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Hydrogen Trains

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Hydrogen Trains

Old 7th Jan 2019, 15:22
  #21 (permalink)  
 
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It’s no more dangerous than diesel, in fact far less because it dissipates so quickly and you can’t get a sustained fire.
A good definition of a massive explosion
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Old 7th Jan 2019, 15:40
  #22 (permalink)  
 
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Originally Posted by Economics101 View Post
Given that overcrowding and lack of capacity are a huge problem for Britain's railways, reducing 4-car formations to 3-car is just brilliant. Another "failing Grayling" product?
.........itís even worse than you think!

They are reducing the 4 car units down to 3 cars.
But the first and third cars are used for the gas storage tanks, the power unit, control systems and driver cab etc, so according to my maths this leaves just one PAX carriage?
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Old 7th Jan 2019, 17:05
  #23 (permalink)  
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Old 7th Jan 2019, 20:00
  #24 (permalink)  
 
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So how is the hydrogen produced in the first place? Electrolysis of water purely from renewable sources? How efficient is that really?
Also from an engineering arrangement point of view it reminds me somewhat of the Howard Hughes steam car, with condensers in the bodywork. In a prang the occupants would be scolded to death. The principle of using hydrogen as a fuel is basic, but if it really was practical, efficient and SAFE, it would have been done decades ago.
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Old 7th Jan 2019, 21:02
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A common factor with all virtually all mechanically propelled transport is that it requires to carry its fuel on board. Every type of fuel has its own limitations of range, load carrying and safety.

The exception of course are railways (and trams), which are privileged in this respect in that they can avoid the penalties of fuel-carrying by picking up their energy source from electrical conductors along their tracks.

After more than a century of successful electrically powered railways, it seems inexplicable to me that manufacturers and operators should be developing yet another method of carrying quantities of highly volatile fuel on board their vehicles.
​​​
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Old 7th Jan 2019, 21:19
  #26 (permalink)  
 
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Originally Posted by ORAC View Post
Itís no more dangerous than diesel, in fact far less because it dissipates so quickly and you canít get a sustained fire.

https://hydrogen.wsu.edu/2017/03/17/...hydrogen-fuel/
ORAC, the problem is that, in order to contain a significant quantity of H2, it needs to be either under extreme pressure or in liquid form. Rupture that container and you're going to have an explosion before it even catches fire.
Despite what you sometimes see in the movies, diesel doesn't lend itself to explosions.
But the big problem with using hydrogen as a fuel is obtaining it. Electrolysis is horribly inefficient - currently the cheapest and easiest way to create large quantities of H2 is to strip it off from natural gas. So it's still a non-renewable fuel source, and you still have large quantities of carbon to deal with. It makes more sense to simply power the trains with natural gas (currently done with buses in many places).
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Old 8th Jan 2019, 00:40
  #27 (permalink)  
 
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According to my calculations, a 4-car train could also be pulled by... 48 horses. ✅

Or.... a coal powered steam-engine. 😆
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Old 8th Jan 2019, 08:37
  #28 (permalink)  

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The emissions from horses were a major environmental problem in the past.
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Old 8th Jan 2019, 08:55
  #29 (permalink)  
 
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After more than a century of successful electrically powered railways, it seems inexplicable to me that manufacturers and operators should be developing yet another method of carrying quantities of highly volatile fuel on board their vehicles.
The problem with the British railways are that they were built before electric trains were thought of. The height limit or gauge for bridges and tunnels means that there is little room for overhead wires and you cannot have a third rail in the countryside.

It is easy for the Continentals. There had a higher gauge plus the advantage of most of it being replaced after two wars.
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Old 8th Jan 2019, 09:16
  #30 (permalink)  
 
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Ammonia (NH3) is an emerging source of hydrogen and contains more energy than liquid hydrogen for an equivalent volume.
https://publications.csiro.au/rpr/pu...csiro:EP172829
https://blog.csiro.au/hyper-for-hydr...bon-free-fuel/

Hydrogen can either be combusted the normal way in existing internal combustion engines or it can be used to generate electricity using hydrogen fuel-cell technology.

Although ammonia itself is nasty stuff it should be able to be safely handled in much the same way as petrol or diesel.

