Imaginary Locomotives

[DenysW]

2 hours ago, The Johnster said:

Wouldn’t precision alignment of the hornblocks

My marginally-engineering brain believes that anything you attach to a bolted-together (or welded-together) frame you have the same task to perform with a cast frame, and the similar challenges to do it at the precision your design requires. The advantages of the cast frame are mostly greater strength and lighter weight, although there (should be) better precision achievable in a single-stage process (casting) than a multi-stage process (casting followed by assembly). Casting the frame should therefore improve the precision achievable (at constant effort) across the board compared to plate or bar frames.

[Ohmisterporter]

On 15/01/2023 at 16:45, The Johnster said:

 

The case of the Highland Castles is a bit odd and something of a one-off.  The locomotives were not ordered by the Caledonian and built by the Highland to order, rather they were built by the Highland for it's own use and found to be 'unsuitable' due to weight and hammer-blow issues by the Highland's Civil Engineer.  This was against a background of known personal animosity between that officer and the CME, and may well indicate that the engines were in fact perfectly fine for Highland use, but that the CCE saw his chance to put the knife in and acted on it!  It led to the CME being sacked; imagine if the GW had sacked Collett because the Kings were a bit on the heavy side to the exent that their route availability was compromised!

 

The Highland Castles were therefore put up for disposal to anyone that wanted to buy them, and the Caley bought them.  How this was done legally is not known to me, but it seems probable that the engines had been written off from capital stock and sold as surplus material, scrap in other words.  Apparently the Caley liked them, and they were used on the Highland section by the LMS without any issue. 

 

 

 

 

 

 

That was the Highland River class. They were found to be slightly high at the chimney and dome; nothing that could not be easily rectified. 

[tythatguy1312]

24 minutes ago, Ohmisterporter said:

 

That was the Highland River class. They were found to be slightly high at the chimney and dome; nothing that could not be easily rectified. 

Apparently they were also too heavy, which caused the management to demand them gone. However, when combined with hammer blow, they weren't any heavier on the track than the Castles they were intended to supplement

[rockershovel]

Working on a cast frame gives the great advantage of eliminating the joint faces. Every interface is a source of both inaccuracy and weakness. 

 

It means the cylinders can be bored with direct reference to their partners and to the frame itself, rather than relying on the accuracy of assembly. 

 

However it also introduces the problem of controlled cooling, so that the piece does not distort due to unequal thermal stresses - at which point the whole piece is useless. 

 

British industry actually had a great deal of experience of this arcane technology - look at the huge castings featured in bridges and stationary engine bases. What they DIDNT have, was experience of carrying it out at speed using modern materials. The Americans developed the technique for casting pieces such as tank hulls and turrets. 

[rodent279]

Back to Imaginary Locos. 

 

Looking at a side on view of a GWR 28xx 2-8-0, it seems to me that there is a lot of space between the rearmost driving axle and the end of the footplate. Could they be turned into a 2-10-0?

Would be interesting to see a photoshop/artwork, if only to see what it looks like!

[DenysW]

From GreatWestern.org (but my highlights):

 

  The prototype of the '2800' class, number 97, was the first locomotive to operate in Britain with this wheel arrangement. It was fitted with the Standard number 1 boiler working at 200 p.s.i. and cylinders of 18 inches diameter. In order to allow some flexibility over the 16 feet 10 inch wheelbase, the tyres on the second and third pair of driving wheels used thinner flanges and the front pair of coupling rods were fitted with spherical joints in order to permit a small amount of side play. It was renumbered 2800 in 1906.

 

So I think you are moving the BR Standard 9F backwards in time to the 1930s. Not a bad idea at all.

[JimC]

2 hours ago, rodent279 said:

Back to Imaginary Locos. 

 

Looking at a side on view of a GWR 28xx 2-8-0, it seems to me that there is a lot of space between the rearmost driving axle and the end of the footplate. Could they be turned into a 2-10-0?

Would be interesting to see a photoshop/artwork, if only to see what it looks like!

 

I suppose in theory it would look something like this. In practice though it would be of very limited utility, since there would be little weight for the rearmost wheels to carry. A 2-10-0 with a 47xx, Castle or even King boiler, on the other hand, would be a more useful proposition.

 

Edited January 16, 2023 by JimC

[tythatguy1312]

25 minutes ago, JimC said:

 

I suppose in theory it would look something like this. In practice though it would be of very limited utility, since there would be little weight for the rearmost wheels to carry. A 2-10-0 with a 47xx, Castle or even King boiler, on the other hand, would be a more useful different proposition

 

In theory extra weight could be placed by moving the cylinders (and by extension the pilot bogie) further forward. A Somewhat similar solution was used on the front (well the rear) of the Italian GR670's

Edited January 16, 2023 by tythatguy1312

[JimC]

But better to put a proper boiler on it!

