Large and Small locomotive economics, ex-West Somerset Railway developments

It can, and has been, done. Standard 4s on the NYMR regularly run 10,0000 miles a year. WD 2-10-0 3672 ran about 115,000 miles in the course of its 10 year ticket, I think, and the NYMR was only 18 miles long back then! (effectively, it's about 25 now). The WD, though, was well knackered by the end of it and hasn't run since, so possibly it wasn't the best idea.

 

The figures are really a guide as much as anything else. 100k miles between overhauls would be an exceptional figure on a preserved railway, though I believe the NYMR have achieved it with at least one loco and the WSR got very close with 9351. You have to remember as well that daily loco duties may be more than the crew duties. For example, on a Saturday on the Bluebell (an 11 mile line), one of our two service engiens runs 4 round trips (=88 miles) and one runs five (=110 miles) because of an evening Golden Arrow. Lines running larger locos are also more likely to have extended midweek seasons: on the Bluebell, a typical weekly duty would be about 440 miles, say 1750 miles between washouts. You wouldn't have to cycle through that too many times to start getting at least to the 7-8k miles per year for a pre-war era loco, and might start to get towards 10k miles in some cases.

But my more general point is that you can't talk about the coal cost per mile in isolation: you also have to factor in the overhaul and maintenance costs, and ideally spread that out to give a mileage rate. A larger loco that uses more coal, but is either cheaper to overhaul (due to working easily and not getting so much wear and tear) or else can run a bigger mileage between overhauls may in total have a lower daily cost than a smaller loco that works harder or can run fewer days per year. And the flip side is that if you really work an elderly loco, it should perhaps not be too surprising if it has to be withdrawn well before its nominal "ten yearly". Last year our H class ran 7,900 miles, but I would be amazed if it ran 79,000 miles between overhauls: either it won't last ten years, or we will have to reduce the annual mileage. In pre-preservation days there were maintenance schedules, either mileage or time based, for all sorts of issues on a locomotive: they weren't done for fun, but because they were needed and born out of long experience. As an example, the King Arthurs would generally need attention to the axleboxes after about 20,000 miles because they tended to start running rough, whereas a Schools would run twice that mileage without attention.

Tom

 

Well, I can think of a couple at least where it rings a bell!

As I think I have previously commented on the "daddy" of this thread, wide or narrow firebox is the big difference in the cost of lighting up and keeping a fire in - I suspect the difference in coal consumption "on the move" is less and the "dynamics" are different - a large loco on a reasonable load may even use less coal actually on the move than a small one being worked hard on the same load.

The amount of coal and time spent on lighting up and not actually moving is generally far greater in preservation use than it would have been "in the day". Locos would stay in steam and many would work over longer distances (although some wouldn't). The shorter the line, the more time is spent running round at either end! (Not great for cooling and warning of the firebox either).

The problem many locos face is find sufficient work to enable a suitable income. While the "top few" (in terms of passengers numbers and public profile) run long period of daily service, at most these are 7 months of that daily running season and that only makes just over 200 days. If there is a cycle of 25 days in action and 5 on washout/maintenance, that is 175 days maximum assuming no failures or unplanned stoppages. On the NYMR, that is just about what 75029 and 61264 have achieved the past couple of years, and it works out at 12,500 to 13,500 miles by the time "out of season" running is added. 80135 once did over 18,000 miles in a 12 month period, but that was only possible due to the off peak timetable being 144 miles for a single loco, 36 of which were light engine.

Running such mileage does mean mechanical work is needed more often than the "10 year" but as this is effectively a "cost per mile" anyway, it means the high cost of boiler work is spread over a greater amount of usage. I know that the reverse - very little usage = little to do at 10 years and mechanical and boiler all at the same time - has proven successful for some, but my understanding from a man who knew is that boilers will still need a major rebuild sooner or later which could easily double the cost of an overhaul simply due to age and the fact it has been used at all. It is these occasions when you see £ 1/2 million overhauls, while I have seen a number of figures of nearer £ 1/4 million quoted for more "normal" 10 years here and elsewhere. (Figures for Class 4 to 6 locos typically).

