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Drogheda (in Ireland) has conductor bars for the purpose of charging the new DART trains, presumably at 1500V DC, given that is what the DART uses in Dublin already.
That is a modern example of how such a set-up could be designed for charging in platforms.
Maybe. Batteries will need replacing far more often than OHLE and they are far from cheap...my car's battery pack replacement cost is £30K so the cost of replacing the traction batteries on a fleet of BEMUs several times over the lifespan of the trains is going to rival that of an OHLE installation...which only needs to be done once, not every few years.
Besides, Google the phrase "lithium evaporation pans" and your notion that these things are the environmental panacea we've been told they are might well take a bit of a beating.
Replacing batteries in a BEMU doesn't require you to close the railway though. Considering electrification is multiple millions per single track km as well as the ongoing maintenance I'd like to see some figures comparing the two.
This is a general discussion about battery trains, we don't have the information to design specific schemes. The point is that Oxford has existing 25kV only 10 miles away at Didcot, and Leicester will have 25kV about 5 miles away at Wigston. Ways can be devised to take advantage of that without wiring all of Oxford or Leicester.
Well with Oxford and Leicester there are already nearby electrified sections, as you mentioned. I think the more important aspect of discussion is what to do with stations like Sheffield where many services currently run under no electrified track.
Straight EMUs can also have some expensive mid-life equipment upgrades for example the new traction packages on the class 465s. HSTs were all re-engined mid-life. Replacing batteries may need to be done a bit more often, but it is a much more simple task than either of these.
But surely battery EMUs might also require things like new traction packages? I can't see anything different about BEMUs that would mean that they would never require something like that.
Drogheda (in Ireland) has conductor bars for the purpose of charging the new DART trains, presumably at 1500V DC, given that is what the DART uses in Dublin already.
That is a modern example of how such a set-up could be designed for charging in platforms.
The Filton lines (Doctor Days Bridge Junction to Patchway / Stoke Gifford junctions) is already planned to be done.
Bath Spa itself (and Sydney Gardens area) maybe (because of the different design required, this may be done later). But some of the other simple plain line sections between Bristol Temple Meads and Bathampton Junction absolutely yes.
I think Bristol Temple Meads is essential due to nearly all passenger trains stopping there, and the number of services that have long dwell times there or which terminate / start from there. The alternative would be to only provide OHLE for the carriage lines at Bedminister, but that then means trains have to shunt to/from there, then wait while the battery recharges. And only two trains could be accommodated with the current arrangements (unless you expand the OHLE to other sidings). This may be fine if it was only one or two local services that were formed of BEMUs and which started/terminated at BTM. But would be unsuitable for a more intensive service.
I could see there being an argument for wiring to Parson Street Junction and quad tracking that, to enable stuff to start to accelerate to the 90mph limit on electric and increasing number of local services from 1tph to 2tph.
Maybe. Batteries will need replacing far more often than OHLE and they are far from cheap...my car's battery pack replacement cost is £30K so the cost of replacing the traction batteries on a fleet of BEMUs several times over the lifespan of the trains is going to rival that of an OHLE installation...which only needs to be done once, not every few years.
Besides, Google the phrase "lithium evaporation pans" and your notion that these things are the environmental panacea we've been told they are might well take a bit of a beating.
The key point with battery trains is that it is no longer essential to bring the power to the train, it is also possible to take the train to the power supply. In a lot of cases taking the train to the power supply is going to be cheaper.
I think in the majority of cases capacity for ECS moves has been used up over the years. For somewhere like Euston only peak extras come out of the sidings. If all EMUs needed charging then Camden sidings would have to be a lot larger, there would be more stock required as it would not be so productive and twice the number of EMU movements would be required (ignoring the comparatively few peak extras). It is far better to charge them on the move.
For somewhere like Leeds Neville Hill would have to be supplemented so it could charge all those DMU substitutes.
The battery designed for the trial was cobbled together out of Nissan Leaf batteries, I believe.
