Bionic Duckweed Rears its ugly head again

[Bald Rick]

How often are people actually stuck on the tube to make it worthwhile to pay for the capital cost and power cost of hauling a couple of tonnes of battery on every train?

On the tube - rarely, on a mainline train - more often (much more out there to damage the current equipment). But it wouldn’t just be for that. It could be for depot moves and getting through short isolations.

 

[edwin_m]

How often are people actually stuck on the tube to make it worthwhile to pay for the capital cost and power cost of hauling a couple of tonnes of battery on every train?

A new Metro today has a lot of safety measures like evacuation walkways that most of the Underground doesn't, and its older systems make evacuation more likely as well as more hazardous. If all those infrastructure measures are justified if building a new Metro, then a battery to get you to the next station is probably going to be considered reasonably practicable on the Underground before too long and therefore justified on safety grounds. Aren't they planned for the Piccadilly line stock?

The same may well apply for somewhere like Thameslink.

 

[Domh245]

Aren't they planned for the Piccadilly line stock?

I think people suggested that they do this, but they've decided to use the precious little underfloor space they have for Air Conditioning instead

 

[Irascible]

I think people suggested that they do this, but they've decided to use the precious little underfloor space they have for Air Conditioning instead

Which itself is something of a candidate for battery backup - being stuck in a tunnel for 30 mins due to signal failure is ok if a bit uncomfortable with the train powered up, being stuck in a tunnel for 30 mins due to power failure ( how often does that happen? I seem to remember one instance in the decade I lived there ) with no air circulation is getting iffy. Gets very hot very fast down there, and there's no pool of air to mix with the exhaust of a few hundred people because there's no real volume between the train & tunnel. But, then again, very rare, rare enough that I think evacuating even via the track is an option. Given, y'know, it's not powered anyway...

 

[DerekC]

Indeed. A 200kw battery pack weighing about a ton would be very useful for a ‘get you out of jail’ use - it would give a four car unit about half an hour at reduced speed. More than enough.

Could I raise one of my pet moans. Energy (as in battery packs) is measured in kWh (kilowatt hours). Power (as in motors) is measured in kW (kilowatts). Most journalists don't know the difference but we should try to set a good example!

I guess in this case we are talking about a 200kWh battery pack. A four car EMU might typically have an installed power of about 1500kW so a pack that size would give very roughly 25% power for half an hour. Sounds about right for a trundle at 30-40mph. For comparison the IPEMU (Independently Powered EMU) prototype trialled by RSSB, Network Rail and Bombardier had a 423kWh battery pack for a specified range of about 50km at a maximum in-service speed of 60 mph.

 

[GRALISTAIR]

Power is the rate of using energy - simply.

1 watt of power = 1 joule per second.

 

[edwin_m]

Power is the rate of using energy - simply.

1 watt of power = 1 Joule per second.

So a kilowatt hour is 3.6 million joules. And SI units should take a small initial letter when spelt out in full but referring to the unit not the person it was named after - something the originator of bionic duckweed regularly gets wrong...

 

[GRALISTAIR]

So a kilowatt hour is 3.6 million joules. And SI units should take a small initial letter when spelt out in full but referring to the unit not the person it was named after - something the originator of bionic duckweed regularly gets wrong...

Duly noted and corrected thank you. I am embarrassed I use scientific units all the time believe it or not! Though calories are used more in the USA.

 

[Philip Phlopp]

Though calories are used more in the USA.

Not used as much as they're consumed, alas...

== Doublepost prevention - post automatically merged: 16 Nov 2020 ==

Or you just do what happens now, and use that power to boil kettles, run TVs, run factories etc.
Energy storage has a place, but there's no reason it needs to be directly connected to railway catenary.

On your second point, 25kV isn't the best choice for long distance power balancing, and it would be complicated by the fact there will still be some trains running, with a very peaky power demand. I also don't think the ECML, for example is a single circuit all the way from London to Edinburgh, it's a lot of much smaller sections separated by neutral sections.
It's designed so that feeder station feeds a single section, so by definition it's useless for moving power around the country.
I'm puzzled as to why we need some sort of not very good duplicate for the National Grid?

The logical place to locate batteries or other energy storage is near to very large renewable. It can already be moved wherever it's required by the grid, railway electrification schemes are designed for powering trains, not duplicating the grid.

25kV isn't the best choice for any sort of power balancing - but (and I'm ignoring static frequency converters because they uncomplicate things enormously in many useful ways) the feeding arrangements for conventional 25kV being spread across different phases of the HV energy supply and the need to balance load across all phases means shuffling power around using the 25kV OLE and storing power just off the OLE could potentially be useful developments in providing feeding in areas where no HV feeding supply is available, or where balancing the phases with existing feeders is sub-optimal.

 

[Bald Rick]

Could I raise one of my pet moans. Energy (as in battery packs) is measured in kWh (kilowatt hours). Power (as in motors) is measured in kW (kilowatts). Most journalists don't know the difference but we should try to set a good example!

I guess in this case we are talking about a 200kWh battery pack. A four car EMU might typically have an installed power of about 1500kW so a pack that size would give very roughly 25% power for half an hour. Sounds about right for a trundle at 30-40mph. For comparison the IPEMU (Independently Powered EMU) prototype trialled by RSSB, Network Rail and Bombardier had a 423kWh battery pack for a specified range of about 50km at a maximum in-service speed of 60 mph.

My apologies; I did know it was kWh, my only defence is that I was almost asleep when typing that!

A 4 car class 377 has 1.2MW under the bonnet, so 200kwh gives you half power for 20 mins. But I’d be willing to bet that a 377 on constant half power would reach linespeed on most routes relatively quickly, and on all but a handful of duties there would be coasting / braking which is drawing no power for traction, so half an hour at something like a normal duty cycle would be probable.

