 17:09:02 GMT
Where do you get the information that the Electrostar design doesn't scale to more than 5 cars? Yes, curious about that too. Is there some internal register which numbers the carriages and which overflows at 6? I'd be very interested in this aspect of industrial design. Unlikely. Any limit is normally a power of two. In any case, at least the announcement/indicator system scales farther than that because it will tell you which coach of a twelve coach train you are occupying. |
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Post by redbond on Nov 27, 2012 17:24:32 GMT
Electrostars can be a maximum of 12 cars. Even the 378s show up to 12 available spaces for DOO cameras, 6 on each screen, so I'd say 6 is the maximum carriages per unit, not 5, unless there's some specifications from Bombardier you've seen.
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metman
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Post by metman on Nov 27, 2012 17:46:01 GMT
There would need to be some major engineering work on the ELL at several stations if 6 cars are to be used. I think 5 cars is the limit for now (as has been mentioned). The trains on the SE lines are 5 cars aren't they of a similar design. I think the Capitalstars are a good design for inner London services and probably have a far better crush loading capacity than any previous stocks.
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Post by Deleted on Nov 27, 2012 20:01:10 GMT
I reckon a 5 car 378 can carry more people than a two 313 units in multiple. In 313s a fair amount of space is wasted by having larger than normal cabs and there would be two of these in the centre of a 313 formation unusable by passengers.
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Post by bicbasher on Nov 27, 2012 21:19:31 GMT
The four car 378's are already doing their job of squeezing more people on the ELL than the 377/455s on Southern using the same 4 car formations to London Bridge. (Southern do have 8 and 10 car formations in the peak as well)
A 5th car will enable even more people to squeeze onto already busy West Croydon services in the peak in-particular between Canada Water and Forest Hill which appears to be the busiest stretch of the ELL.
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Post by mrjrt on Nov 27, 2012 21:54:27 GMT
Where do you get the information that the Electrostar design doesn't scale to more than 5 cars? Just because no existing unit in the Electrostar fleet isn't longer than that doesn't imply that there is any underlying reason why longer units are not possible. Even if there was some limit in unit length, there is no fundamental difference between having a six car train formed of 2 x three car half units rather than 1 x 6 car complete unit. After all the class 460s were formed in this way from 2 x four car half units, as are the 8 and 9 car Pendolinos (the 11 car Pendolinos are formed of three part units). Going beyond five car train lengths would probably lead to a rethink anyway, as so much more infrastructure work would be needed, including in depots and stabling sidings. Sorry, yes, I did indeed mean a 5-car limit for a single trainset...I figured it was obvious by suggesting 2x3-car trains to reach 6-cars I've been told several times over multiple discussions that there is a maximum limit of 5 cars, and although it's Wikipedia, this is repeated there: "Formation 3, 4 or 5 cars per trainset"I'd thus imagine 12 cars as an upper limit can only be reached by 3 4-car trainsets. ...and I'm just thinking bigger picture here. The ELL might well need lots of infrastructure work to reach 6 cars...but the NLL sure as hell doesn't, as it used to run with them. Dalston Kingsland to Stratford probably would, but there's nothing too problematic there. |
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Post by bicbasher on Nov 28, 2012 0:19:05 GMT
...and I'm just thinking bigger picture here. The ELL might well need lots of infrastructure work to reach 6 cars And it's certain some stations won't get them at all on the core section. Canada Water, Rotherhithe and Wapping for example which will have to have SDO regardless if it's 5 or 6 car. |
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Post by mrjrt on Nov 28, 2012 0:28:41 GMT
And it's certain some stations won't get them at all on the core section. Canada Water, Rotherhithe and Wapping for example which will have to have SDO regardless if it's 5 or 6 car. Quite. Especially given the walk-through carriages it can't be that great a difference to have a set of carriage doors at both ends out of use rather than just the one (or half of them at both ends, obviously!) |
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Post by andypurk on Nov 28, 2012 9:48:38 GMT