They may want to create a purpose built design before proceeding to series production
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Even the optimistic estimates for electrification put it at £2.5m/stkm and up
You can buy an awful lot of batteries for that. Additionally lithium is a capital expenditure, once the first generation of batteries is procured only limited additional metal is required for later years.
Let us not forget a good proportion of electrification will still be required unless the batteries have huge range (so heavy and expensive) and expensive fast charging facilities (costing battery life). On the face of it if only 50% of a route is electrified then that electrified part will have to supply roughly twice the power it would have needed to if the whole route was electrified.
Let us not forget a good proportion of electrification will still be required unless the batteries have huge range (so heavy and expensive) and expensive fast charging facilities (costing battery life). On the face of it if only 50% of a route is electrified then that electrified part will have to supply roughly twice the power it would have needed to if the whole route was electrified.
A battery of a couple hundred kilometres reliable range and able to charge in about twenty to forty minutes could eliminate a huge portion of diesel operation with only very limited additional electrification.
Such a battery appears well within the state of the art.
25kV systems are not traditionally limited by thermal rating. I believe upgrades would focus around grid supplies rather than having to do disruptive and expensive work to the overhead lines themselves.
A battery of a couple hundred kilometres reliable range and able to charge in about twenty to forty minutes could eliminate a huge portion of diesel operation with only very limited additional electrification.
Such a battery appears well within the state of the art.
25kV systems are not traditionally limited by thermal rating. I believe upgrades would focus around grid supplies rather than having to do disruptive and expensive work to the overhead lines themselves.
I would expect the contact wire to need to be beefed up. If 10% of a route was electrified then it would need to carry ten times the current of normal catenary.
I would expect the contact wire to need to be beefed up. If 10% of a route was electrified then it would need to carry ten times the current of normal catenary.
Maybe. Batteries will need replacing far more often than OHLE and they are far from cheap...my car's battery pack replacement cost is £30K so the cost of replacing the traction batteries on a fleet of BEMUs several times over the lifespan of the trains is going to rival that of an OHLE installation...which only needs to be done once, not every few years.
I highly doubt the battery costs £30k! I mean, sure, a dealer might say that's what you'd pay and spare parts are often extremely expensive compared to the component costs, but that is NOT the price for the battery (if it was, you wouldn't be seeing EVs selling in China for £5000). A Nissan Leaf replacement battery from Nissan itself in Japan is under £2,500, and third-party refurbs are far less.
Would you buy a new battery on your EV anyway when you've reached 200,000 miles and the SoH has dropped to 75-80% (maybe still higher than that)? How old will the car be by then? Surely you'd get a refurbished one? Companies now can do amazing things with battery modules to balance things and give a whole new life.
The same will apply for trains, where you'll have far larger capacity batteries so the number of charge cycles will be comparable to an EV. I am not sure why you would think they'd need changing every three years? It will obviously be worth keeping the train and changing the battery, and I'm sure they'll be very quick and easy to swap.
Ideally, the railway will look to creating standards so one battery module fits multiple different trains, from different vendors.
I could see there being an argument for wiring to Parson Street Junction and quad tracking that, to enable stuff to start to accelerate to the 90mph limit on electric and increasing number of local services from 1tph to 2tph.
There's a very strong argument for electrifying it. Quad-tracking less so, as Down services just need to depart Temple Meads in the right order. What really needs to happen though is to add/move the pointwork to allow Up trains from Nailsea & Backwell to call at Platform 3 at Parson Street so that during late running it can get out of the way quicker.
How long would it take to electrify say Bristol to Exeter, then down to Basingstoke and thence to Reading? Then the Midland main line, most likely at least two parliamentary terms, so it's very unlikely because if there's a change of government, they will scrap any plans, to spend money on the network, preferring to sell it off.
