Of course it is, and they are already being designed in detail if not being built, but that conversion doesn't deliver an intercity ambiance train like the 159, and there are only so many 319s and other similar units to go round.
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Possible Class 159/158 conversation to bi - modal
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Of course it is, and they are already being designed in detail if not being built, but that conversion doesn't deliver an intercity ambiance train like the 159, and there are only so many 319s and other similar units to go round.
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Note also there have been a number of transmission replacement options considered for 158/9s (some possibly already implemented?). Why not compare an electric transmission variant too. At least look at it seriously from an engineering POV to see if it's a runner.
D365
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What I can't quite get my head around is that some seem to be seriously underestimating the work that it would take to completely replace the existing hydraulic transmissions with an electric equivalent, not to mention the fitment of a DC bus into near-30 year old units that were never designed for it.
What benefit does that have over simply bringing in a new fleet in the next franchise?
What benefit does that have over simply bringing in a new fleet in the next franchise?
It depends if you are looking at it from the perspective of a ROSCO who owns a bunch of 158/159s and a whole load of new traction equipment, or not.
Quite possibly nothing, and there is also the problem of near term power system capability on the 3rd rail sections, some of the busiest on the entire network approaching Waterloo, but even so an electric transmission WITHOUT 3rd rail capability might still have merits for performance and reliability or maintenance cost nevertheless, or it might not be worth it. As an interested layman in the field I cannot judge if this is practical or worthwhile on a train of that age.
First I recoiled at the thought of the amount of work needed to completely re-traction vehicles that old and that were built for one purpose, and I'm glad my gut-feel is supported by our experts. Then I realised that given that 158s (and presumably 159s) are pretty good as they are - compared to a lot of our other DMU stock - and that as most lines have seen good passenger growth it would be far more logical to keep them as they are for lines that will not be electrified but can't really justify the cost of whole new fleets of rolling stock.
They could boost capacity by doubling up existing train lengths or increasing service frequencies, especially as they are fully compatible with their sisters. Electrified lines can have new or adapted bi-mode stock...
They could boost capacity by doubling up existing train lengths or increasing service frequencies, especially as they are fully compatible with their sisters. Electrified lines can have new or adapted bi-mode stock...
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D365
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If the desire was there to reuse their existing equipment, couldn't Porterbrook just ask Stadler or CAF to build new bi-mode stock and reuse the Vossloh kit?
Possibly but by doing it this way around, I would expect they'd get a reasonably secure future for the 158/159s (Either by persuading the DfT to force them to be used in the next franchise, or just through hoping that no TOC wants to replace a comfortable well suited bi-mode with something new), they get their use of their expensive new equipment, and they wouldn't have to pay for the cost of new stock.
D365
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I figure at least Porterbrook will have the experience of the Class 319s.
The existing transmissions on the 158s/159s are particularly inefficient and Richardo looked at replacing them with auto-boxes to increase efficiency and hence reduce emissions (the study was looking at reducing emissions, the same study looked at stop-start 66s etc.) Bombardier eventually got round to using mechanical transmission on the 172s.
Agreed but the old 660V limitation in the inner SW area due to the D stock on the District line has now gone so 750V or 825V (may be after 456 withdrawal) when replacing the equipment would radically reduce electrical loses overall.
50 out of 172 miles on the Exeter trip or 50 out of 84miles on a Salisbury trip are on 3rd rail.
Reducing NOx and PM emission in London could become very important
swt_passenger
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The recent franchise agreement also refers to the 444s being altered to draw more power so that a 10.444 can have the same performance as a 12.450.
Because they both use ABB equipment so the redesign costs would probably be more than the value of the recovered equipment.
The leasing cost of re-engineered 159s would be far lower than new hybrids. If it wasn't Porterbrook would even be considering this.
Being able to bolt a 600-700kg alternator to the underside of the floor is probably far easier than trying to bolt an engine raft to the floor as the existing engine mounts would have to be more heavily engineered to deal with loads from the drive shaft so the engine mountings could take some of the load of the alternator.
furnessvale
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Indeed! I am sure there are a few places in the provinces that would take 158/159 units of others hands and put them to use on pure non electrified routes.
