What are the cons for running trains on Gas Turbines vs 25kv wires

[richieb1971]

Reading about the APT-E, if such high speeds were attainable in 1972 why not try again today with the same tech?

I mean, this thing did 152mph on non wired track. And since that time no other train manufacturer has dabbled in it (to my knowledge).

Its got to be relatively carbon free and it doesn't need wires to run all over the network.

 

[Domh245]

Compared to electrification, gas turbines lack the ability: to localise (or even completely get rid of) emissions, to provide regenerative braking, and they take up additional space onboard. They have much the same sort of advantages and disadvantages compared to electrification as a Diesel powered train.

So it then boils down to Diesel v Gas Turbine. The Gas turbine generally has a better power to weight ratio, requires less lubrication, and is physically smaller than an equivalent ICE. However, they only work well at a narrow range of speeds and loads and aren't very good elsewhere, which makes them fairly good for boats and power stations where it'll be operating at optimum parameters for days on end, but not good for trains where it has to keep on jumping around for every PSR, restrictive signal aspect, etc. Additionally, all the space saved by having a smaller power unit would be quickly lost to the increased space needed to store the fuel, and not to mention that a gas turbine is going to be far more expensive than an equivalent powered Diesel engine.

I'm also doubtful as to whether or not a gas turbine emits less CO2 than a diesel engine, I can't see anything authoritative, but I can see sources that suggest about 250 to 300gCO2eq/kWh for diesel vs 400 to 500gCO2eq/kWh for Gas turbines. You probably get fewer other pollutants (NOx and other particulates) out of a gas turbine.

 

[superkev]

Gas turbines are only really efficient at high loads where railway use engines spend a lot of time idling then upto full power for short bursts. Nothing like as efficient as a diesel.
The French among others had some gas turbine trains I believe.
K

 

[Xenophon PCDGS]

In historical terms, there were two gas turbine prototype locomotives, 18000 and 18100, which were produced in the middle years of the last century.

 

[Tracked]

In historical terms, there were two gas turbine prototype locomotives, 18000 and 18100, which were produced in the middle years of the last century.

and GT3, a bit later:
https://en.wikipedia.org/wiki/British_Rail_GT3

 

[EM2]

Gas turbines are only really efficient at high loads where railway use engines spend a lot of time idling then upto full power for short bursts. Nothing like as efficient as a diesel.
The French among others had some gas turbine trains I believe.
K

This is correct. The Union Pacific Railroad in the US had some gas turbine locos and found that they used almost as much fuel at idle as they did at full power.

 

[jopsuk]

what truly killed the APT-E and the French Turbo Trains (including TGV001) was the 1973 Oil Crisis

 

[Billy A]

The French used several varieties of the Turbo Train which Wiki will tell you all about. They had a pair of helicopter gas turbines but turned out to be far too thirsty so they got the bright idea of replacing one of the engines with a bigger and thirstier one. Why? Because they could then use both units to get up to speed and then turn off the smaller one. There's a video on you tube showing the starting sequence and you can see the rev counter going around several times as the turbines spool up...
They were in use for thirty odd years.

 

[daikilo]

The French used several varieties of the Turbo Train which Wiki will tell you all about. They had a pair of helicopter gas turbines but turned out to be far too thirsty so they got the bright idea of replacing one of the engines with a bigger and thirstier one. Why? Because they could then use both units to get up to speed and then turn off the smaller one. There's a video on you tube showing the starting sequence and you can see the rev counter going around several times as the turbines spool up...
They were in use for thirty odd years.

And Bombardier borrowed one as a prototype for their JetTrain, using an aircraft engine (PW150), which Bombardier claimed would be more efficient than a diesel, in part at least due to the lower weight of the powerplant.

 

[RichmondCommu]

The French used several varieties of the Turbo Train which Wiki will tell you all about. They had a pair of helicopter gas turbines but turned out to be far too thirsty so they got the bright idea of replacing one of the engines with a bigger and thirstier one. Why? Because they could then use both units to get up to speed and then turn off the smaller one. There's a video on you tube showing the starting sequence and you can see the rev counter going around several times as the turbines spool up...
They were in use for thirty odd years.

From memory they operated out of Gare du Nord and had a yellow (ish) livery.

 

[najaB]

As others have said, gas turbine engines are at their most efficient running at pretty constant high RPM which doesn't match the power demands of a train. So the best use would be a small gas turbine charging a large(ish) battery bank. In normal operation the turbine would provide motive power, with the battery pack supplementing it when power needs are the highest.

