Running costs: HST vs Voyager

[transmanche]

It's often stated on here that Voyagers are expensive to run because they are not fuel efficient (sometime described as 'thirsty' or 'diesel addicted'!). The same is said for the 185s. But just how much fuel do they use - and how does that stack up against total operating costs.?

I've tried Googling (and a site-specific search here) but not come up with anything concrete.

Leaving aside staffing and other ancillary costs. The variable track access charges are fairly easy to work out:

• A 4-car 220 costs 34.88p per mile - so a double Voyager is 69.76p per mile.
• An 2+7 HST costs 102.07p per mile.

(I'm assuming they have roughly the same passenger capacity.)
For the record; a 185 costs 37.59p per mile, so a double unit costs 75.18p per mile.

Source: http://www.networkrail.co.uk/browse...harges/b - track usage price list for cp4.pdf

So the Voyager wins out on lower track access charges, but I'm guessing from what I see in others' posts that fuel is a far more significant cost than Track Access Charges.

Engine power might give an indication of how much fuel they use.

• HST 2 x 2,250hp = 4,500hp
• 220 4 x 750hp = 3,000hp - or 6,000hp for a double Voyager
• 185 3 x 750p = 2,250hp - or 4,500hp for a double unit

Now we know that a 185 only needs all that power for acceleration and hill-climbing. They often operate in 'eco-mode' with only 1,500hp per unit (so 3,000hp for a double unit). I'm guessing something similar is true for the Voyager, that they only need all the power for acceleration, hill climbing and 125mph running. So do they have a similar 'eco mode' where certain engines can be switched off/left to idle? Or do they just run at lower revs, to generate less power when not so much is needed? Surely they're using less fuel if they're not using all the power of all the engines?

I'm not a mechanic or engineer - so much of the above may be irrelevant. But I'd really like to get to the bottom of understanding just how much fuel the three types of unit use, on a comparable run.

 

[HSTEd]

A Class 220 supposedly consumes something like 0.54L/vehicle kilometre of diesel. So 8 cars would consume ~4.3L/km.
A 2+7 HST consumes ~4.6L of diesel per km. (Both figures derived from the RSSB 'Traction Energy Metrics' report).

Voyagers drinking fuel is just an argument trotted out by people who like to peddle that "DMUs inefficient beyond five cars" thing.
While a Class 220 is far more powerful it can shut down engines when it doesn't need them, erasing the "overpower" issues.

 

[Metrailway]

Class 43 + 8 Mk3 + Class 43 = 0.89 litres/100 seat km

Class 220 = 1.42 litres/100 seat km

 

[Royston Vasey]

A Class 220 supposedly consumes something like 0.54L/vehicle kilometre of diesel. So 8 cars would consume ~4.3L/km.
A 2+7 HST consumes ~4.6L of diesel per km. (Both figures derived from the RSSB 'Traction Energy Metrics' report).

Voyagers drinking fuel is just an argument trotted out by people who like to peddle that "DMUs inefficient beyond five cars" thing.
While a Class 220 is far more powerful it can shut down engines when it doesn't need them, erasing the "overpower" issues.

Given that an HST is a DMU that argument would still hold, surely? (Or if you insist, a generous two type 4 locos on 7-8 coaches) How would a Class 67 plus 8 x Mk3 compare, for the sake of argument?

 

[HSTEd]

Given that an HST is a DMU that argument would still hold, surely? (Or if you insist, a generous two type 4 locos on 7-8 coaches) How would a Class 67 plus 8 x Mk3 compare, for the sake of argument?

You might get a slight improvement but nothing to write home about.
HSTs are essentially fixed formation loco hauled trains in every way that matters.


And the reason the consumption per seat kilometre of a Voyager is so high is simply because of the terrible internal layout.
And its not really fair to compare a 4-car multiple unit with a train that is 220m long.

 

[transmanche]

Thanks to HSTEd for the info about the report.