The best short-term route, would be to place an order for a new fleet of tri mode, EMU's that can operate on Overhead, 3rd Rail, and Battery, to replace diesel traction, on Southern and GWR services, the DMU's that are not life expired can then be relocated to other regions, and a limited amount of electrification, and fast charging grids at some stations, to supplement the current collection whilst either running on overhead, or 3rd rail to allow the batteries maximum range
I would expect the contact wire to need to be beefed up. If 10% of a route was electrified then it would need to carry ten times the current of normal catenary.
Not if the system was a bit intelligent. Don't charge up the battery when the train is avcelerating, or using very high loads, instead charge when the train is coasting or decelerating. The overhead is designed to cope with heavy loads that don't occur for a big percentage of the time. Evening out the peaks and troughs using battery charging would probably reduce wear on the system, and make the currents easier to cope with (not necessarily to the point that you could charge in 10% of the time without an upgrade of course)
Let us not forget a good proportion of electrification will still be required unless the batteries have huge range (so heavy and expensive) and expensive fast charging facilities (costing battery life). On the face of it if only 50% of a route is electrified then that electrified part will have to supply roughly twice the power it would have needed to if the whole route was electrified.
This isn't correct. Let's take the Cambridge/Ely area as an example. The existing grid feeders supply power for lots of straight electric trains running to/from London. Now suppose that Stansted-Norwich, Stansted-Peterborough and Cambridge-Ipswich go over to battery bimodes. The amount of extra power required will be a small proportion of the total.
You are right that it is better to charge on the move, but it won't need different contact wire. When a battery bimode is using lots of power for propulsion, it won't be recharging its batteries. When a battery bimode is using little or no power for propulsion (which is most of the journey), is when it be recharging its batteries.
You are right that there is a cost here, but there will be instances where it is a lot less costly than OHL. And you exaggerate the number of additional movements required. In most circumstances it is likely to only involve one recharge about halfway through the day, when the service is at off peak level. Providing that the battery EMUs have multiple working, they won't all have to go to/from the sidings for recharging as separate movements.
Very pedantic gripe - if Overhead, Third Rail and Battery makes something a Tri-Mode, then a Class 700 is a Bi-Mode! Dual-Voltage Bi-Mode would be a better description of a Battery/OLE/3rd Rail unit.
EDIT
I think I miss understood your last sentence to mean 600MW per diesel train.
Perhaps you mean all diesel trains on average ?
OR is it 600KW per average diesel train ?. OKay. I think you meant the contact wire can handle 15,000MW ?. In which case 25 electric trains (if using 600MW diesel equivalent). But what proportion of a continuous line rating would you be exceeding ?.
I am thinking of parts of the WCML (Crewe to Liverpool) and the ECML (Newcastle to/from Edinburgh) which already rely on Bi-Mode trains to run on diesel due to limitations. If they were battery then would charging on adjacent sections take those sections to or beyond their limit.
Not if the system was a bit intelligent. Don't charge up the battery when the train is avcelerating, or using very high loads, instead charge when the train is coasting or decelerating. The overhead is designed to cope with heavy loads that don't occur for a big percentage of the time. Evening out the peaks and troughs using battery charging would probably reduce wear on the system, and make the currents easier to cope with (not necessarily to the point that you could charge in 10% of the time without an upgrade of course)
If we say that 50% of the time the train is drawing lots of power for immediate use (probably pessimistic) that would double the amount of line required to be electrified. So in my example that would take coverage to 20% assuming the OHLE would need to take on average (over its length) ten times the normal demand. Actually there will be service patterns where the electrification is not in the right place so maybe more needed. I agree the wiring required might be a lot less than continuous.
This isn't correct. Let's take the Cambridge/Ely area as an example. The existing grid feeders supply power for lots of straight electric trains running to/from London. Now suppose that Stansted-Norwich, Stansted-Peterborough and Cambridge-Ipswich go over to battery bimodes. The amount of extra power required will be a small proportion of the total.
I agree this is the beauty of battery trains. They can cover routes that stray off the core heavily used electrified route. Some of the Great Western branches might apply - if they run far enough on the mainline OTHERWISE it requires fast charging at one or both ends.
