Possible Class 159/158 conversation to bi - modal

[The Ham]

The below are taken from the SWR franchise thread, what are people's views?

I thought starting a new thread would open it to a wider audience.

The Franchise agreement has now appeared on the DfT website, including a rather odd requirement to look at the feasibility of converting their ~30 year old DMUs into bi-modal DEMUs.

?!?!?!?!?!?!?!?!?!? what sort of idiots do the have working at the DFT? converting DEMU's or EMU yes but DMMUs? the would surely need some quite heavy modification, not least finding space for both traction convertors, motors AND still have space for an engine with enough power not only to not impede acceleration but to be able to operate at a minimum of 90mph.

It is only a feasibility study, but it is one that I could probably write right now! I suspect the answer may come back as "try again with more appropriate stock" - but seeing it in the franchise agreement really hammered home that bi-mode is flavour of the month/year/parliament at the DfT

Seeing as BR had serious proposals around 1990 to extend 3rd rail to either Salisbury or Exeter it’s a shame going by what you suggeting we’re unlikely to be any further forward almost 30 years later.

Strictly speaking they are DHMUs not DMMUs.

But the point is very valid. Why is there this obsession with UPOW* multiple units?


* Under Powered Over Weight

I would like to see electrification extended West from Basingstoke, however I would guess that it's likely to happen in stages (i.e. possibly taking over 5 years) to reach all the way to Exeter and so I can see the logic in having units that can take advantage of the new wires.

However where it could really be beneficial is once the wires reach Yeovil and SWR can then replace the units with straight EMU's. As then other areas could then have access to the 158/159's. My guess would be that they would be preferable to the converted 319's not least due to their air conditioning.

It could also mean that (given the SWR have funded the first units) the rest of the 158 fleet could follow as the big development costs have been covered, making the cost per unit for the rest of the fleet less than what the SWR fleet had cost.

 

[cjmillsnun]

Bi Mode conversions of 158/9s is a joke. Sadly what I can see them finding feasible is the hybrid 319s or worse hybridising 455s. This would be a downgrade of what are very well suited units for the routes they serve.

 

[Domh245]

It has been suggested elsewhere that this is mainly an attempt to try and get a bit more value out of the Vossloh traction equipment recently fitted to a bunch of soon to be retired EMUs, and that it isn't a DfT scheme (it's likely to be Porterbrook who've paid for the new traction equipment and want to get a bit more value out of it)

But thinking in terms of the wider network it's not the most sensible plan forward. Buying new dedicated bi-modal* units to replace all of the SWR 158s and 159s, and then sending the DMUs (without retractioning) wherever else the capacity is needed (EMT, Northern) would be far more sensible.

*Assuming that you are sure about wanting to eliminate diesel running where possible. The London end power supply may melt under the strain of these heavy EMUs in addition to the new suburban stock and the uprated 444s

 

[MatthewRead]

I was going to create a thread about this but I was reluctant no one else seem to know. Natalie Bennet of the Green party said she wanted all diesel engines replaced with battery equipment but I was told that would be far too expensive re-tractioning all of the DMU fleet.

 

[D365]

Now this is a “My Idea” thread if I ever saw one...

 

[fowler9]

Mad idea. I don't have the slightest clue how this would work or what the thinking is behind it. If anyone can tell me I would be happy to learn.

 

[The Ham]

Now this is a “My Idea” thread if I ever saw one...

Although I started the thread, the idea came from the franchise document between the DfT and SWR (see the first quoted post). Although I do agree it does sound like something that if someone on here came up with they'd be told to put their crayons back in their box.

 

[Clansman]

What would be the benefit in adding 3rd Rail shoes to the SWR 158/159 fleet? Modifying them for the sake of being able to use third rail for a fraction of the journey is just a waste of money that poses zero major benefit to the passengers.

Better use of money to wait until it's time to introduce newer rolling stock on the lines the 158/159s operate.

 

[Domh245]

Although I started the thread, the idea came from the franchise document between the DfT and SWR (see the first quoted post). Although I do agree it does sound like something that if someone on here came up with they'd be told to put their crayons back in their box.

I think @D365 meant "my thread" in the context of his research into new IPMUs

And as I suggested earlier, one of the main possible reasons for this is for porterbrook to get a few more years use out of their new vossloh traction equipment

 

[AngusH]

I'm mystified... could the whole diesel engine somehow be replaced with a hybrid system? (so keeping the transmission) or does this replace everything and convert them to be diesel electric multiple units?

I'd also be impressed if the cost can be kept down to the point that makes it worth while

It sounds like something that could perhaps be done, if it's an order and cost isn't a concern, but whether it makes sense...

 

[The Ham]

But thinking in terms of the wider network it's not the most sensible plan forward. Buying new dedicated bi-modal* units to replace all of the SWR 158s and 159s, and then sending the DMUs (without retractioning) wherever else the capacity is needed (EMT, Northern) would be far more sensible.

*Assuming that you are sure about wanting to eliminate diesel running where possible. The London end power supply may melt under the strain of these heavy EMUs in addition to the new suburban stock and the uprated 444s

Although extra units would be ideal, there may not be enough capacity to build new units. Especially given that EMT are currently being told they need to have new bimodal trains to replace their 222's and many here would like XC to get more units.

Likewise GWR and Chiltern may want new units too. Which again are likely to be bimodal.

As I indicated on the other thread (and quoted above) it could mean that all the 158's become bimodal units, which some could think was a good way of reducing the number of trains that have to run under the wires.

 

[D365]

Notwithstanding the ongoing concerns with the 769 conversion, surely a “455 Flex” with a suitable interior would be an order of magnitude more justifiable.

Actually, the 769 is as a good a reason as any for why this is even less likely to be achievable.

