Reasonable loading in 21st Century

Given that, with the exception of Tornado, the mainline loco stock currently available is now quite an age, what is an acceptable load per power classification? I know that in the good old days of steam many locos would take an exceptional load, but then they were readily available and routinely maintained and repaired quickly. - and that is no criticism of todays engineers.

My concern is that we have an ever growing steam tour industry with a diminishing number of mainline steam locos with some failing at the last minute or out of commision. With a growing market and a need to make a business case for each tour, are locos being expected to pull too many coaches for their power classification and being flogged, or worse still having to be assisted and losing the credibility of the steam tour.

So what is, in the 21st Century, a reasonable load for a Class 5, Class 6, Class 7 and Class 8. Pity the 9Fs cannot be mailnline certified - where there's a will etc - as they would add value.

 

Surely would be route dependent? I suspect you'd end up with a complex matrix of commonly used routes, classes and loadings...

Tom

 

...........er possibly a bit like the BR loading books you mean?

Certainly there was a BR(W) version & logically the other regions had similar.

Its difficult to see a reason why these are not used as they specify loads by loco class between various points across the network which were aimed at maintaining the timetable rather than being the absolute limit which each class could pull.

 

Quite surprised, given the expertise on here, that no recommendations have been forthcoming.

 

how old are some of the mainline stock, really?

Scotsman if/when it comes back is virtually a new loco
A few of the black fives have come back onto mainline work recently after having not worked for half a century

Doesn't it also depend on the route ?

Tangmere did Southend Central to Sailbury or somewhere, I'd expect that it could handle a coach or two more on that than if it was asked to take on Shap or S&C

 

So ok - what is a reasonable load for the Southend Central to Salisbury as a less challenging route for each class? Then what is the same for the Shap/S&C? That puts some perspective into the question.

 

When a Bulleid WC took a train over Shap earlier this year I commented that this seemed a huge risk on the timetable. It then went over the S&C and, whilst hardly romping up to Ais Gill, the difference between what it could do on a 1 in 75 and a 1 in 100 was clear to see. I also pointed out that, despite their both being in Class 7, a WC was nowhere near as powerful as a Scot. It has a substantially lower tractive effort despite the advantage of smaller wheels; its cylinder capacity is only some 76% of the Scot's and its adhesive weight is only 92%. This is not a criticism of Bullied who had produced a wide-firebox machine with a wonderful boiler and with the lightest axle load of any Pacific to enable modern motive power to penetrate the Southern's fragile western extremities. If you want a Class 7 Pacific to match a Scot you need a Britannia or a MN.

It does make one wonder whether the old companies might have spent more wisely in beefing up their track and structures instead of expecting their CMEs to produce so many specialised machines.

 

MN is a Class 8. It was fairly common to see WC/BBs deputising for MNs and attached to Class 8 loadings on the Southern, generally between London and Southampton/Salisbury, but this shows that it all depends on the route's gradient profile. You also have to remember that a Scot is a 4-6-0, so it will have inherently better traction on gradients due to the greater adhesive weight, as you have mentioned. Even these struggle on gradients such as Druimuachdair and Slochd when unassisted, with 46115 stuck in the mid-late 20s with 10 (approx. 386t) carriages last month (it was as low as 16mph on the return, as we had a signal check at Culloden on the final stretch of level track before the start of the 21 3/4 mile climb up to Slochd). However, 34004 on 13 July 1948 achieved 46mph on the climb with a load of 380t, accelerating up Druimuachdair after a stop at Blair Atholl for a Pickersgill 4-4-0 banker to be attached. In fact, 34004 winded this locomotive on the climb to the extent that it proved of little use. So once again, Bulleids are certainly hill climbers, but only with the right loads.

 

As mentioned in an earlier post, there are so many variables.

Glad that you have reminded us of the exploits of 34004 during the locomotive exchanges; speaks for itself really, however, one variable could be that 34004 had a 280lb. p.s.i. boiler at the time, which would go some way to make up for the the cylinder dimension comparison with a "Scot". The WC/BBs would have been designed for a specific cylinder power output relative to the installed boiler pressure, a reduction of 30 p.s.i. is bound to make a difference no matter how well the boiler produces steam.

Cheers

Alan

 

I wonder if people are overtly worried about the 'age' of a locomotive? Someone above noted Scotsman's many years of preservation exploits compared to some other locos hitting the mainline for the very first time.

Surely an effectively conducted overhaul that passes all the tests should give you a locomotive capable, more or less, of its classes standards? The only variable will be the cost of the overhaul!

 

But what are the Class Standards?

 

The usual behaviour you might expect from a locomotive of a specific class. By which I mean you would expect Sir Keith Park to be on about the same level as Eddystone, UoSA the same as Bittern.

The mileage of the loco overall isn't important - it is the quality of its most recent overhaul, and the mileage covered since then, surely?

 

Interesting thoughts.
Every Class had its bad egg. The Royal Scots had 46131, always a poor steamer no matter what was done to it.
If I remember correctly, the Western Region "Bristolian" was always hauled by Castle class locos that had been overhauled at Swindon within a certain timescale.

 

They did indeed, but the question I'm asking is:

Should 8003 Cathedral of Winchester, which covered 1,543,624 miles in service and has since covered 84,206 miles in preservation, and has just come out of its third preservation overhaul, be considered weaker to 8005 Cathedral of Salisbury, which covered 1,543,624 miles in service and has just come out of its first preservation overhaul?

 

There are variables here.
If 8003 has had its cylinders rebored three times without liners being fitted and had its tyres turned three times without new tyres being fitted, assuming the boilers on both locos have been overhauled to the same standard, then 8003, in theory, would be the stronger loco. This is, of course, dependent on both 8003 and 8005 having the same cylinder bores and tyre sizes when they entered preservation. Also, it would depend on the steaming ability of the boilers, No two boilers are the same. There are too many variables to give a difinitive answer to your question, in my view.

 

Fair points indeed, but these are engineering points you are raising. My question is should 8003 be treated more kindly than 8005 just because it has more preservation miles on the clock?

Some people like to say 'Oh A4s are old they couldn't do 90 safely' or 'Clan Line shouldn't pull 13 anymore'. My question is 'If the loco is well overhauled, why not? Should it be considered more tired and weaker and perhaps even less safe (not implying this myself, but it has been in the past) because they are old?

 

Now then, I agree with the A4 comment. At the heavy general overhauls at Doncaster Works, normally about every 2 years, the A1, A2, A3 and A4 class locos were taken apart and literally rebuilt. Has any A4 had that done in preservation. The answer is an emphatic NO.
With regards to loads, surely it depends on what road it is travelling. An A4, Merchant, Duchess or any other loco could take a greater load between Doncaster and Newcastle than between Crewe and Carlisle. The reason being the East Coast Line is less arduous than the West Coast Line.

 

I think Bittern had a pretty thorough rebuild last time, as the frames had to be repaired.