It is a bit like any suburban area electrified can use battery trains for lesser used routes that go not far beyond. Stratford-Upon-Avon could be reachable from Birmingham if the OHLE only gets as far as Tysely from Birmingham. A Stratford-Upon-Avon to Leamington shuttle might struggle if the core route Birmingham to Leamington does not provide enough charging opportunity at the Leamington end - then it is fast charging at one or both ends.
I would hope the third rail has enough capacity to charge a Battery unit to Uckfield. Certainly London Bridge to South Croydon must have plenty of power as it is such a busy route.
I wonder how likely it is that a Battery EMU would have the capability to charge off BOTH the OHLE AND off a fast charge rail ?.
Would they be a separate design of units ?.
As an aside I do see the Uckfield route as an early/urgent adopter of battery units. Maybe with a fast charge rail at Uckfield just to make sure.
You are right that it is better to charge on the move, but it won't need different contact wire. When a battery bimode is using lots of power for propulsion, it won't be recharging its batteries. When a battery bimode is using little or no power for propulsion (which is most of the journey), is when it be recharging its batteries.
You are right that there is a 9scost here, but there will be instances where it is a lot less costly than OHL. And you exaggerate the number of additional movements required. In most circumstances it is likely to only involve one recharge about halfway through the day, when the service is at off peak level. Providing that the battery EMUs have multiple working, they won't all have to go to/from the sidings for recharging as separate movements.
In the case of Camden the peak extras would get plenty of time to charge during the day I hope. Perhaps they could rotate out of Camden sidings to let other units in. It will be a balance of how long a unit needs to charge vs the penalties of extra ECS moves. Camden is a bad example I suppose as very few units stray of the OHLE of course !.
If we start from scratch for an example then perhaps the Snow Hill lines in Birmingham
- where would the sidings go ?.
- how much of the route has capacity for extra ECS moves ?.
I would hope for almost continuous electrification of the main UK routes, using battery to get past the difficult bite. Then for lesser routes I am very tempted by charging on the move mainly. But with a fast charge rail, only if required, at the end of longer branches where dwell times are irrelevant to service provision. The busier a route then the more justification for more wiring. But battery caters for lightly used lines/routes that are a long way down the electrification queue.
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Very pedantic gripe - if Overhead, Third Rail and Battery makes something a Tri-Mode, then a Class 700 is a Bi-Mode! Dual-Voltage Bi-Mode would be a better description of a Battery/OLE/3rd Rail unit.
I agree some new short names need to be come up with !.
Dual might cover the nature(s) of the electricity supply *.
Bi and Tri catering for different energy sources.
The nature of the electricity supply is a big deal as 25KV AC infers a transformer is needed but then 750V DC infers an inverter is needed !.
A battery of a couple hundred kilometres reliable range and able to charge in about twenty to forty minutes could eliminate a huge portion of diesel operation with only very limited additional electrification.
Such a battery appears well within the state of the art.
The problem with that plan is that the more time a train needs to spend charging during the day, the less intensively they can be diagrammed. In many cases, this would entail needing more trains in service to run the same timetable.
It works for the Greenford branch, because the train is getting a shot of electrons every 30 minutes, and so it doesn't take long to replenish the battery enough to run the next 5 mile round trip, and so even if the train is running late and doesn't get the full turnaround time at West Ealing, the time needed for the driver to change ends is likely to be long enough to put enough charge in for the next round trip.
Now compare that with a longer rural route. Scarborough to Sheffield is 113 miles, so within that range although there's not a lot to spare, so the train will need a full charge at each end or additional charging stops along the way. The only stop where that is practicable is at Hull, where it is timetabled 6 minutes stand time as it reverses. It then has 20 minutes layover at Scarborough and less than 10 minutes at Sheffield. But you need most of that stand time for reliability, if you're using all of it for charging then you've got no chance of recovering from delays. And even if you could use all of the stand time at Scarborough, Hull and Sheffield for charging, it's unlikely that you would get enough juice back into the batteries to run the next trip. So now instead of using 6 units to run an hourly service, you've got to use 7 or maybe even 8 depending on whether you can shift the service in one direction by 30 minutes without messing up pathing and coordination with other services.
