Imaginary Locomotives

[Gibbo675]

4 minutes ago, 34theletterbetweenB&D said:

 

Oh dear,

 

The fact that a 22 ton bunker had to be replenished after 200 miles gives a good idea of the power output these locos were required to deliver.

Hi 34B&D,

 

Not forgetting of course, the appalling thermal efficiency of steam locomotives !!!

 

Gibbo.

[RLBH]

11 minutes ago, 34theletterbetweenB&D said:

 

Oh dear, brain fart there. I never had a memory problem until, I forget when exactly...

 

I am in no doubt at all, that in actual service the Milwaukee Road F7 4-6-4 for the Hiawatha services was the fastest steam loco. This because it regularly achieved a scheduled 81 mph end to end speed over a 73 mile route stage. To achieve this there is no avoiding sustained speeds well over the 100mph mark to allow sufficient time for acceleration and braking.

 

(And yet: the most fantastic part of this operation was the provision of an over track coaling station near the mid-point of the 400 mile Hiawatha route at New Lisbon. The fact that a 22 ton bunker had to be replenished after 200 miles gives a good idea of the power output these locos were required to deliver.)

My rule of thumb, and a surprisingly consistent one, is that end-to-end journey times on rail give an average speed about two-thirds of the maximum speed. Apply that to the Hiawatha, and you get a service that was probably routinely hitting 120mph.

 

Didn't the over-track coaling stations also need facilities to empty the ash pan whilst in service? Or was that the NYC Niagaras?

[AlfaZagato]

5 minutes ago, RLBH said:

My rule of thumb, and a surprisingly consistent one, is that end-to-end journey times on rail give an average speed about two-thirds of the maximum speed. Apply that to the Hiawatha, and you get a service that was probably routinely hitting 120mph.

 

Didn't the over-track coaling stations also need facilities to empty the ash pan whilst in service? Or was that the NYC Niagaras?

Niagras for in-service cleaning.   Fun picture, which I don't have to hand, of men in fancy outfits standing in the firebox.

[Gibbo675]

On 08/07/2019 at 00:03, melmerby said:

Not if it was never tried.

It should be well capable, that doesn't mean it did.

A Coronation should be able to beat Mallard but was never tried in similar circumstances.

There are plenty of claims of "super" speeds for locos but not many have been officially (or even unofficially) properly timed.

If a "Scot" had done over a ton someone would have claimed it.

 

Hi Kieth,

 

There is always the certain probability that fast running was not bragged about for such tales of high speeds were clamped down upon by the operating department despite the rule book stating that driver ought to endeavour to regain lost time by using the power of their engine where circumstances allow. Late running was caught up by running the locomotive as fast as was judged safe until point to point timings were back to where they should be. These timings were noted in quarter minutes against various land marks upon notes made by the driver and checked against his watch. When you also take into account that most locomotives were not fitted with speedometers until the late 1950's and only a select few express locomotive had speedometers from the late 1930's onwards, the only way to judge actual road speed was by timings taken between mile posts.

 

When working main line some years back most of the older drivers had hand written point timings kept in note books that they would check against such land marks. Actual road sped not being of any particular interest to them other than that they were not over speeding in any particular section especially over TSR's which is the only time they payed any real attention to the speedometer.

 

Gibbo.

[The Johnster]

1 hour ago, RedGemAlchemist said:

Which I was totally unaware of. 

It was not a thing that reflected any credit on anyone aboard and was not spoken about much at the time.  Practice was to test run new locos light engine down to Stoke Gifford (Bristol Parkway now) and, if no problems had been encountered on the run down, go for a fast run back up.  This has aroused the interest of the signalmen who started timing the up runs. 

 

Apparently, it had developed into something of a sport, and the CME’s department, though not the CME himself, and somebody bet somebody else a sum of money that a brand new loco could achieve 100mph on one of these.  There were some big names on the footplate, including Collett who alluded to the incident many years later.  

 

They got up to a very high seed between Hullavington and Little Somerford, and had difficulty bringing the loco under control for the 50mph speed restriction through the junction at Wootton Bassett.   WB’s distant was on when they sighted it but luckily the junction signals cleared in time. 

 

It was a highly dangerous and stupid thing to do and they should have known better.  A collision with an up Bristol line train was far too narrowly avoided for comfort, and everybody was thoroughly and properly ashamed of themselves; Churchward was by all accounts livid. 

 

Rumours got out of course, and the thing was never officially fully confirmed.  Several versions were in circulation at one time; I was told by an old ganger in a pub once that the loco had been the Dean Single Duke of Connaught and the location the Severn Tunnel!