Where do you get the information that the Electrostar design doesn't scale to more than 5 cars? Just because no existing unit in the Electrostar fleet isn't longer than that doesn't imply that there is any underlying reason why longer units are not possible. Even if there was some limit in unit length, there is no fundamental difference between having a six car train formed of 2 x three car half units rather than 1 x 6 car complete unit. After all the class 460s were formed in this way from 2 x four car half units, as are the 8 and 9 car Pendolinos (the 11 car Pendolinos are formed of three part units). Going beyond five car train lengths would probably lead to a rethink anyway, as so much more infrastructure work would be needed, including in depots and stabling sidings. Sorry, yes, I did indeed mean a 5-car limit for a single trainset...I figured it was obvious by suggesting 2x3-car trains to reach 6-cars I've been told several times over multiple discussions that there is a maximum limit of 5 cars, and although it's Wikipedia, this is repeated there: "Formation 3, 4 or 5 cars per trainset"That is just what the current formations per unit are, not what is theoretically possible. Or 4 x 3 car units as used to run on at least one of the Victoria - Brighton services each hour. All of the current lines will need some work to accommodate six car trains, as many of the platforms are now too short. Indeed, I don't think that the NLL ever ran 2 x class 313 and six car units were limited to the shorter class 501 formations when they ran to Broad Street. Most of the current platforms on the section between Camden Road and Gunnersbury are only five car length at most (i.e. less than the 120m needed for a six car unit) and Willesden Junction High Level was only lengthened to fit a five car unit. The least work would be needed on the DC lines, but even here some platforms are disused at the extremes needed for six car trains. But the DC lines are probably the route in least need of lengthened trains. |
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Post by mrjrt on Nov 28, 2012 13:42:13 GMT
That is just what the current formations per unit are, not what is theoretically possible. It was explained to me that the base Electrostar design can't handle multiple pantograph cars in a single trainset, and a single pantograph car and associated power buses can only handle up to 5 cars. Thinking about it, I can't think of anything other than tube EMUs and the class 390s that have more than 5 cars per trainset. All of the current lines will need some work to accommodate six car trains, as many of the platforms are now too short. Indeed, I don't think that the NLL ever ran 2 x class 313 and six car units were limited to the shorter class 501 formations when they ran to Broad Street. Most of the current platforms on the section between Camden Road and Gunnersbury are only five car length at most (i.e. less than the 120m needed for a six car unit) and Willesden Junction High Level was only lengthened to fit a five car unit. The least work would be needed on the DC lines, but even here some platforms are disused at the extremes needed for six car trains. But the DC lines are probably the route in least need of lengthened trains. Indeed, ironic that the shortest platforms (the ELL) need the most, and the longest (the DC lines) need the least  Fair points on the new build stuff like Willesden - but I feel the wider point stands - there's not going to be any heavy engineering required as was the case at Dalston Kingsland to get it to 4 cars...just reinstating disused lumps of platform and moving signals. |
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Post by Deleted on Nov 28, 2012 13:47:20 GMT
I don't think that the NLL ever ran 2 x class 313 There were some 6 Car Class 313 workings on the Euston - Watford service when the Class 313's were first introduced onto the NLL but they were very rare as the power supply was insufficient for 6 car trains with 4 power cars together with the lack of Class 313's for this service. ECS 6 car Class 313's did occasionally run over the DC lines but usually with one set unpowered. XF |
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Post by trt on Nov 28, 2012 13:49:37 GMT
It was explained to me that the base Electrostar design can't handle multiple pantograph cars in a single trainset Ah! So it's an issue with potential phase and voltage differences when transiting supply areas. Well that makes sense, then. The car limit is then down to how much current you can draw for the motor cars, and how much you can throw along the supply busses between units. |
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Post by Ben on Nov 28, 2012 14:38:18 GMT
4th rail the whole lot, ditch the 378s, and order a new batch to the S stock design. Standardisation at its best.