Now if there is a train collision, the accident scene should come up nice and clean.
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Old 8th Jan 2019, 09:31
  #31 (permalink)  
 
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Originally Posted by Fareastdriver View Post
The problem with the British railways are that they were built before electric trains were thought of. The height limit or gauge for bridges and tunnels means that there is little room for overhead wires and you cannot have a third rail in the countryside.
What's the problem with trains having third rail conductors and retractable pantographs? There are fewer bridges in the countryside, and the 100 billion squandered on HS2 would pay for many to be rebuilt.
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Old 8th Jan 2019, 21:41
  #32 (permalink)  
 
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Originally Posted by Private jet View Post
The principle of using hydrogen as a fuel is basic, but if it really was practical, efficient and SAFE, it would have been done decades ago.
You have to wonder how Karl Benz might have responded to such retrogressive tripe.
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Old 9th Jan 2019, 01:12
  #33 (permalink)  
 
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Originally Posted by cattletruck View Post
Ammonia (NH3) is an emerging source of hydrogen and contains more energy than liquid hydrogen for an equivalent volume.
https://publications.csiro.au/rpr/pu...csiro:EP172829
https://blog.csiro.au/hyper-for-hydr...bon-free-fuel/

Hydrogen can either be combusted the normal way in existing internal combustion engines or it can be used to generate electricity using hydrogen fuel-cell technology.
But you still have the issue of where do you obtain the hydrogen to make the ammonia? Currently, most ammonia is made using natural gas as the hydrogen source since it's far and away the cheapest was to obtain the H2.
Currently the only truly renewable source of the base hydrogen is electrolysis. ( and that's assuming you use electricity from a renewable source). But it's still horribly inefficient to do so. Much better to just use the electricity directly (e.g. batteries). We'll never have a true hydrogen economy until someone solves the problem of creating the hydrogen in a renewable manner.
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Old 9th Jan 2019, 02:25
  #34 (permalink)  
 
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Ammonia (gas) is a by-product of numerous industrial processes .
In some cases it is converted to ammonium sulphate for fertiliser, etc but in many cases it is simply flashed to atmosphere.
I doubt that there would be enough to run a train network though.
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Old 10th Jan 2019, 12:24
  #35 (permalink)  
 
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The elephant in the room here is the dreadful mess Network Rail has made of the electrification programme in the last few years, leading to massive cuts in the ambition to extend the wires (e.g. Midland Mainline to Leicester and beyond, Cardiff to Swansea....). So DfT is rightly reluctant to commit to more wires until NR can prove it knows what it's doing, but on the other hand it has set its sights on abolition of diesel, which leaves them scrabbling around for other solutions. The only logical solution is to put someone in charge of the wiring programme that knows what they're doing. As a parallel this summer I found a brand new hybrid Calmac ferry chugging merrily back and forth across a loch on diesel power - apparently the batteries were good for one or round trips rather than a full daily duty cycle, so the whole exercise appears to have been political. I understand the new generation of Norwegian fjord-hoppers will be battery-only, but will recharge wirelessly via induction loops on every turnround, which sounds a bit more sensible,
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Old 10th Jan 2019, 19:07
  #36 (permalink)  
 
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Sallyann
This article https://www.railjournal.com/in_depth...-third-rail-dc gives a pretty good indication why you wouldn’t use 3rd rail for long distance high speed trains. Max 160km/h and substations at 2-3 km intervals for a start...
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Old 10th Jan 2019, 20:11
  #37 (permalink)  
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Originally Posted by Andrewgr2 View Post
substations at 2-3 km intervals for a start...
I believe that was what helped decide the adoption of AC instead of DC in the USA - although clever marketing by George Westinghouse (with help from Nikola Tesla) over Thomas Edison helped).
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Old 10th Jan 2019, 20:12
  #38 (permalink)  
 
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Originally Posted by Andrewgr2 View Post
Sallyann
This article https://www.railjournal.com/in_depth...-third-rail-dc gives a pretty good indication why you wouldnít use 3rd rail for long distance high speed trains. Max 160km/h and substations at 2-3 km intervals for a start...
Yep. That's why I said use overhead for the rural sections . Not an expert on railways but I've seen trains on Southern with pantographs dropped to roof level.
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Old 10th Jan 2019, 21:58
  #39 (permalink)  
 
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Already in use up here as an alternative to mains electricity when the ferries are alongside in Kirkwall
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Old 11th Jan 2019, 15:07
  #40 (permalink)  
 
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Originally Posted by Sallyann1234 View Post
Yep. That's why I said use overhead for the rural sections . Not an expert on railways but I've seen trains on Southern with pantographs dropped to roof level.
I could be out of date, but Southern was/is third rail DC and anything with a pantograph would be a dual-voltage job as used on Thameslink where they need overhead AC when north of London. Pantographs are worn folded when not in use, as when running on third rail.
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