This is a King boiler on much the same chassis. If I were doing it a bit more thoroughly I would juggle with the wheel positions to get the fixed wheelbase shorter, this was (obviously) a quick hack job - oops, look at the top feed!

Edited January 16, 2023 by JimC

[Northmoor]

9 hours ago, JimC said:

It varied. At worse string (well hopefully not in the 20thC). At best the GWR introduced Zeiss optical alignment kit in I think the 30s, and Cook (NE and E CME, ex Swindon works manager) introduced optical alignment to the ex LNER post war. I don't know about the SR and LMS.

I was amused to read of in the late 80s of how York works started measuring and cutting the extruded aluminium sections which made up Networker's floors, to an accuracy of 1mm in length.  That's 1 in 23000.

 

I say amused, because other industries like aviation tended to look down on railways as old-fashioned and low-tech.  When I worked in a small way on the (later cancelled) Nimrod programme, it had become known that one of the problems with integrating new systems into the airframes was that the major dimensions could vary, by INCHES.

[rodent279]

1 hour ago, JimC said:

But better to put a proper boiler on it!

This is a King boiler on much the same chassis. If I were doing it a bit more thoroughly I would juggle with the wheel positions to get the fixed wheelbase shorter, this was (obviously) a quick hack job - oops, look at the top feed!
T

Thanks.

I'm not sure what, if any, advantage there would be in turning a 28xx into a 2-10-0, or whether the Great Way Round would have had any use for such a machine. Possibly reduced axle load? But the lines that would require a reduced axle load probably wouldn't have the sort of traffic to justify them. Maybe these would fall into the same class as the LNER P1/P2's - too powerful for the requirements of the day and the limitations of the infrastructure? 

I guess there's a reason why none were built.....

[rockershovel]

Interesting that the BR 9F was both lighter and less TE than the P2.. presumably reflecting the experience of running the earlier 2-8-2s. 

[The Johnster]

There was a beefed up 10-coupled version of the 72xx with a King boiler, which was actually a serious proposal that got as far as a general arrangement drawing and a weight diagram, and has featured several times on this topic.  I believe it was intended for the Newport Docks-Ebbw Vale iron ore traffic, one of the heaviest-loaded jobs in the country and uphill all the way, banked from Aberbeeg.  The 5202 2-8-0 tanks used on this traffic suffered with excessive tank leakage caused by the frames being distorted under load by the sharp curvature of the Western Valley line, which even now enforces low speeds on the passenger trains using it, so a 2-10-2T would have been even harder to keep supplied with water...  IIRC, like the 2-8-0T, it drove on the second axle not the third. 

 

Fair to say that the Ebbw Vale iron ore traffic was unusual, a special case, and was eventually in the hands of BR Standard 9Fs, which allowed the load to be increased from 28 to 35 wagons.  There were two other similar uphill iron ore jobs, the Tyne Dock-Consetts, also eventually given over to 9F, and the Port Glasgow-Motherwells, also in the hands of Riddles 2-10-0s, in this case the WD Austerity type.  Kings had been trialled on the Ebbw Vale trains, perhaps with the 2-10-2T proposal in mind.  Of course, a tank engine can place useful tractive weight over the rear driving wheels better than a tender engine, so the 2-10-2T would have had better T.E. than the 2-10-0 fattened 28xx described here.

 

2-8-0s were adequate for heavy freight work in the UK until the speed of the trains increased, to which the response was the 9F.  Express goods with lighter loads was handled by mixed traffic 4-6-0s and later by light pacifics, notably the Thompsons and Bullieds; the Britannias were designed as mixed traffic engines.

 

Given that most British main lines are limited as to train lengths to 60 'Basic Wagon Units', later 'Standard Length Units' but the same thing, a length based on the length over buffers of a 10' wheelbase wagon.  This determines the length of loops, layby sidings, and signalling safety overlaps, allowing for double heading or pilot engines.  It is increased in some areas to 90 or 100 BWU/SLU, where very long household coal trains were run in to London from places like Stoke Gifford, Toton, Peterborough, Annesley, Rugby, &c, but special double-blocking signalling arrangements had to be provided and clear runs guaranteed through stations and over junctions, and paths provided between loops long enough to cope and let faster traffic pass.  So there was not much point in building heavy freight engines that could handle more than 60 loaded wagons at 25mph on normally graded track, and at the low speeds of unfitted trains, 2-8-0s were more than adequate.  Block fitted trains became more common in the 50s, just in time for 9Fs to pull them at higher speeds.

