Saint Class 135 ish mph

And I still question the accuracy of stop watch readings taken on the footplate of a speeding light engine. I doubt it was riding smoothly.

 

This still leaves the question about how it was supposed to stop in a reasonable distance if travelling at 100 mph with only the engine brake to retard it? Surely some consideration would have been given to the matter by experienced and practical railwaymen, if not by amateur enthusiastic fans. At least "City of Truro" had a train of sorts to aid its retardation on its high speed run.

Sorry but a lot of valid questions remain unanswered here.

Peter James

 

[FX:Sigh] So did Collett.

 

The experienced and practical railwaymen on the footplate would have known at what point they needed to stop accelerating and when to apply the brakes. The same way you do when you are driving your car and you see the end of your street.

 

Absolutely. The claim stands or falls on the ability of a Swindon No1 boiler to produce sufficient steam (under any conditions) to perform such a feat for even a couple of minutes.

A couple of related general questions: Are a boiler's given steaming rates predicated on the average quality of coal any design is intended to use? And: Since poor quality coal obviously impairs steaming, is it reasonable to suppose excellent quality coal would enhance it?

The one factor which gives me pause for thought is the credibility of the witnesses. Had it been a lone gricer, however widely published (!!), or a retired driver 'in his cups', I'd say "no way", had it been one of those Swindon publicity jobs, I'd have insurmountable doubts. Surely, had such a claim been beyond the realms of possibility, there'd be record of mumblings of discord (back then, not now!). There again, why would a man of CBCs standing leave himself open to ridicule by mentioning, over two decades later, an unsubstansiated (& by then already historic) report concerning one of his predecessors designs?

Do I believe 135mph? No. Do I believe 100mph+? Yes. Do I believe 120mph? I remain to be convinced either way. Whatever happened 111 years ago, it makes for a damned good story!

For the record, and lest a terminal case of Swindonitis be suspected, my own pet standard gauge companies are, (lost causes) Isle of Wight Central, WC&PR : (pre-grouping) Highland and LB&SCR : (off-piste) GNR(I) and the Southern (the 1923-47 one!!).

 

I think GNR(I) supporters would dispute it was standard gauge.

 

Standard for Ireland!

 

Point taken but the RPSI guys on the 2015 tour insisted it was broad gauge.

 

Mention has been made of other locomotives, than the Saint, which have achieved very high speed runs.
What has not been mentioned here, so far I don't believe, is how the locomotive fared after the fast run. We all know the well publicised run in 1938 where the loco had to take it easy, to Peterborough, in case it broke!

 

Fair enuf!!.... You get my general drift tho' & whatever, I'm still very partial to the line. I've got an inexplicable liking for the six coupled AL, PG, SG & SG2 classes. Jolly well proportioned & useful locos...... (continues rambling to self)

 

Indeed I do.

 

I did some additional number crunching. Please note that I gladly bow to someone doing better. It appears from the Perform program that steam comsumption
is about a constant 32000 lbs from 100 mph onwards, don't know why, the internal calculations of the program are hidden to me. Anyway, the standard steam raising capability would be some 22000 lbs/hr so it needs forcing the boiler to its limits but not unlikely.
Then the resistance, Phillipson p.34, gives some formulae, wheel diameter not correct. However it gives some numbers if the formulae are averaged and the lb/ton is multiplied by the weight of the light engine. It varies from 10000 lbs at 130 mph to 6800 lbs at 100 mph.
If the Tractive Effort of the Perform program is compared to the calculated resistance they appear about equivalent at 114.5 mph.
The calculation has been done wit a cut-off of 15%, I have no idea whether that is possible, Phillipson showed 20% as lowest in a numbers of tables.
Please draw your own conclusions, with calculations it is: garbage in-garbage out!
Kind regards
Jos Koopmans

 

Very interesting info. Might I ask whether account of calorific value of the fuel is taken by the Perform software? Does it include this as a fixed average or a variable?

Perhaps I'm misunderstanding the nature of the software, but would that 32KLbs (couldn't resist!) steam production limit preclude using Perform on something really steam hungry, such as a UP 'Challenger' or 'Big Boy' going full tilt with a heavy load?

 

Just had a go at this in Train Simulator for a laugh more than anything else, 116MPH was highest I got

 

After doing it's pres runs over Whiteball with Load 5, Mike Notley was of the opinion afterwards that certainly 3440 was capable of a 100MPH descent following a good climb, Course it doesn't answer the age old question of did it or didn't it, but certainly adds weight to the belief it was possible.

Not withstanding, I believe 3440 took what was then the record for climbing Dainton westbound on the outward run.

 

The fuel is not taken into account. The 32KLbs is case specific, when I use 20%c.o. it becomes 41KLbs. You can try the software yourself, it can be downloaded from the 5AT website.
Kind regards
Jos Koopmans

 

I seem to recall that one of programs or calculation methods which showed Truro incapable of 100 mph also PROVED Duke of Connaught could not have run Bristol to London in under 100 minutes.

 

Many thanks for the reply Jos. My interest in this thread stems from the empirical nature of GJCs designs. I've read through the 5AT site at length (and understand about 25% of what I've read with any degree of certainty!). For one reason or another, it will be a month or so before I'm fully back online, so downloads are on the back burner for now.

The interest in fuel results from following of work across the pond on torrified biomass fuel pellets ( http://csrail.org/ ), as an intriguing adjunct to the works of Chapelon & Porta. None of this, be it noted, in any professional capacity!

 

If you mean would a Std 1 boiler perform better on Edwardian coal (big lumps, few small pieces or dust) compared to the coal used in BR tests in the 1950s, I would say yes. Larger lumps mean bigger air gaps - less grate resistance to air flow - so more air flow for the same draught. The poor coal used in 1950s required a sharper blast to overcome the increased grate resistance caused by the clogged grate. Also large lumps - esp when burning in a thick bed and becoming fused together - are less likely to disappear up the chimney when the loco is working hard.

So more air and less fuel lost = more steam.