Class 43 + 8 Mk3 + Class 43 = 0.89 litres/100 seat km

Class 220 = 1.42 litres/100 seat km

Hmm, a bit of selective presentation there? I note the RSSB report itself queries that figure and uses 1.20 litres/100 seat km in the tables for both 220 & 221s and 0.98 litres/100 seat km for a 9-car 222.

I see that the HST simulation was based on an ECML run, so not a direct like-for-like with the Voyagers. And I also note that the whole report dates from 2007 - so may not be indicative of the TOCs current driving policies.

So an interesting report - not really conclusive one way or the other. But nothing like the figures I expected to see - based on opinions posted here, I was half expecting Voyager fuel usage to be 3-4 times an HST!

 

[Metrailway]

Hmm, a bit of selective presentation there? I note the RSSB report itself queries that figure and uses 1.20 litres/100 seat km in the tables for both 220 & 221s

Maybe... but I prefer figures from the 'real world' rather than simulations

 

[edwin_m]

Class 43 + 8 Mk3 + Class 43 = 0.89 litres/100 seat km

Class 220 = 1.42 litres/100 seat km

Do you have a link for these please?

 

[JamesRowden]

A Class 220 supposedly consumes something like 0.54L/vehicle kilometre of diesel. So 8 cars would consume ~4.3L/km.
A 2+7 HST consumes ~4.6L of diesel per km. (Both figures derived from the RSSB 'Traction Energy Metrics' report).

Voyagers drinking fuel is just an argument trotted out by people who like to peddle that "DMUs inefficient beyond five cars" thing.
While a Class 220 is far more powerful it can shut down engines when it doesn't need them, erasing the "overpower" issues.

The energy efficiency of a multiple unit will depend on the length of the train. This is because the aerodynamic drag should be almost indepedent of the length of the train. This makes longer Voyager formations more energy efficient per seat. However, the energy required for acceleration per carriage should remain indepedent of train length.

Perhaps Voyager sets being shorter than HSTs has lead to people wrongly assuming that becuase a 4/5 car Voyager requires more energy per set per mile than an HST, that this is completely due to the class of train rather than being possibly significantly due to the length of the train. Although, a Voyager having more power per unit mass (for greater acceleration) will require a geater mass of engines per carriage and so increase the amount of energy required to accelerate up to speed.

 

[Zerothebrake!]

Are these figures taking into account that the Voyager engines have all been derated with one even isolated on a CL 221 for 'fuel saving'?

 

[broadgage]

In the case of a loco hauled or HST formation I would expect that a longer train would be more efficient (per vehicle or per seat) due to the reduced wind drag per vehicle.

Not certain if a double voyager would save much per vehicle as compared to a single one though due to the sloping front ends in the middle adding to drag as compared to a longer train.
Driving cabs also add weight and length, and therefore fuel consumption without adding any passenger space.

If one was, hypotheticly, to build an 8 car train of the voyager design, semi permanently coupled and without intermediate cabs, then I would expect this to show a useful fuel saving per seat over a pair of 4 car units coupled together.
A purpose built 8 car train should have less drag than 2 units each of 4 cars.
A purpose built 8 car train of the same total weight and length as 2 units each of 4 cars should have more than twice the number of seats.

Other factors being equal, I would expect that an 8 car train would be cheaper to build and lease than a pair of 4 car units.

Multiple units have their merits, but if they regularly run long distances at high speeds, in multiple, then a purpose built longer train may be more economic.

 

[notadriver]

This is an excellent document comparing transport modes although results are based on co2 emissions rather than actual fuel consumption.

http://www.rssb.co.uk/SiteCollectio...search/T618_traction-energy-metrics_final.pdf

It can be seen how the Voyagers emit more co2 (and probably use more fuel) than any other diesel unit. The report says that power diesel units such as Voyagers emit more co2 than buses.

 

[asylumxl]

It can be seen how the Voyagers emit more co2 (and probably use more fuel) than any other diesel unit. The report says that power diesel units such as Voyagers emit more co2 than buses.