 

Those goods engines that were bigger than 2-8-0s, like the LMS Beyer-Garratts and the Gresley P1s were specifcally purposed for these long London coal trains, and were too big to be economically viable for 'normal' traffic.  The P1s had 3 cylinders and boosters to assist smoother starting in order to reduce coupling breakage; the GW's approach was to develop the stronger instanter coupling.

[The Johnster]

9 hours ago, Ohmisterporter said:

 

That was the Highland River class. They were found to be slightly high at the chimney and dome; nothing that could not be easily rectified. 

 

Yes, I realised that after I'd posted.

[Michael Edge]

The Highland River 4-6-0s fell foul of an internal political row between the chief civil engineer and the CME. The CCE said they were too heavy which forced the resignation of the CME and the sale of the locos to the Caledonian, they had to reduce the height by this small amount to fit their loading gauge, they were quite happy with the weight. This rumbled on into LMS days when the Highland route was investigated to check what axle weight was allowable, I think this involved three underbridges which had to be strengthened a bit to allow the use of heavier 4-6-0s - including the new 5MTs and the Rivers which did eventually run on the Highland as intended.

[62613]

19 hours ago, DenysW said:

And if the UK had followed the US and Europe into frames as single steel castings, would it have been needed?

 

Note: my shallow reading of the US experience is that going to single-piece cast frames by the 1930s (a) had required a complete re-tooling such that tasks like boring-out of cylinders was done horizontally not vertically and (b) reduced the companies capable of casting the frames to one or two from lots. So it's not a simple "Bah! Humbug! British Industry fails not modernise, then just fails. Harumph!" It might not have been economic on our scale, especially with the Big Four mostly locked into in-house loco production. But worth a thought.

Wasn't capital for investment into new plant difficult to come by in the UK after WW1? Especially given the size (financially) of a large number of UK manufacturing companies; another thing that has bedevilled our manufacturing base.

Locomotive engine beds, even for the "little" ones made in the UK, would require some form of rig to ensure even cooling of the casting, and so on. I believe marine engine builders had the necessary plant for this, for instance, but they wouldn't come cheap.

 

[62613]

16 hours ago, DenysW said:

My marginally-engineering brain believes that anything you attach to a bolted-together (or welded-together) frame you have the same task to perform with a cast frame, and the similar challenges to do it at the precision your design requires. The advantages of the cast frame are mostly greater strength and lighter weight, although there (should be) better precision achievable in a single-stage process (casting) than a multi-stage process (casting followed by assembly). Casting the frame should therefore improve the precision achievable (at constant effort) across the board compared to plate or bar frames.

Less chance of the single - piece casting failing at the rivetted and/or bolted joints, too!

[tythatguy1312]

6 hours ago, The Johnster said:

  I believe it was intended for the Newport Docks-Ebbw Vale iron ore traffic, one of the heaviest-loaded jobs in the country and uphill all the way, banked from Aberbeeg.  The 5202 2-8-0 tanks used on this traffic suffered with excessive tank leakage caused by the frames being distorted under load by the sharp curvature of the Western Valley line

I do believe that this may be a route where an articulated locomotive may be preferred, at least compared to a 2-10-2t. A 2-6-6-4t Mallet might be worth something on the work, though other proposals could also work. That being said it'd be fairly inadequate for other work.

[Ohmisterporter]

1 hour ago, Michael Edge said:

The Highland River 4-6-0s fell foul of an internal political row between the chief civil engineer and the CME. The CCE said they were too heavy which forced the resignation of the CME and the sale of the locos to the Caledonian, they had to reduce the height by this small amount to fit their loading gauge, they were quite happy with the weight. This rumbled on into LMS days when the Highland route was investigated to check what axle weight was allowable, I think this involved three underbridges which had to be strengthened a bit to allow the use of heavier 4-6-0s - including the new 5MTs and the Rivers which did eventually run on the Highland as intended.

 

The CCE of the Highland was Alexander Newlands. He went on to become CCE of the LMS, so he must have been good at his job or the internal politics that always bedevil amalgamations. FG Smith quit railway work altogether but in private he told friends that if his name began with "Mac" he would never have been fired. IIRC I read that in a potted history of the HR Rivers in one of the railway magazines some years ago. Smith was succeeded as CME by Christopher Cummings whose Clan class 4-6-0 was accepted by Newlands, though the axle loading was one ton heavier than the Rivers when hammer blow was taken into account. Fascinating subject this railway history business.

[DenysW]

8 hours ago, The Johnster said:

Fair to say that the Ebbw Vale iron ore traffic was unusual

And has its own thread which has stopped me re-hashing old ground. Using info from it plus some guesswork on weights, shifting 35 loaded wagons at 25 mph would have needed 46,000 lbf tractive effort and at least 3,000 hp from Aberbeeg to Ebbw Vale. No wonder it was a job demanding (UK frame of reference) the most powerful locos available.