 

[Domh245]

Although extra units would be ideal, there may not be enough capacity to build new units. Especially given that EMT are currently being told they need to have new bimodal trains to replace their 222's and many here would like XC to get more units.

Likewise GWR and Chiltern may want new units too. Which again are likely to be bimodal.

As I indicated on the other thread (and quoted above) it could mean that all the 158's become bimodal units, which some could think was a good way of reducing the number of trains that have to run under the wires.

They don't need to be high speed Hitachi bi-modes though - I'd suggest that some 100mph FLIRTS or some CAF offering perhaps would be more than enough for to replace these units.

These conversions would be 750V DC bimodes, so would only be of any use to the SWR and GWR fleets - it's of no use to EMT, Northern, or Scotrail who would want 25kV bi-modes. Although if they're looking into bi-modalling these units in the first place then perhaps cutting chunks of roof off to fit a pantograph wouldn't be too far fetched.

 

[broadgage]

For the reasons already given by others this does not sound very sensible.
The only way I could see of doing this would be to build new vehicles that could be added to say a 3 car 159 unit to make it a 4 car hybrid unit.
The extra vehicle would have sufficient electric power to move all 4 vehicles at the desired performance. Diesel performance would be reduced by now having 3 vehicles out of 4 powered instead of all 3. That might be acceptable of course if the intended use was a route with the faster bits electrified.
It would still be more sensible to build new bi-mode trains, and to re deploy the existing DMUs to a route where the extra capacity is needed.

And what about the air conditioning ? mechanically driven by the engine at present IIRC.

 

[D365]

And what about the air conditioning ? mechanically driven by the engine at present IIRC.

Mechanically driven in so much as an electrical alternator as an intermediary...

It would still be more sensible to build new bi-mode trains, and to re deploy the existing DMUs to a route where the extra capacity is needed.

That's exactly it, how would the chopping and changing of near-30 year old DMUs bring about any kind of benefit?

 

[3141]

IF it was a 455 Flex it would be too slow to maintain the current timetable for class 159s, unless they could regear it. Further west there are sections such as Honiton Bank that need powerful engines if speed is going to be maintained. If I was producing a feasibility study I'd start by listing what the train is required to be capable of doing, then look at what could be done to add electric traction to a 159 or diesel to a 455 or whatever, and I think a conclusion would quite quickly become evident.

Now I wonder - what sort of diesel engine could you get under a 458? Ian Walmsley suggested that for the Marshlink line.

 

[Cowley]

This really does seem to be a problem looking for a problem.
It’d be an enormous amount of work to fit more equipment onto a 159 surely? Let alone the extra weight.
And if you were going to stick an extra coach in for these bits then that’d be complicated too, it’d be easier just to put an electro diesel locomotive on the front. Class 75 anyone? Better add a wink (they’d have to be a rebuild of something we’ve got lots of but with replacement modern quiet engines... How many 50s are left?)

 

[D365]

This really does seem to be a problem looking for a problem.

Isn’t that a railway speciality

 

[47271]

And what about the air conditioning ? mechanically driven by the engine at present IIRC.

If we're talking about 158s I wouldn't worry about that, however it's powered the aircon doesn't work anyway.

 

[swt_passenger]

If we're talking about 158s I wouldn't worry about that, however it's powered the aircon doesn't work anyway.

Aircon almost always works fine on Salisbury’s 158/159 fleets though...

 

[47802]

Probably this is some sort of nonsense the SWR bid team came up with to avoid buying new trains for this route without a cat in hells chance of it ever happening

 

[47271]

Aircon almost always works fine on Salisbury’s 158/159 fleets though...

Fair enough, I never travelled on a SWT diesel unit with broken aircon.

I wish I could say the same for other operators' 158s.

 

[gazthomas]

And if you were going to stick an extra coach in for these bits then that’d be complicated too, it’d be easier just to put an electro diesel locomotive on the front. Class 75 anyone? Better add a wink (they’d have to be a rebuild of something we’ve got lots of but with replacement modern quiet engines... How many 50s are left?)

Or 442s with a 73

 

[MatthewRead]

Or 442s with a 73

That has been mentioned before on another thread

 

[MG11]

I don't think bi modes would be bad idea, all things considered. They would be using third rail, so there would be no need to interfere with the roofing structure and I think these units do still have a fair few years left in mainline service.

 

[Bletchleyite]

It's vastly, vastly easier to convert EMUs to bi-modes by just adding a generator or two (be that under or above floor) than it is to convert DMUs to bi-modes (with the need to add all sorts of electrical gubbins etc).

 

[Kneedown]

They don't need to be high speed Hitachi bi-modes though - I'd suggest that some 100mph FLIRTS or some CAF offering perhaps would be more than enough for to replace these units.

Whatever is ordered must be 125mph capable.

 

[Bletchleyite]

Whatever is ordered must be 125mph capable.

Why? 100mph would be quite adequate.

 

[northwichcat]

It's vastly, vastly easier to convert EMUs to bi-modes by just adding a generator or two (be that under or above floor) than it is to convert DMUs to bi-modes (with the need to add all sorts of electrical gubbins etc).

Also makes a lot more sense. Finding future homes for 158s and 159s without conversion would be easy, finding future homes for off-lease EMUs without some being converted to bi-mode isn't so easy.

 

[furnessvale]

It's vastly, vastly easier to convert EMUs to bi-modes by just adding a generator or two (be that under or above floor) than it is to convert DMUs to bi-modes (with the need to add all sorts of electrical gubbins etc).

Indeed! Unless the DMUs are actually DEMUs the electrical gubbins also runs to traction motors etc.

If they couldn't justify doing Voyagers, what chance would any DMU have?