However, you're now lugging around fuel, batteries and a turbine so it might be a wash from a weight point of view as compared to carrying fuel and a larger diesel engine.

 

[edwin_m]

From memory they operated out of Gare du Nord and had a yellow (ish) livery.

Orangey with chrome bits I think. When camping in Normandy in 1976 my 11th birthday treat was my dad taking me on one for a day trip to Paris from either Trouville-Deauville or Dives-Cabourg. So they were definitely running out of St Lazare at that time. I believe they were later transferred to some hilly non-electrified cross-country route further south.

 

[fireftrm]

Plus VERY definitely not 'virtually carbon free' as they burn fossil fuels - basically they are jet engines driving mechanical, or electrical machines

 

[Kentish Paul]

From memory they operated out of Gare du Nord and had a yellow (ish) livery.

Indeed. Travelled from Dover to Paris in 1988 or 89 for a long weekend.
SRN4 hovercraft to Boulogne and then Turbotrain to Gare du Nord. There was a station at the hoverport called Boulogne Aeroglisseur purely for the hovercraft.
Gas turbines all the way from Dover to Paris.

 

[najaB]

Plus VERY definitely not 'virtually carbon free' as they burn fossil fuels...

Well, hydrocarbon fuel. It doesn't have to be from petroleum sources.

 

[rf_ioliver]

I believe they were later transferred to some hilly non-electrified cross-country route further south.

IIRC they ended their days on the cross-country Bordeaux-Lyon route a few years ago.

Great looking and sounding trains!

t,

Ian

 

[AnonymousUser1]

Well, hydrocarbon fuel. It doesn't have to be from petroleum sources.

indeed but the waste product of burning the relevant fuel is still CO2, water, nitrogen oxides and whatever other nasties ...

the use of biomass isn;t necessarily any better at the tail pipe, the carbon reduction comes from growing the plants to provide the fuel

 

[Billy A]

Their last trip in France was Dec 2004 on the Lyons- Bordeaux route by which time only a few were left. They were replaced by loco hauled trains which increased the journey time by an hour or so, partially because they had to change direction repeatedly. Interestingly the last five were sold to Iran (and hauled there by rail!) to join three that the Iranians had bought previously. They were eventually converted to diesel.

Egypt has a few as well which are apparently still in use.

 

[InTheEastMids]

Indeed. Travelled from Dover to Paris in 1988 or 89 for a long weekend.
SRN4 hovercraft to Boulogne and then Turbotrain to Gare du Nord. There was a station at the hoverport called Boulogne Aeroglisseur purely for the hovercraft.
Gas turbines all the way from Dover to Paris.

Sorry, turned right off Topic and am heading down Memory Lane...

I did a Paris on the same hovercraft route and then had a turbotrain down to Paris. Think that was the time we stood in the guard's compartment of the 310 to Euston, because only a 4-car arrived with one carriage out of use. Then onto a filthy, decrepit Southern electric to Dover Western Docks. Oh, and the hovercraft was biblically noisy and smelt of sick, and bounced unpleasantly off the crests of the wave. Terrible

I think it was my first trip on a train outside the UK, and it was like a different world - so smooth, comfortable, spacious and clean. I thought it was wonderful, and if it were a choice between renewable powered 1980s SR EMUs and Turbotrains running on tar sands and Trump rhetoric, well frankly the planet can just boil

But yes the main advantage of a GT is high power:weight. High electrical efficiency is only really possible with continuous running provided a steam cycle is bolted to the back as in marine or large-scale power generation - which is hard to do on a train, and much easier if you put the GT on the ground next to the railway and send the power to the train using some kind of wire-based system

 

[Bletchleyite]

Gas turbines are only really efficient at high loads where railway use engines spend a lot of time idling then upto full power for short bursts.

These days they could of course be used to charge a battery so able to run at full efficiency.

 

[jopsuk]

These days they could of course be used to charge a battery so able to run at full efficiency.

Jaguar had the most recent working concept car to use that system. Never made it into production

 

[AnonymousUser1]

These days they could of course be used to charge a battery so able to run at full efficiency.

i think a series hybrid GT / Battery electric is the most likely implementation we'll see in road vehicles and /or trains , a lot depends on battery/ capacitor technology though as their energy density and mass to energy ratios are still an issue compared to 'burnable' oils whether petroleum or veg.

 

[edwin_m]

There was an experimental tram fitted with gas turbine and supercapacitor energy storage - Google for the ULEV-TAP project. Nothing came of it as far as I know.