Sure, that won't be the case on all lines, there will be some where the current diagramming does have enough slack to accommodate sufficient charging time, but that certainly won't be the case for a lot of routes. And now that you need more trains and potentially more crew to maintain the existing level of service, it isn't looking so efficient to rely on batteries and fast charging, and the cost may shift back towards more electrification.
The problem with that plan is that the more time a train needs to spend charging during the day, the less intensively they can be diagrammed. In many cases, this would entail needing more trains in service to run the same timetable.
It works for the Greenford branch, because the train is getting a shot of electrons every 30 minutes, and so it doesn't take long to replenish the battery enough to run the next 5 mile round trip, and so even if the train is running late and doesn't get the full turnaround time at West Ealing, the time needed for the driver to change ends is likely to be long enough to put enough charge in for the next round trip.
Now compare that with a longer rural route. Scarborough to Sheffield is 113 miles, so within that range although there's not a lot to spare, so the train will need a full charge at each end or additional charging stops along the way. The only stop where that is practicable is at Hull, where it is timetabled 6 minutes stand time as it reverses. It then has 20 minutes layover at Scarborough and less than 10 minutes at Sheffield. But you need most of that stand time for reliability, if you're using all of it for charging then you've got no chance of recovering from delays. And even if you could use all of the stand time at Scarborough, Hull and Sheffield for charging, it's unlikely that you would get enough juice back into the batteries to run the next trip. So now instead of using 6 units to run an hourly service, you've got to use 7 or maybe even 8 depending on whether you can shift the service in one direction by 30 minutes without messing up pathing and coordination with other services.
Sure, that won't be the case on all lines, there will be some where the current diagramming does have enough slack to accommodate sufficient charging time, but that certainly won't be the case for a lot of routes. And now that you need more trains and potentially more crew to maintain the existing level of service, it isn't looking so efficient to rely on batteries and fast charging, and the cost may shift back towards more electrification.
This is why I feel significant sections of overhead wiring are needed. This is most feasible where a secondary service spends a lot of time under the wires of a more important route. Electrifying Sheffield area might be enough if bits either side of the ECML are included ?.
OKay. I think you meant the contact wire can handle 15,000MW ?. In which case 25 electric trains (if using 600MW diesel equivalent). But what proportion of a continuous line rating would you be exceeding ?.
It is definitely 15MW, 15GW would be impressive (Approx 6 x capacity of Drax). GMRT2111 Rolling Stock Subsystem and Interfaces to AC Energy Subsystem standard generally uses 300A as standard for an OLE section (Single track line) and maximum train current so that is 7.5MW. However in Auto-Transformer land - current will flow both ways to ATs at each end, so you can double that to 15MW. Then once outside the secondary circuit, so between primary feeder and Auto-Transformer, current is halved, so a 300A train will also only apply 150A load.
>300A is used in GB, as well as < 300A, but 300A is the standard.
Extract of guidance from GMRT2111 on how current demand of trains is controlled based on Infrastructure.
Guidance G 3.2.6 A facility to set the maximum current as set out in LOC&PAS NTSN clause 4.2.8.2.4 allows different values to be selected for different routes, thus permitting different classes of train sets to be used across the GB mainline 25 kV ac electrified railway. Methods by which this function might be achieved include:
a) A variable current power controller where different positions selected by the driver allow different current limits;
b) Driver selectable current demand profiles, either by provision of a switch or via the Train Control and Management System (TCMS);
c) Automatically selected current demand limits by off vehicle systems, for example, by European Traffic Control Systems (ETCS) or Radio Frequency Identification (RFID) tags;
d) Selectable current limits adjusted during maintenance; or
e) Automatic variation of the current limit dependent on the train set formation.