 

 

[john new]

Anyone interested in either compounding or theoretical discussions about Mallard's speed effort should note the SLS Journal recently ran articles/follow up correspondence on both topics. Back numbers available (PM me for a price - paper or PDF available) and sometimes f-o-c as promo material  (while stocks last) on the stand at exhibitions. Next possibility to find copies - our stand at the Bridport exhibition 27th July.

Edited July 9, 2019 by john new

[melmerby]

2 hours ago, RLBH said:

My rule of thumb, and a surprisingly consistent one, is that end-to-end journey times on rail give an average speed about two-thirds of the maximum speed. Apply that to the Hiawatha, and you get a service that was probably routinely hitting 120mph.

 

 

The Cheltenham Flyer did a timed 81.6mph start to stop average in 1932 so by your calculations it was going nearly as fast as Mallard.

However the GWR, always one for the publicity, never claimed a very high top speed for the run and this was when top speeds were being bandied about by the LMS & LNER

[The Johnster]

Indeed.  The publicity value was in the Swindon-Paddington average, the ‘fastest passenger train in the world’, and the very pedestrian timings Cheltenham-Gloucester-Swindon were overlooked.  

 

The ‘Hiawatha’s’ effort was over a much greater distance with the better part of 1,000 tons of train, though.  The NYC Niagaras on the 20th Century Limited, 1,000 tons at 100mph peak in everyday service, are what I regard as the ultimate steam achievement, though!

 

I mean, seriously, how many people need to travel between London and Cheltenham (where nothing of any significance has ever happened) in a normal day?  And how many between New York and Chicago?

[Compound2632]

There was discussion recently of Duke of Connaught's run with the up Ocean Mail on 9 May 1904, Swindon to Paddington covered in 60.25 min pass to stop - 77.0 mph average; 80.0 mph flying average from Shrivenham to Westbourne Park, 70.3 miles; speed must have been pretty steady down the Vale of the White Horse and on through the Thames valley; the fastest section was the 17.8 miles from Twyford to West Drayton, 82.9 mph - looking at the average speeds quoted by O.S. Nock, Speed Records on Britain's Railways, I don't think a maximum higher than 86 mph was achieved. Nock states that the maximum speed recorded on any Cheltenham Flyer run was 95 mph; a very high maximum was not required because there were practically no speed restrictions travelling up from Swindon - Reading was run through at 91 mph! Get going, find the sweet spot, sit back and let the engine (and fireman) do the rest.

[RedGemAlchemist]

Hmm. All very interesting discussion. Why did nothing that interesting ever happen in this part of the network? 

[brack]

I'm afraid I can't buy all the apocryphal/anecdotal stories. I don't doubt there were some very quick runs, often unofficial, but at a time when speed was being used as a marketing tool, when several railways had put effort into record bids, I don't see why anyone who had exceeded the record, or who could see that they might easily beat a record, wouldnt give it a go for the publicity. It wouldnt have cost them much and the benefits were pretty obvious (certainly its cost less and be worth more than they were paying on publicity and advertising anyway). If a coronation could've so easily surpassed Mallard's record then it'd be in the LMS' interest to do it. The usual argument I hear is that WW2 stopped all the fun, but there was over a year between Mallard's run and the start of the war.

Likewise if a T1 routinely hit 140mph it would have been worth the pennsy making something of it. I would expect though that a new build T1 with modern materials and techniques should surpass mallard (likewise a new build A4 ought to be better than a loco built to 30s standards/materials). In many ways it is anomalous that a British loco should hold the speed record. US lines have the advantages in terms of axle loading, loading gauge, distance between stops and so a much more powerful machine can be built. However US practice seemed to be focused on shifting much heavier train weights rather than out and out speed.

[AlfaZagato]

Our problem with speed runs here stateside are both lack of protection of the right of way, and crap signaling.   National limit is 70mph, has been 70mph for decades, and will likely remain so.   Only the Northeast Corridor is allowed higher speeds now, and that is a dedicated line with no crossings or freight.

[timbowilts]

18 minutes ago, AlfaZagato said:

Our problem with speed runs here stateside are both lack of protection of the right of way, and crap signaling.   National limit is 70mph, has been 70mph for decades, and will likely remain so.   Only the Northeast Corridor is allowed higher speeds now, and that is a dedicated line with no crossings or freight.

I thought you were allowed 89mph for passenger trains if some form of train stop gear was fitted and 110mph if Positive Train Control was active?

[Northmoor]

3 hours ago, The Johnster said:

I mean, seriously, how many people need to travel between London and Cheltenham (where nothing of any significance has ever happened) 

The staff of GCHQ might claim otherwise, but we'll never know 'cos they aren't allowed to tell us..........

[RLBH]

11 hours ago, melmerby said:

The Cheltenham Flyer did a timed 81.6mph start to stop average in 1932 so by your calculations it was going nearly as fast as Mallard.

