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Discussion in 'UK Railway Discussion' started by Stroud Valleys, 16 Sep 2017.
That’s what I’d have thought. Reports of its sudden demise are equally likely to be fact free.
Is it? Any real evidence for that?
Indeed. Even if it needs maintenance, I'm sure it's nothing that can't be fixed (as with the rest of the Southern Region).
I've heard there's a volt-drop problem in places, but that's just loop resistance which might be addressed to an extent by some further welding up of both power and running rails into longer sections. Also a modern solid-state traction system on board the trains might be more tolerant of voltage variability if so designed. Add a SMALL battery on each train and there would be temporary storage to collect and re-use braking energy without re-equipping substations, boosting acceleration anywhere volt drop is a problem, trickle charging elsewhere when coasting and there is spare supply capacity available. Substation equipment is no doubt getting on but it's small scale stuff on the island compared to the mainland system, 'small industry' size rather than 'super factory' needing a grid connection, and could be renewed fairy economically if necessary. Charging more continuously from a retained third rail would require a smaller peak load than periodic full fast recharging at termini. On board batteries could allow short gaps in the power rail where expedient, along the pier and through Ryde tunnels for example.
That's very interesting. I've never understood the obsession with getting rid of the third rail here.
Me neither, all that talk of hydrogen fuel cell technologies etc replacing electrification doesn’t seem any closer to actual mainstream service than when Alistair Darling used to mention it whilst SOS for transport .
nooo. Confirmation on The the new(ish) 230s being battery powered has been made, I don't know why that is for discussion in a slightly irrelevant subject.
I meant battery power for the Island Line itself is pure speculation. People are trying to push battery power on an electrified railway with no justification. Just like a little while ago they were trying to recommend diesel 230s for Romford to Upminster.
Ok well. I wouldn't think it would be too hard since all you would need is like a battery charging station if you know what I mean
It would have to be more powerful than the electrification that’s already there.
I wonder what work, if any, would be needed to convert the D-stock trains from 4th rail operation to 3rd rail operation?
I would imagine not at all difficult (certainly when compared to turning one into a DMU), would just presumably be a case of removing the 4th rail shoe and bonding the return to the wheels, plus suitable insulation where required.
But isn't the electrification knackered?
Fit axle end mounted current return brushes, and wiring to suit. Probably all to be done on the bogies. They have already worked on the 630V dc on the Wimbledon branch, with return via the 0V fourth rail. Potentially the easiest modification you could make, compared to battery or diesel.
No real evidence for that is there, other than speculative posts here? If it was ‘knackered’ how do the trains run now?
I remember over 15 years ago a member of the public at Smallbrook Junction claiming the substation near Sandown needed replacement. If the infrastructure is knackered it's been knackered for a while.
technically not difficult,given the power drops in the line.
having a short stretch of live rail at each terminus is quite sufficient,even with existing gear.
I suspect they would uprate to 750v anyway,and do a blue peter job with some hand-me-down southern equipment.
Yup, it's been pretty poor for a long time - remember the service is somewhat less intensive than it was when electrification was first introduced. On summer Saturdays, there were six seven-car trains in service for the first year or two, and the equipment was designed to cope with that, but it's now over fifty years old and serious voltage drop at the south end of the line has been a problem for years, even with shorter and less frequent trains.
Given how much battery technology has advanced, how much new substations cost, and how much money Island Line loses, the solution adopted needs to be as cost-effective as possible, and I reckon battery technology is a no-brainer here.
Remember that electrification is usually only carried out when there's a good business case for it, and for quite some time in the sixties the idea was to convert the Standard Stock to diesel operation for the island. It's only when that plan hit problems that the decision to electrify was made. The number of people using the railway on the island has dropped sharply in recent years and just about every single item of equipment is falling to pieces, so it's going to cost a lot to get things back to decent condition. I'd say stripping out the old electrification equipment and replacing it with a couple of charging points is going to boost the viability of improvements considerably.
A 230 with a battery could run on the 3rd rail and use the battery to boost power when there is a voltage drop and use it for faster acceleration / speeds deferring any issue with the current system. It is not to replace what is there, just to defer costs.
Couldn't that be more expensive though, in that you're maintaining both a third-rail, and an extra battery system in the train?
It strikes me it would be better (and probably cheaper) to concentrate on one system, and spend the money to make it work properly.
For the low usage, it would surely make economic sense to have bits of third rail at some stations to recharge a battery rather than keep third rail throughout which, remember, has a cost to maintain - electrification is not 'free' and any maintenance cost is going to be higher on the IoW because you can't benefit from economy of scale like you can with a third rail network on the mainland i.e. continuous use of heavy plant and large teams of workers that can be used efficiently across many routes.
The battery capacity which was being talked about suggested a round trip would be possible on a single charge - that would logically mean keeping some charging capability at Shanklin and Ryde St Johns - whether it needs to be a third rail is an interesting question as Vivarail might have some other options in mind.
Yep, I'd read about that but didn't want to seem too specific, though only maintaining recharging capacity at each end would certainly cheapen things further versus maintaining third rail across the entire line with all the constraints that entails (maintenance and preventing voltage drop etc.)
It'd have to allow a round trip, as putting charging facilities on the pier is probably a non-starter, so most probably it'll have to be Shanklin and the depot.
I'm not up on the ins and outs of battery trains. What happens if one gets stuck between stations for a couple of hours (tree needs removing from the line etc.). If the heating's blasting away, doesn't that drain the battery? Are these 230s capable of pushing/dragging one another back to the charging point in this case? Or will a diesel 'Thunderbird' be needed?
Depends how heating is done - our local electric buses actually have diesel-fired Webasto heaters!
You get a variety of approaches, in Switzerland the funiculars often have storage heaters which are only powered when on the juice to charge. That approach would likely work too.
that would make sense.
maybe have the heating run through a giant immersion heater and water tank...that way the residual heat keeps going for hours, just like your average domestic central heating system.
That way, if there is a blockage on an unpowered section of line,all you are powering is the pumps and the fans.
But why get rid of the 3rd rail itself? That is a very low maintenance asset in itself and is not getting worn out particularly quickly with the traffic level on the island. There should also be plenty of second hand spare conductor available for future renewal from the mainland. The substation assets are presumably as old as the original electrification itself, so might justify renewal at some point, but as I said before it is all relatively small scale compared to main line equipment so in capital terms should be fairly cheap to renew. The rating of such equipment should actually be significantly lower than fast charging equipment confined to terminals, and that would also apply to the rating of the supply from the local distributor, unless such charging points also include significant storage of their own to limit peak draw at charging events. Batteries on board the new rolling stock, if only having to cope with limited discontinuity in the 3rd rail rather than complete absence, can normally charge more slowly so should last longer. Discontinuous electrification is the option chosen for the South Wales tram-trains, albeit with OHLE at 25kVAC, but the principle is the same. Small batteries on board electric trains have other benefits such as get out of trouble and 'hotel' power in event of partial supply failure and removal of third rail from the depot area (for safety).
Would that have implications for the timetable, since that would imply the train would need to sit at the terminus long enough to recharge (plus the usual allowance for late trains to catch up time)? At present, trains are scheduled to wait at Shanklin about 5 to 8 minutes, and a similar time at Ryde Pier Head (where as Bletchleyite notes, charging may not be possible).
Hypothetically, if the Island Line is expanded in the future, what current obstacles would the railway have to overcome and where would any diversions go:
Shanklin to Ventnor (except for the obvious difficulties with the tunnel and old station site in Ventnor)
Sandown to Newport
Newport to Cowes
Newport to Freshwater
Wootton to Newport
Money - lack of
Money - value for