But it may well be that the engines are run rich to reduce the other particulate emissions. Afterall, CO2 is not the only greenhouse gas.

 

[Yew]

Aye, its a lot more complicated than Co2 being proportional to fuel consumption. Also, are the HST figures for a Valenta, VP185, or MTU?

 

[asylumxl]

Aye, its a lot more complicated than Co2 being proportional to fuel consumption.

Yew are correct.

(I'm sure you've never heard that before)

 

[tbtc]

Voyagers drinking fuel is just an argument trotted out by people who like to peddle that "DMUs inefficient beyond five cars" thing

Agreed

 

[Bob Ames]

http://www.rssb.co.uk/SiteCollectio...search/T618_traction-energy-metrics_final.pdf

Some sobering reading for me, especially given that a) I now spend 18 hours per week on Voyagers, and b) my interest in railways was rejuvenated when I crashed my Prius last year (it had the obligatory Greenpeace stickers and also a nice 'Don't drive diesel' sticker on the back window - what a pious hypocrite!).

 

[junglejames]

Take a look at the efficiency figures for the actual engines (grams per KW). That will give you a very good idea which uses less fuel.

I cant be bothered to check the figures again, but one thing I can remember, the MTUs in the HST is more efficient than the Cummins in the 22x. So if the HST had the same power as an 8 coach voyager, then the HST would be using less fuel. Now take into account that a HST has a lot less power, and the fuel figures for a HST look even better. Now take into account that due to the stupid amount of power on the voyager, it is going to be running nowhere near full power for most of the time. Even further from full power than a HST. That means the efficiency of the voyager gets even worse still, as the engines are usually more efficient the closer to full power you are.

Basically, a HST will be winning hands and feet down.

I know certain voyager lovers insist that this thing about being thirsty is just thrown around by people that arent voyager lovers. But ask anyone in the know, and it is shown to be very very true. 4500hp v 6000hp, with the 6000hp having less efficient engines. There is only one winner.

 

[HSTEd]

And yet the actual consumption figures don't support this.

 

[junglejames]

And yet the actual consumption figures don't support this.

You have managed to come out with figures which nobody else has seen. All figures show voyagers using more fuel, and engine consumption figures support this.

 

[asylumxl]

You have managed to come out with figures which nobody else has seen. All figures show voyagers using more fuel, and engine consumption figures support this.

And yet you've given no source for your figures. Pot and kettle much?

 

[junglejames]

And yet you've given no source for your figures. Pot and kettle much?

As I said. Check out the official fuel consumption figures for the respective engines. I told you what to look for.
The other set of figures, as elluded to by someone else, are in that large energy efficiency report comparing all sorts of different modes of transport (do I really need to provide a link to something already linked?). This brings the HST in ahead of the voyager. So yes, all my figures are out there. HSTed has plucked some figures out of thin air which go against all published figures.

 

[notadriver]

As I said. Check out the official fuel consumption figures for the respective engines. I told you what to look for.
The other set of figures, as elluded to by someone else, are in that large energy efficiency report comparing all sorts of different modes of transport (do I really need to provide a link to something already linked?). This brings the HST in ahead of the voyager. So yes, all my figures are out there. HSTed has plucked some figures out of thin air which go against all published figures.

That was me who quoted the co2 figures. I think its fair to compare similar types of transport and train (ie 125 mph capable main line trains) on that basis. But comparing the co2 emissions of a Megabus coach and a Eurostar train for a journey to say Paris is not fair.

 

[asylumxl]

As I said. Check out the official fuel consumption figures for the respective engines. I told you what to look for.

If you're going to say it then you should provide a link to them.

It's even more ironic when you consider you haven't given any figure, but rather just told us an MTU is more efficient.

 

[HSTEd]

As I said. Check out the official fuel consumption figures for the respective engines. I told you what to look for.
The other set of figures, as elluded to by someone else, are in that large energy efficiency report comparing all sorts of different modes of transport (do I really need to provide a link to something already linked?). This brings the HST in ahead of the voyager. So yes, all my figures are out there. HSTed has plucked some figures out of thin air which go against all published figures.