Very pedantic gripe - if Overhead, Third Rail and Battery makes something a Tri-Mode, then a Class 700 is a Bi-Mode! Dual-Voltage Bi-Mode would be a better description of a Battery/OLE/3rd Rail unit.
I agree some new short names need to be come up with !.
Dual might cover the nature(s) of the electricity supply *.
Bi and Tri catering for different energy sources.
The nature of the electricity supply is a big deal as 25KV AC infers a transformer is needed but then 750V DC infers an inverter is needed !.
The problem with that plan is that the more time a train needs to spend charging during the day, the less intensively they can be diagrammed. In many cases, this would entail needing more trains in service to run the same timetable.
Now compare that with a longer rural route. Scarborough to Sheffield is 113 miles, so within that range although there's not a lot to spare, so the train will need a full charge at each end or additional charging stops along the way. The only stop where that is practicable is at Hull, where it is timetabled 6 minutes stand time as it reverses. It then has 20 minutes layover at Scarborough and less than 10 minutes at Sheffield. But you need most of that stand time for reliability, if you're using all of it for charging then you've got no chance of recovering from delays. And even if you could use all of the stand time at Scarborough, Hull and Sheffield for charging, it's unlikely that you would get enough juice back into the batteries to run the next trip. So now instead of using 6 units to run an hourly service, you've got to use 7 or maybe even 8 depending on whether you can shift the service in one direction by 30 minutes without messing up pathing and coordination with other services.
Well, in this particular case a handful of electrified track kilometres (I have proposed Dore to Meadowhall) would provide quite a lot of charging time.
Ten minutes Meadowhall to Sheffield, approaching ten minutes layover and then ten minutes back.
Sure, that won't be the case on all lines, there will be some where the current diagramming does have enough slack to accommodate sufficient charging time, but that certainly won't be the case for a lot of routes. And now that you need more trains and potentially more crew to maintain the existing level of service, it isn't looking so efficient to rely on batteries and fast charging, and the cost may shift back towards more electrification.
You wouldn't need more crew in any case I don't think. But even so most of these edge cases can be eliminated with a small number of additional track kilometres of electrification.
Probably less than the remaining uncommitted track kilometres in the envisaged MML scheme
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OKay. I think you meant the contact wire can handle 15,000MW ?. In which case 25 electric trains (if using 600MW diesel equivalent). But what proportion of a continuous line rating would you be exceeding ?.
15MW per train is about the maximum the copper could take.
The 610MW figure is the average heat output of a fire that consumed all the diesel used on the railway.
Given the efficiency of diesel engines is under 50%, the average amount of power that has to be provided to trains to convert them to batteries will be 200-300MW across the entire system.
I am thinking of parts of the WCML (Crewe to Liverpool) and the ECML (Newcastle to/from Edinburgh) which already rely on Bi-Mode trains to run on diesel due to limitations. If they were battery then would charging on adjacent sections take those sections to or beyond their limit.
True, and for practical reasons we wouldn't be switching all DMUs to BEMUs at the same time. So we should start with the easy routes that spend enough time under electrification already, and cascade the DMUs released to other routes that do need some infrastructure work.
There are a lot of 15x and 16x nearing their end of life. Ideally, their replacements would not include diesel power at all, only EMUs and BEMUs, cascading the still good DMUs (e.g. 170s, 19x) to those routes that need DMUs for now.
Now compare that with a longer rural route. Scarborough to Sheffield is 113 miles, so within that range although there's not a lot to spare, so the train will need a full charge at each end or additional charging stops along the way. The only stop where that is practicable is at Hull, where it is timetabled 6 minutes stand time as it reverses. It then has 20 minutes layover at Scarborough and less than 10 minutes at Sheffield. But you need most of that stand time for reliability, if you're using all of it for charging then you've got no chance of recovering from delays. And even if you could use all of the stand time at Scarborough, Hull and Sheffield for charging, it's unlikely that you would get enough juice back into the batteries to run the next trip. So now instead of using 6 units to run an hourly service, you've got to use 7 or maybe even 8 depending on whether you can shift the service in one direction by 30 minutes without messing up pathing and coordination with other services.