However the GWR, always one for the publicity, never claimed a very high top speed for the run and this was when top speeds were being bandied about by the LMS & LNER

It's a rule of thumb that, by observation, works fairly well for normal trains running to normal schedules. Give or take maybe 10%. That a crack express given a clear run all the way might do better, or a relief getting checked at every signal do rather worse, doesn't overly bother me. It's a quick and dirty way of estimating running times given almost no information.

 

Thinking of 2-6-2s and 2-8-2s – the Gresley V2 and Powell's Britannia-boilered 2-8-2 have pretty similar adhesive weights and tractive efforts. And both proposed for similar fast freight work. Presumably the Coleman 2-6-2 would have been similar again. The main difference is the size of the driving wheels and how heavily they're loaded. So, what's to choose between six 6'2" drivers and eight 5'6" ones on an express freight locomotive?

[Niels]

3 hours ago, RLBH said:

 

 

Thinking of 2-6-2s and 2-8-2s – the Gresley V2 and Powell's Britannia-boilered 2-8-2 have pretty similar adhesive weights and tractive efforts. And both proposed for similar fast freight work. Presumably the Coleman 2-6-2 would have been similar again. The main difference is the size of the driving wheels and how heavily they're loaded. So, what's to choose between six 6'2" drivers and eight 5'6" ones on an express freight locomotive?

 

Ten 4 feet8  wheels is better.

WD 2-10-0 with 50% reciprocatory balance and better frame

[RLBH]

3 hours ago, Niels said:

 

Ten 4 feet8  wheels is better.

WD 2-10-0 with 50% reciprocatory balance and better frame

Perhaps, although the designers at the time didn't think that way. 

 

Certainly the adhesive weight and tractive effort on a WD 2-10-0 is, again, about the same. And with a similarly-sized wide firebox, though I'd be curious about ash pan capacity.

 

Though, if a 4'8" 2-10-0 - why not a larger-wheeled (say 5', or 5'3") 2-8-0 with the same power output and the same weight on the drivers?

[Niels]

2 minutes ago, RLBH said:

Certainly the adhesive weight and tractive effort on a WD 2-10-0 is, again, about the same. And with a similarly-sized wide firebox, though I'd be curious about ash pan capacity.

 

 

Ashpan capacity on 9Fs with five feet drivers were bigger than on Stannier Pacifics.

[Corbs]

Another Caprotti 8F.

Perhaps it should have the cabside star for balanced motion/higher speed ability?

I quite like it.

 

Edited July 10, 2019 by Corbs

[34theletterbetweenB&D]

2 hours ago, Niels said:

Ashpan capacity on 9Fs with five feet drivers were bigger than on Stanier Pacifics.

That's by measurement. In heavy service, the all too frequent choking of the side sections of the ashpan nullified this theoretical advantage, by restricting airflow to a third of the grate. That still left the 9F with as much grate area as an 8F, so it could complete the job it was on, but in a more pedestrian fashion than would otherwise have been the case had the full grate area been burning coal.

[Corbs]

Wanted to set myself a challenge of creating the rumoured Crosti/Caprotti Standard 5, using only images from Wikimedia Commons, on one cup of tea.

Results are in the video....

 

 

Or here if you can't be bothered with all that....

 

Edited July 10, 2019 by Corbs

[Gibbo675]

8 hours ago, Corbs said:

Wanted to set myself a challenge of creating the rumoured Crosti/Caprotti Standard 5, using only images from Wikimedia Commons, on one cup of tea.

Results are in the video....

 

 

Or here if you can't be bothered with all that....

 

Hi Corbs,

 

Here, quote 55 at 5:09, is what Obi Wan Kenobi thinks !!!

 

 

Gibbo.

[scots region]

22 hours ago, Corbs said:

 

Or here if you can't be bothered with all that....

 

Hmm, the valve gear doesn't quite match the rest of the photo, but thats really the only complaint. It certainly nearly fooled me at a glance, I'm particularly impressed by the smokebox number plate, and I'd never have figured it out if it hadn't been shown to me. I could add that the 9F boiler looks a bit too big to my eyes, but that's not fair. 

 

10/10

 

better than any crude effort I could do.   

Edited July 11, 2019 by scots region

[Corbs]

You're right, I found it very difficult to convert high quality colour images to low quality B&W - added loads of grain and crushed the whites right down but it could still use some refinement. My excuse was that I ran out of tea!

 

I couldn't find any images on wikimedia commons that matched the angle and were also in B&W (there was only one usable image of a proper Crosti!) so had to make do, but that's part of the fun I guess

[scots region]

On that note, could a 9F boiler fit on a ST 5MT chassis? I'll have a look a me standards book.