(Hence why a 1MWh battery would get you from Hurst Green to Uckfield and back, but that’s another thread)

 

[gallafent]

East-West Rail …

is not open[1] yet

[1] Marston Vale …
[2] Oxford – Bicester?

 

[GRALISTAIR]

And now we have de Pfeffel’s 10 point plan

 

[Bikeman78]

But yet we've got East West Rail which has not acquired any rolling stock yet and is not open[1] yet, and so those things wouldn't cause any problems for anyone if it was to be electrified before opening, and would have many benefits to doing so. I did think the reason for not being bothered about it was because of the early proposal for it to be run through to/from Marylebone which would have to be DMUs, but that has long since gone away (and applied only to one of the proposed three trains per hour anyway). It's absolutely nuts that we are building a self-contained railway to be diesel in 2020.

[1] Except of course the Marston Vale, but only about 4 or 5 people would notice if that was closed for a while

I agree. If there's any chance of it being electrified in the next 20 years then it might as well be done now. Avoids the hassle of closing the line in a few years. The cost of electrification is only likely to go up with the passing of time owing to more and more strict H&S standards.

 

[Philip Phlopp]

I agree. If there's any chance of it being electrified in the next 20 years then it might as well be done now. Avoids the hassle of closing the line in a few years. The cost of electrification is only likely to go up with the passing of time owing to more and more strict H&S standards.

It'll not get more expensive that it got for the GWEP, a few bits of the EGIP and GOBLIN. Much work done to make it less expensive and no real risk of H&S becoming more draconian than it is already, in fact, better risk assessment and analysis is likely to reduce H&S requirements.

But it's better to electrify when there's no track down - the French put in the masts, cantilevers and some of the wiring before the track goes down, when they're building their HS routes.

 

[ABB125]

It'll not get more expensive that it got for the GWEP, a few bits of the EGIP and GOBLIN. Much work done to make it less expensive and no real risk of H&S becoming more draconian than it is already, in fact, better risk assessment and analysis is likely to reduce H&S requirements.

But it's better to electrify when there's no track down - the French put in the masts, cantilevers and some of the wiring before the track goes down, when they're building their HS routes.

Out of interest, why's it better to stick up the masts before the track goes down? The only thing I can think of is slightly more flat space being available for machinery?

 

[Domh245]

Out of interest, why's it better to stick up the masts before the track goes down? The only thing I can think of is slightly more flat space being available for machinery?

Mostly because it's a lot easier to build things when it's on a field than when it's on a railway

 

[hwl]

Out of interest, why's it better to stick up the masts before the track goes down? The only thing I can think of is slightly more flat space being available for machinery?

and you can also use conventional construction equipment rather than RRVs which is cheaper.

 

[ABB125]

Mostly because it's a lot easier to build things when it's on a field than when it's on a railway

and you can also use conventional construction equipment rather than RRVs which is cheaper.

That makes sense, thanks.

 

[hwl]

That makes sense, thanks.

Site logistics are is also easier with out track as you can just drive around anything in the way. There needs to be far less coordination and planning.

But RRV based equipment has been getting far more useful recently so possibly the gaps should be reducing

 

[Domh245]

Site logistics are is also easier with out track as you can just drive around anything in the way. There needs to be far less coordination and planning.

Just to expand on that (and my earlier post) - not only is the on-site logistics and coordination less, but also you've got near enough 24h access to the site and can use workers with less specialist training. No need to work around (and pay compensation for disrupting) a timetable, or paying high rates to workers for working weekends and nights, you're able to just get any contractor to stick some masts in the ground during a normal day shift

 

[hwl]

Just to expand on that (and my earlier post) - not only is the on-site logistics and coordination less, but also you've got near enough 24h access to the site and can use workers with less specialist training. No need to work around (and pay compensation for disrupting) a timetable, or paying high rates to workers for working weekends and nights, you're able to just get any contractor to stick some masts in the ground during a normal day shift

I though the original question was just focused around new lines before they open to traffic and the advantages of masts before tracks in that case, operation lines are a whole world of extra work beyond that...

 

[edwin_m]

I would have thought it was easier to lay the track first. A lot of OLE plant is track-mounted so having the track there may actually help, but having the OLE there when you're trying to lay the track certainly doesn't help and may get in the way.

 

[Elecman]

I would suggest putting the mast foundations in first, then the track and then finally the steelwork and wires from a works train

 

[Philip Phlopp]

I would have thought it was easier to lay the track first. A lot of OLE plant is track-mounted so having the track there may actually help, but having the OLE there when you're trying to lay the track certainly doesn't help and may get in the way.

OLE plant which is track-mounted, other than that utterly self defeating HOPS, is typically a road vehicle with some modifications which makes it less good at doing its job than it otherwise could be if it was just a road vehicle. And you can park a road vehicle exactly where you want it when you bore/dig/pile/pour foundations and again when you lift masts into place.

OLE rarely if ever gets in the way of track installation. It's a tad more challenging with our loading gauge of course, but it's not much of an issue.

The usual way of doing it in France, which is the correct way, is to do foundations, mast installation then cantilever installation with those folded back out of the way before track laying occurs. You can also do some wiring pre track laying. Catenary wiring and final registration then takes place once the track is present against which the catenary is 'registered' against though as everything is built/registered to a datum point, rather than existing track in an electrification scheme, you could electrify fully prior to track laying and everything would be very close to being perfect (thought that might be because the French are bloody good at building new railway lines now).

 

[Bald Rick]

The usual way of doing it in France, which is the correct way,

They didn’t lay the track the correct way though, until we showed them how!