Sure, but there are two answers to that particular route:
The immediate solution is AC/battery/diesel trimode. In diesel/battery mode the experience from 802207 is that fuel consumption is reduced by 30-50%, by using regenerative braking and running the smaller diesel engine at a steadier power output. So half the benefit of OHLE with no wires.
The longer term solution is to note that Hull-Gilberdyke carries 7.5tph, which makes it a prime candidate for electrifying, with a much better return on investment than 4tph routes like parts of the MML. There's a list of such places here:
Considering lines that are not yet electrified, what sections carry the most trains per hour (tph)? At this stage I'm only considering timetabled passenger services, and not including freight or ECS/NR movements. Or station throats. I can think of the following: Dore - Sheffield (8 tph, I...
You wouldn't need more crew in any case I don't think. But even so most of these edge cases can be eliminated with a small number of additional track kilometres of electrification.
In that example, your options are: (a) give trains an hour's layover at each end of the route, two extra trains needed, no extra crew needed, or (2) give trains 30 minutes' layover at each end of the route, one extra train needed, likely one extra crew needed because they'll now be sitting around in Scarborough and Sheffield for half an hour.
The immediate solution is AC/battery/diesel trimode. In diesel/battery mode the experience from 802207 is that fuel consumption is reduced by 30-50%, by using regenerative braking and running the smaller diesel engine at a steadier power output. So half the benefit of OHLE with no wires.
If we're looking at decarbonisation then diesel bi- or tri-modes should only be considered as stepping stones rather than the end goal, buying time to put in place enough electrification that trains can run fully zero emissions, either off the OHLE/3rd rail or on batteries where there is no electrification. While we might accept diesel as a long-term solution on a handful of very long, low frequency lines (eg West Highland, Far North, Cambrian Coast, Heart of Wales) if hydrogen is not deemed suitable and providing enough power for battery operation is impractical, that has to be very much the exception rather than the rule.
The longer term solution is to note that Hull-Gilberdyke carries 7.5tph, which makes it a prime candidate for electrifying, with a much better return on investment than 4tph routes like parts of the MML.
Agreed, further electrification (even if not full electrification) is going to be essential. Which was kind of my point, even if I didn't spell it out very well!
In that example, your options are: (a) give trains an hour's layover at each end of the route, two extra trains needed, no extra crew needed, or (2) give trains 30 minutes' layover at each end of the route, one extra train needed, likely one extra crew needed because they'll now be sitting around in Scarborough and Sheffield for half an hour.
It is definitely 15MW, 15GW would be impressive (Approx 6 x capacity of Drax). GMRT2111 Rolling Stock Subsystem and Interfaces to AC Energy Subsystem standard generally uses 300A as standard for an OLE section (Single track line) and maximum train current so that is 7.5MW. However in Auto-Transformer land - current will flow both ways to ATs at each end, so you can double that to 15MW. Then once outside the secondary circuit, so between primary feeder and Auto-Transformer, current is halved, so a 300A train will also only apply 150A load.
>300A is used in GB, as well as < 300A, but 300A is the standard.
Extract of guidance from GMRT2111 on how current demand of trains is controlled based on Infrastructure.
Apologies.
I think I miss understood @HSTEd.
I was thinking his 600MW was per diesel train on average so a lot more than 15MW for the line did not make sense.
I rashly thought his 15MW was meant to be 15,000MW (or 15GW).
But I should have realised 600MW is a lot for one train (its more likely 600KW per diesel train).
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It may do in some cases, but the number of diesel routes that spend no significant time on electrified railways is quite small.
Well, in this particular case a handful of electrified track kilometres (I have proposed Dore to Meadowhall) would provide quite a lot of charging time.
Ten minutes Meadowhall to Sheffield, approaching ten minutes layover and then ten minutes back.
You wouldn't need more crew in any case I don't think. But even so most of these edge cases can be eliminated with a small number of additional track kilometres of electrification.