Steven

 

And that list should answer all those who say we rescued the wrong locos from Barry. 43924 was the first loco to escape Barry in 1968, by which time a lot of small locos had been scrapped. If the Bulleids had all gone to the melting pot first, then more smaller locos would have been preserved. It's as simple as that.

 

Having skimmed through this thread.
One thing hasn't come up is the type of coal used. Ie Welsh coal is burns very hot where as Scottish coal doesn't have the same amount of heat in it.
Recently on the SVR a year long survey was conducted around the usage of coal. The SVR now uses the new welsh coal and currently the most economical engine is 34053 as the steel firebox retains the heat for much longer than a copper box.

 

This is a most interesting debate. Now all the posts are in a dedicated thread it makes it much easier to follow or review. Thanks to the Mods for moving it here.

 

Where did that little "fact" come from or was it in a similar vein to post 1 of this thread?

 

This comes from talking to paid staff during mid weeks during the year. And results of the coal survey.

 

Paid MPD staff directly concerned with coal have given a totally opposite view!

Just shows that you can only really deal in facts such as those provided earlier in the thread by the WSR CME - everything else is heresay.

 

What this thread demonstrates is the empirical nature of much of the information and that the decisions can rarely be optimal because of all the factors that come into play.

To comment on the thought about smaller engines and "what was available from Barry". I agree that lines that started later and therefore rely on the ex-Barry engines to a greater extent tend to have the larger locomotives (huge generalisation I know). IF the ownership of locomotives were not so fragmented would we see a more fluid exchange of locomotives with some of the smaller locos no longer able to keep up with the demands of their "home" moving to other places that might make use of them?

At the end of the day though, does any of this actually matter so long as the compromises that any given railway has to make are ones which it judges it can deal with? Probably not.

 

Some BR-era data about average mileages between General and Intermediate repairs of a number of locos of broadly similar size, which would roughly equate to what you might hope to get over a ten-year span on a heritage railway. These figures are what was being achieved in the mid 1950s. It is also worth pointing out that there is a lot of variation in these figures - i.e. they are averages, but some locos in a class would achieve more, and some less.

BR 75xxx - 93,395
Lord Nelson - 93,012
Schools - 79,447
H2 - 69,353
King Arthur - 62,972
U1 - 58,330
MR Compound - 53,844
U - 50,317
N15X - 45,771

(For the non-SR aficionado, an H2 is the Marsh Atlantic of the type being constructed at the Bluebell. An N15X is the Maunsell rebuild of the Billinton L class 4-6-4T as a 4-6-0 tender engine. A U1 is the three-cylinder version of the class U mogul of the type preserved on the Bluebell and Swanage).

Broadly, that supports the view that the older designs require more maintenance than the more modern ones, though the mileage obtained by the Lord Nelson's is admirable. I also have repair costs per mile, which interestingly show that - based on the conditions pertaining in the 1950s at least - the U was more expensive to maintain than a Lord Nelson: presumably the extra complexity of the LN was more than compensated for by the far higher mileage it could obtain between overhauls.

Tom

 

Looking at that list a few more 2-6-0's would have been useful, but there's probably more pannier tanks than the hobby would ever need.. that said 9491/2/6/9 would have been a bargain.. built 1954/5 withdrawn after 4 years... I don't know what was more wasteful, throwing away an 94xx after 4 years.. or building class 14's a few years later to do their kind of job.. that also went in the bin after 4 years..

 

Ah, right you are: I was remembering the summer of 1980, when two engines were cut up due to a lack of any other work for the men.

Still, that list shows that of the 76 scrapped, most were in 1965 and before (scanning the list quickly, I only saw four after that - 1 in 1972, 1 in 1973, and 2 in 1980), which is before the preservation movement really got rolling; as against 213 saved.

So I think my main point (that the selection of engines we have today is not due to the preferences of the enthusiasts who retrieved engines from Barry, but mostly due simply to what went to Barry) is still valid.

Noel

 

Agreed but think of all the "cut and shut" jobs the GW boys could have done with them.

 

Has anyone tried extracting fuel costs from heritage railway accounts and then worked out "cost per mile"? They would, I am sure, be "averages of averages" in a large part but it may provide at least some real life data about the type of work we are really looking at.

For example, what mileage is run each year on the IoWSR (I have copies of recent accounts) or West Somerset?

Steven

 

What does "retains the heat" mean here?