According to the RSSB 'Traction Energy Metrics' report the 9-car Meridian (which is what a Class 220 with a HST comparable interior comes out at) and the 5-car Class 180 both come out at ~0.98L per 100 seat.km.

Meanwhile the figures for the HSTs are rather confused trend somewhere between 0.76 and 0.89 seat.km, with higher values for the longer 2+8 trainsets.
However, East Coast now operate 2+9 trainsets, and extrapolating from the data points for the 2+7 and 2+8 formations will tend to produce figures in the range of ~0.9-1.0L per hundred seat.km.

In either case, even using the figure for the 2+8 (0.89L per 100 seat.km) the Meridian comes within 10% which means that no real difference exists.
However lets go with this idea that 0.09L/100 seat.km more fuel is used for the Meridian, that translates to roughly 0.43L per trainset kilometre is used extra (for ~480 seats on said 9-car trainsets).
That translates to roughly ~30p at existing red diesel prices.

Now to track access charges: a 2+8 HST formation comes to ~108.6p per set mile, whereas a 9-car Meridian comes out at 94.95p per set mile.
That takes 8.5p per set.km off the HST's advantage, taking us to ~21p/set.km.

So while it appears you are technically correct that per set.km the unit is marginally more expensive to run, it is not a significant effect and would easily be lost in statistical noise since it is a rather small fraction of the cost of running the railway.

And this is before you consider the benefits of journey time savings and the potential reduction in staffing costs resulting from that.
It is certainly not significant enough to make any case for abandoning units and returning to loco hauled operations a lá HST.

 

[Metrailway]

The HST consumption figures from the RSSB Traction Energy Metrics report are based on an ATOC report published in October 2006. Sadly this ATOC report does not seem to be freely available online.

The difficulty with comparing modern HST fuel consumpton figures is that the majority of Class 43s in 2006 had Valenta engines, whilst now they have newer more fuel efficient MTU engines. As the ATOC report is not widely available, I do not know whether they based their study on Valentas, VP185s, or MTUs.

 

[Goatboy]

[*]A 4-car 220 costs 34.88p per mile - so a double Voyager is 69.76p per mile.
[*]An 2+7 HST costs 102.07p per mile.[/LIST](I'm assuming they have roughly the same passenger capacity.)

Not sure this assumption is right. An 8 car car voyager has lower capacity than a 7 coach HST does it not?

Plus do we need to account for the fact XC randomly lock out the second Voyager in a double Voyager formation depending on the day of the week and/or allignment of the moon

 

[sprinterguy]

Not sure this assumption is right. An 8 car car voyager has lower capacity than a 7 coach HST does it not?

You are correct: A Crosscountry 2+7 HST has 70 first class seats and 389 standard class seats, a pair of Class 220 Voyagers has 52 first class seats and 348 standard class seats.

 

[ainsworth74]

It really is easy to forget how terrible the interior design of the 220/221s is sometimes.

 

[yorkie]

You are correct: A Crosscountry 2+7 HST has 70 first class seats and 389 standard class seats, a pair of Class 220 Voyagers has 52 first class seats and 348 standard class seats.

If the Voyager fans wish to make a valid comparison on the basis of seats, they'd need to use a 4+5 car Voyager as comparison (even then the HST still has more seats!)

Also I bet the anti-HST brigade are quoting the old engine fuel usage figures; MTUs use "18%-20% less" (Roger Ford, Informed Sources )

As for track access charges, it was recognised that certain 'lardbutt' DMUs are actually being undercharged, as track damage is higher than previously thought. In comparison, the HST track access charges are being over-charged for.
--- old post above --- --- new post below ---

It really is easy to forget how terrible the interior design of the 220/221s is sometimes.

Yes, though this was partially down to some design rules changing part way through the design process, so not entirely the train designers' fault, but at the end of the day, all that matters to passengers is, they are woeful!