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Post by fleetline on Nov 28, 2012 15:06:21 GMT
Electrostars can be a maximum of 12 cars. Even the 378s show up to 12 available spaces for DOO cameras, 6 on each screen, so I'd say 6 is the maximum carriages per unit, not 5, unless there's some specifications from Bombardier you've seen. Not true, on YouTube there a video of a 23 car 375 moving. Southern run 16 ECS on the BML. 12 cars is the limit due to signalling reasons in service not the train. Hence why when NR looked into 16 cars on SWT and it would have costed £1bn. Signalling problem is linked into the TPWS on units. As for six car 378, its possible but it was the cost of re-writing the software that was considered too expensive. Five car 376 software would be basis of the five car 378. Doing a new six car would require new safety case based in software at cost. Previously the ost of software was done during initial Electristar safety case. |
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Post by Deleted on Nov 28, 2012 16:52:48 GMT
4th rail the whole lot, ditch the 378s, and order a new batch to the S stock design. Standardisation at its best. The LO network is a whole different land compared to the SSR! It's a mainline railway dressed up as a metro service (I am not being negative about LO it's just how it is) and to run a railway like that you need a train like a 378. |
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Post by Deleted on Nov 28, 2012 17:59:01 GMT
It's not being negative about Lorol. It is what it is and if routes were converted to 4th rail trains could no longer operate beyond the tfl boundary not to mention the fact that tube drivers can't drive 378s as not mainline qualified.
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Post by andypurk on Nov 28, 2012 19:52:08 GMT
That is just what the current formations per unit are, not what is theoretically possible. It was explained to me that the base Electrostar design can't handle multiple pantograph cars in a single trainset, and a single pantograph car and associated power buses can only handle up to 5 cars. The multiple pantograph problem seems a bit weak reason, as an Electrostar train is quite happy with three pantograph vehicles in 12 cars. It would then come down to configuration, which as someone else has mentioned, may become expensive for a small fleet. Also, the class 395 sets on High Speed 1 as well as the class 460s which I already mentioned. Additionally there were some 6 car REP units formed during the electrification of the Weymouth line. Edit Additionally there are the Eurostar sets (and their cousins the TGVs in France with plenty more examples on the continent). But it won't just be reinstating disused platforms, as I mentioned above, all the stations west of Camden Road don't have disused parts to reinstate. Kentish Town West will be a particular problem (being on a viaduct), Caledonian Road might also be tight and something would need to be done to the layout at Clapham Junction, where the old platform 1 would probably need to be reinstated. |
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Post by andypurk on Nov 28, 2012 19:53:47 GMT
4th rail the whole lot, ditch the 378s, and order a new batch to the S stock design. Standardisation at its best. So, how are you going to deal with the Southern services on the West London Line and the electrically hauled freight both there and on the North London Line? |
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Post by bicbasher on Nov 28, 2012 20:13:42 GMT
I think one of the reasons why the ELL was converted bar the politics to NR standards was down to cost. I can imagine it'd be more expensive to convert the New Cross Gate to Crystal Palace/West Croydon section to 4th rail than convert the old LUL section and build a new section up to Dalston.
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Post by mrjrt on Nov 28, 2012 23:04:57 GMT
The multiple pantograph problem seems a bit weak reason, as an Electrostar train is quite happy with three pantograph vehicles in 12 cars. It would then come down to configuration, which as someone else has mentioned, may become expensive for a small fleet. ...Yes, but power isn't shared between units AFAIK, so it'd just be the control signals going through the couplers...each 4-car trainset would be drawing all its power through its own pantograph. |
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Post by crusty54 on Nov 29, 2012 6:30:14 GMT
I think one of the reasons why the ELL was converted bar the politics to NR standards was down to cost. I can imagine it'd be more expensive to convert the New Cross Gate to Crystal Palace/West Croydon section to 4th rail than convert the old LUL section and build a new section up to Dalston. Why would a short length of track (ELL) justify converting the rest of the line? Value for money would never have justified doing it. |
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Post by Deleted on Nov 29, 2012 9:33:34 GMT
Cheap fix? Put a regular Dellner coupling on the end of the 5th coach rather than whatever keeps the cars together at the moment and essentially you have a single ended 5 car unit if you can see what I'm getting at?