Probably less than the remaining uncommitted track kilometres in the envisaged MML scheme
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15MW per train is about the maximum the copper could take.
The 610MW figure is the average heat output of a fire that consumed all the diesel used on the railway.
Given the efficiency of diesel engines is under 50%, the average amount of power that has to be provided to trains to convert them to batteries will be 200-300MW across the entire system.
Those limits aren't to do with the contact wire though. Those are power supply limitations that can be fixed with limited or no trackside work.
Apologies - I miss understood the 600MW as being larger than the 15MW and jumped to the conclusion that the 15MW must be 15GW. Did not occur to me that 600MW was a hell of a lot for one diesel train !.
Sure, but there are two answers to that particular route:
The immediate solution is AC/battery/diesel trimode. In diesel/battery mode the experience from 802207 is that fuel consumption is reduced by 30-50%, by using regenerative braking and running the smaller diesel engine at a steadier power output. So half the benefit of OHLE with no wires.
The longer term solution is to note that Hull-Gilberdyke carries 7.5tph, which makes it a prime candidate for electrifying, with a much better return on investment than 4tph routes like parts of the MML. There's a list of such places here:
Considering lines that are not yet electrified, what sections carry the most trains per hour (tph)? At this stage I'm only considering timetabled passenger services, and not including freight or ECS/NR movements. Or station throats. I can think of the following: Dore - Sheffield (8 tph, I...
This is the beauty of battery. It means we can cheery pick the best (busiest) sections to electrify without needing it to be continuous for any particular service group. Will have to err on the side of doing too much and my gut feeling is small gaps for the most difficult. That may or may not be ideal as the busiest places are also often the hardest to electrify - large stations. Places with a thin service down some branch or secondary route will be easiest to electrify but will be less benefit due to being the least busy sections !.
Batteries will need replacing far more often than OHLE and they are far from cheap...my car's battery pack replacement cost is £30K so the cost of replacing the traction batteries on a fleet of BEMUs several times over the lifespan of the trains is going to rival that of an OHLE installation
Well that depends on whcih OHLE installation you mean. In current prices, rewiring the GEML was about £400m. That would buy you enough batteries for BEMUs to replace the diesel fleet several times over.
If we say that 50% of the time the train is drawing lots of power for immediate use (probably pessimistic) that would double the amount of line required to be electrified.
This isn’t the csase, as trains aren’t on full power the whole time (just a small fraction) and batteries enable better regen capability. We will need some more power supply, but the amount of electrification needed might be relatively small. A lot depends on freight.
Whilst it's a big mindset shift, IMO with batteries the new norm will be electrification for as short as possible. Whilst electrified lines have a lot of fans on this forum, they have a lot of disadvantages:
Maintanence & repair of OHLE - costly & disruptive to services
Safety - lots of hazards, most common being trespassers killed climbing wagons in sidings
Reliability - services shut down due to fallen trees, trespassers causing power off, drivers e.g. https://www.bbc.co.uk/news/av/uk-england-essex-65653429
Running cost - the longer the wires the more losses to heat
Aesthetics - OHLE (especially with the recent projects) is a blight on the countryside/towns (not everyone has an issue with this)
But the biggest being the astronomical cost & disruption (to railways and roads) of putting it there in the first place.
So why wouldnt you want it to be as short as possible?
You can buy an awful lot of batteries for that. Additionally lithium is a capital expenditure, once the first generation of batteries is procured only limited additional metal is required for later years.
Also wonder if an alternative to OHLE might be developed for stationery charging e.g. 25kv conductor bar between rails (only activating with train above) for a cheaper/simpler/safer alternative to OHLE. E.g. lines where just charging at the terminus is sufficient
Also wonder if an alternative to OHLE might be developed for stationery charging e.g. 25kv conductor bar between rails (only activating with train above) for a cheaper/simpler/safer alternative to OHLE. E.g. lines where just charging at the terminus is sufficient
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