D365
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Precisely. The difference between these and the Class 319s is that there's no shortage of routes where the 158/159 fleets could be put to use in the medium term with minimal adaptations to be made.
Interior refurbishments are a lot less risky than these proposed mechanical conversions, and new build offers a lot more choice in terms of unit design.
It wouldn't have made it as far as the franchise document if they weren't...
edwin_m
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With the 158 being the first aluminium bodyshell manufactured in quantity by BREL and also the first used in significant numbers in the UK, I wonder if there is some uncertainty on fatigue life. This is always finite with aluminium, a major problem for aircraft preservation, and the 158s did suffer some fatigue problems in early years. If so it might limit the remaining lifetime available to make back the cost of any major mods to units that are not far off 30 years old.
Kneedown
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Confused - whyever would we be running bi-mode Class 158/9s on the MML? They would be completely unsuitable in just about every way. Class 801 derivatives would be far better (even if I hate the seats!)
Ok, I think we may have crossed wires somewhere.
The original post I quoted read to me as if 802's were not needed for the MML, and that 100mph Flirt, or equivalent bi modes would suffice. I probably read it like that as the post I quoted was responding to MML 222 successor.
swt_passenger
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The separate areas were not individually supplied - the 660v restricted area was much larger than you’d think, and according to the last enhancement plan was still to be completely upgraded, with a regulated output (completion) of Jan 2018.
The 660V area* was/is massive as it was never upgraded when most of the rest of 3rd rail land was upgraded to 750V over the years. The Waterloo and City Line was (is) fed from BR supplies as are parts of the district line hence Putney too being in the 660V area.
* Most / all of the Raynes Park electrical control room area???
swt_passenger
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The text of the DC regeneration project that started in CP4, and is only just finishing in the remaining parts of Wessex route, implies that the entire suburban area of all 3 routes including Kent and Sussex was still 660v until about 2012.
This is non-intuitive because the whole ‘Southern’ Network was almost always described as a 750 V system.
This is non-intuitive because the whole ‘Southern’ Network was almost always described as a 750 V system.
If the 769 trial goes well then there is a good case for converting (as opposed to building completely new trains) many of the existing 319s given the lack of DMUs Northern Rail have to adequately phase out the Pacers. But at the moment the 319s are poorly suited to some of the lines they operate - the Manchester Airport stopper being an obvious one as it shares the busy line with many express services.
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Wychwood93
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We are drifting slightly off thread here, but, the PSUs were done some years ago - pre-2004 if I recall correctly. I was in the portakabin complex below Easteligh box at the time and a fellow portakabinista had been on the PSU stuff. Regarded then, when it was done, as being, shall we say, not as good as it could have been. I would hate to mention the 'traction current index' words, but, essentially a 4-REP, 2x442 represented what you could manage - 444s/450s are the same. Watts do indeed equal volts multiplied by amps. The laws of physics apply, as ever. Modern traction packages, three phase drive etc. are better at delivering initial 'grunt' - the SWR Desiro kit can easily do acceleration of 1 mph/sec up to about 40 and then drift away. A 465 unit is easily (well done BR!) capable to get to 60 in less than a minute (lower gearing - before anyone mentions it!). Ditto for an IET 800 going west from Reading.
At the funeral of a former railway chum last autumn I heard that the 444s might have their gearing altered. Does anybody else have knowledge of this?
edwin_m
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A three-phase motor as fitted to all post-privatisation EMUs has the ability to sustain torque to a much higher speed than a traditional DC motor. Therefore a train with these motors has better acceleration performance at the top end of its speed range, but needs to draw more power to do so. On the third rail that isn't possible due to the various limitations of the system, so the trains are limited in the current they can draw and hence in their power and acceleration particularly at higher speeds. They are also heavier than the trains they replace, and need power for aircon and other systems the old trains didn't have.
I don't know what is happening with 444s but perhaps they have decided that the current limit can be increased because they were too conservative with it previously, or because of the advent of regenerative braking, or they might have improved the supply.
I don't know what is happening with 444s but perhaps they have decided that the current limit can be increased because they were too conservative with it previously, or because of the advent of regenerative braking, or they might have improved the supply.
Or because the DfT has rewritten the laws of physics, and that pesky science can't tell them what to do!
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