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Post by andypurk on Nov 29, 2012 11:32:16 GMT
The multiple pantograph problem seems a bit weak reason, as an Electrostar train is quite happy with three pantograph vehicles in 12 cars. It would then come down to configuration, which as someone else has mentioned, may become expensive for a small fleet. ...Yes, but power isn't shared between units AFAIK, so it'd just be the control signals going through the couplers...each 4-car trainset would be drawing all its power through its own pantograph. There are two potential problems with having two pantographs on a unit. 1) They are too close together and so the electrical pick up doesn't work correctly. The example of the class 377/2 and /5 shows that this wouldn't be a problem in a six car unit as the pantographs would have the same amount of intermediate vehicles as happens when can happen when two class 377 units are couples. 2) The power distribution system within a unit doesn't work, but that surely would depend on how a six car train is set up. We've already had the idea that a six car unit could be formed of two three car half units, but without cabs in the middle of the train. This is the same setup as the class 460s used. An alternative would be the method used in the class 390s, where one pantograph powers the whole train, but uses high voltage connections between the separate parts of the unit (the 9 car class 390 units are formed of two four car sections, each with a separate power system, and a trailer in the middle, whilst the 11 car units have a third power system for the two additional vehicles. A question would be could the Electrostar AC set up power four motor coaches, even if there was an extra trailer separating a single pantograph coach from the end motor? Any six car unit would need four motor vehicles and two trailers to keep to the current power to weight ratio (4+2 would be the same as the original three car units that were 2+1). And would any adaptation be cheap enough to under take, given the apparent current limits with the design. |
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Post by mrjrt on Nov 29, 2012 12:11:20 GMT
Cheap fix? Put a regular Dellner coupling on the end of the 5th coach rather than whatever keeps the cars together at the moment and essentially you have a single ended 5 car unit if you can see what I'm getting at? I do, and I like it a lot, as it maintains the walk-through nature of the train. Thinking about it, I have vague notions that it had occurred to me before...but I can't think why I forgot about the concept. It also sounds like a hell of a lot less expensive modification to make to the TSO cars than trying to convert them into PTSOs. My only concern would be if the software can handle not having two cabs on each trainset. ...oh, and great post andypurk. Excellent points. |
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Post by Deleted on Nov 29, 2012 13:04:38 GMT
It was explained to me that the base Electrostar design can't handle multiple pantograph cars in a single trainset Ah! So it's an issue with potential phase and voltage differences when transiting supply areas. Well that makes sense, then. The car limit is then down to how much current you can draw for the motor cars, and how much you can throw along the supply busses between units. I think the phase issue is red herring as each power car has a transformer and electronics which deal with phase control issue so that the "low voltage" control systems will work happily together when crossing from one phase to another. XF |
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Post by trt on Nov 29, 2012 13:43:49 GMT
Ah! So it's an issue with potential phase and voltage differences when transiting supply areas. Well that makes sense, then. The car limit is then down to how much current you can draw for the motor cars, and how much you can throw along the supply busses between units. I think the phase issue is red herring as each power car has a transformer and electronics which deal with phase control issue so that the "low voltage" control systems will work happily together when crossing from one phase to another. XF Low voltage, yes. Rectified and smoothed supply should be no issue, but any kind of AC bus must be unique to that pick-up, surely, or it could back-feed into the supply and trip the watch-dog circuits. |
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Fair points on the new build stuff like Willesden - but I feel the wider point stands - there's not going to be any heavy engineering required as was the case at Dalston Kingsland to get it to 4 cars...just reinstating disused lumps of platform and moving signals.