 

[The Johnster]

The issue with the Ebbw Vale iron ore trains is that the line is steep from Park Jc (Newport) to Risca, steeper and curved from Risca to Aberbeeg, and precipitous from Aberbeeg to the steelworks reception sidings.  It's a tough job for an engine, but superpower in the form of Beyer-Garratts, Malletts, et al is only really needed on the last pitch above Aberbeeg, where bankers could be supplied as there was a shed there.  I am guessing here, but the GW seems to have worked with what they had, the 5205s with larger cylinders, because the locos could haul 28 of those loaded hoppers up to Aberbeeg, where a banker was attached.

 

The routine then was for the banked train to arrive at the steelwork and run over the ore bin into which the hoppers emptied, at which point the banker became the train engine for the descent back to Aberbeeg while the original train engine acted as a steam-powered brake van.  Thus running around was avoided, and time/money saved so that the banker paid for itself.  When they got back down to Aberbeeg, the train engine which had been the banker came off and the original train engine and brake van were run around for the run back down to Newport. 

 

It sounds unneccessarily complex, but was in fact a reasonably efficient and cost-effective way of dealing with the geography.  There were attempts to increase the head end power, including trials with double-headed Kings, but as a banker had to be provided to haul the train back down to Aberbeeg anyway to save time at the steelworks, the established method of working, the 5205s were kept at it until the advent of the 9Fs in 1954.  The first of these engines were sent to Ebbw Jc for this work, and disgraced themselves by leaving spectacular smoke trails up the valley; it didn't help that the trials began on a Monday, traditional valleys washing day...  The later batch of double-chimneyed 9Fs proved suitable and were the last of steam on the job, with the 35-wagon loads but still banked from Aberbeeg. 

 

37s replaced them, but proved inadequate, leading to type 4 power being used in the form of 47s and 52s, and including 1200 Falcon after her purchase by BR.  In later years type 5 power in the form of 56s and 60s eliminated the need for bankers.  The 8-coupled GW tanks were very powerful engines for their size and no.4 boiler, but not entirely suited to the Western Valley's sharp curves, while the obvious alternative, 28xx, had slightly longer coupled wheelbases and were not quite capable of the tractive effort of a tank engine with full tanks, on which keeping the water in the tanks was the main problem.

 

The valley between Aberbeeg and Cwm is the steepest part of the route and is even now relatively undeveloped, steep sided and narrow with heavily wooded hillsides.  The sight and sound of a double-chimneyed 9F climbing it, banked by a 94xx, (13F in BR terms) both blowing holes in the sky at about 15mph, must have been impressive!  There was an even madder iron ore run in South Wales, though, to Dowlais steelworks, 56xx and all of 15 loaded wagons, piloted and banked from Bargoed by more 56xx, 5 wagons per loco up the precipitous slopes of the upper Bargoed Rhymni valley beyond Darren & Deri out over the open moors in the wind and the rain, which comes at you uphill here, to Cae Harris.  Couldn't have helped Dowlais Works' cost effectiveness much.  But as illustrations of the sheer brutality of railway work in the Valleys, both these workings serve excellently!  In steam days you were rarely out of the sound of an engine working, hard!!!                                            

[AlfaZagato]

Would blind drivers or more complicated lateral motion devices been worthwhile on the 5205s?

[rodent279]

If frame racking was an issue with 5205's, would a 4 cylinder version perhaps manage better? The drive being more eveny spread about the longitudinal centreline of the frames, there would be less tendency to twist.

Can @JimC photoshop a 4cyl 5205? Maybe there would need to be some sacrifices of hallowed Swindon design concepts, such as equal length inside & outside con rods?

Edited January 17, 2023 by rodent279

[Northmoor]

4 hours ago, The Johnster said:

It sounds unneccessarily complex, but was in fact a reasonably efficient and cost-effective way of dealing with the geography.  There were attempts to increase the head end power, including trials with double-headed Kings, but as a banker had to be provided to haul the train back down to Aberbeeg anyway to save time at the steelworks, the established method of working, the 5205s were kept at it until the advent of the 9Fs in 1954. 

It's not as twisty but the traffic on the Worsborough incline East of Penistone wasn't dissimilar.  The efficient solution to the Ebbw Vale traffic problem was electrification.

[tythatguy1312]

29 minutes ago, Northmoor said:

It's not as twisty but the traffic on the Worsborough incline East of Penistone wasn't dissimilar.  The efficient solution to the Ebbw Vale traffic problem was electrification.

the Great Western doing something as modern and advanced as electrification? Don't be preposterous, they'd sooner make a Swindon built copy of the TGOJ M3t for the work