Imaginary Locomotives

[Coryton]

I remember a mock up of a 59 with EW&S livery in one of the magazines, before the lightning stripe for new locos had been decided upon. Then of course EWS bought the 59s anyway in the end....

 

And painted them without the lightening stripe.

[Corbs]

As I understood it, only brand new locos had the lightning stripe, whereas pre-owned ones had the straight one.

[Satan's Goldfish]

Ok, 8f, and the Mega-8. (how would it compare to a 9f?)

[34theletterbetweenB&D]

A well designed Berkshire (2-8-4) for fast freight should be capable of 3.500 dbhp continuous (mechanical stoker on about 70 sq ft of grate, 1400 sq ft superheater, boiler pressure and cylinder volume arranged for 45,000lb TE on 68" drivers.) It wouldn't much resemble the 8F, the boiler tapering is restricted by the superheater area requirement for a start. BR's power rating scheme doesn't get anywhere close to having a rating for a monster like this: logically enough because it was 'too much of a good thing' to be really practical in the steam era, unless it had a matching build of high capacity automatically braked bogie wagons for a long distance service. It would quite happily match a current class 5 freight diesel in loadshifting ability.

 

The LMS sketched up a 4-8-4 of these proportions as a fast freight unit. It would be better as a 2-8-4, as the wheelbase reduction thus obtained on the loco usefully increases the wheelbase and thus frame length of the tender for more coal capacity. The LMS drawing shows 12T coal: 20T would be more like it for decent range on a maximum load, as a firing rate of ten tons an hour would be required when fully opened out going unassisted up Shap or the 'Long Drag'. And there needs to be water in the troughs every time on a non stop run.

[Corbs]

Do you have a copy of the LMS sketch? I would be interested in seeing that.

[LNWR18901910]

F

 

Ok, 8f, and the Mega-8. (how would it compare to a 9f?)

Fascinating engine, that! It's worth attempting in model form, I hope.

[Satan's Goldfish]

F

 

 

Fascinating engine, that! It's worth attempting in model form, I hope.

Given my taste and era in steam, it may need to be based on something slightly different, which I may need to work on drawing next...

[34theletterbetweenB&D]

Do you have a copy of the LMS sketch? I would be interested in seeing that.

 Published in Haresnape's Stanier Locomotives.

[rockershovel]

The LMS sketched up a 4-8-4 of these proportions as a fast freight unit. It would be better as a 2-8-4, as the wheelbase reduction thus obtained on the loco usefully increases the wheelbase and thus frame length of the tender for more coal capacity. The LMS drawing shows 12T coal: 20T would be more like it for decent range on a maximum load, as a firing rate of ten tons an hour would be required when fully opened out going unassisted up Shap or the 'Long Drag'. And there needs to be water in the troughs every time on a non stop run.

10 tons/hr? Apparently 20 tons/day was reckoned good going for a railway navvy http://www.railwayarchive.org.uk/stories/pages.php?enum=LE123&maxp=8&pnum=1 and we all know that sixteen tons a day just wasn’t enough, so DEFINITELY in mechanical stoker territory..

[34theletterbetweenB&D]

Mechanical stoker and probably a servo operated valve gear, as mandated on US loco designs with this power potential. Bear in mind that is just for short bursts when maximum output is required to maintain speed up the steepest gradients, which are not that long in the UK. Go through Tebay at 75mph, reach Shap doing 50mph eight minutes later is the plan. It is imperative to go fast with this design of loco at its rated load. There isn't sufficient adhesion to go slow, let alone restart such a train from a stand on the gradient. Operationally, traffic regulation would be a challenge for this type of operation: such a train gets a clear road come what may..

[Zomboid]

Up to date freight wagon equipment (basically American practise with automatic brakes throughout and bogies) would have had a major impact on freight train speeds. They'd have been much more able to keep up with passenger trains, and so long trains not fitting in a loop wouldn't have been such an issue. Which would have driven a need for things like the 2-8-4s and maybe even bigger. The LNER P1 might have turned out useful at least.

It's not locomotives, but imagine replacing all those silly little 4 wheeled vans with things like GUVs. Makes a lot of sense for main line operation, but the bucolic branch line goods yard would have been a very different proposition.

[Corbs]

Maybe we need an imaginary stock thread....

[Regularity]

I wonder how much hidden, long term damage the common user obligations caused freight transportation and environmental harm. 2-8-4s were designed to shift long trains at good speeds, far above safe limits for short 4-wheel wagons.

Not just the common-user obligations, of course. In what was a typical short-term view of paying dividends rather than investing, many customers simply did not want to change their operating practices, as the GWR found out with the South Wales coal exports.

[LNWR18901910]

I decided to make a Mk 2 version of my LNWR Mogul using a G2A as the basis. What do you guys think?

[rockershovel]

Not just the common-user obligations, of course. In what was a typical short-term view of paying dividends rather than investing, many customers simply did not want to change their operating practices, as the GWR found out with the South Wales coal exports.

I had a conversation of this sort with a Dutch colleague at the time of the Brexit vote, along the lines that the general destruction of the financial system in WW2, along with the near-complete removal of the land-owning classes followed by enormous sums of basically, free money from the USA meant that German and Dutch industry was able to take a far more rational view of its requirements, than ours. Significantly, there doesn’t appear to be any British equivalent of the German term “mittelstand”

[Corbs]

What's the advantage over a G2A? Won't it have less adhesive weight as the cylinder weight is carried on non-driving wheels?

Correct me if I'm wrong, but aren't moguls developed to be faster versions of 0-6-0 locos, as the pony truck is able to lead the drivers into corners, and you can add more weight at the front in the form of bigger cylinders like the LMS Crab?

[rockershovel]

What's the advantage over a G2A? Won't it have less adhesive weight as the cylinder weight is carried on non-driving wheels?

Correct me if I'm wrong, but aren't moguls developed to be faster versions of 0-6-0 locos, as the pony truck is able to lead the drivers into corners, and you can add more weight at the front in the form of bigger cylinders like the LMS Crab?

It does also occur to me that outside cylinder 0-6-0s are rare, and largely confined to shunting. The Q1, the most highly developed 0-6-0 was inside cylinder. Does the pony truck add lateral stability and allow mainline speeds?

[Northroader]

What's the advantage over a G2A? Won't it have less adhesive weight as the cylinder weight is carried on non-driving wheels?

Correct me if I'm wrong, but aren't moguls developed to be faster versions of 0-6-0 locos, as the pony truck is able to lead the drivers into corners, and you can add more weight at the front in the form of bigger cylinders like the LMS Crab?

There’s the consideration that the extra leading axle would allow a larger boiler to be fitted, besides improving the ride.

[Corbs]

Yes. So what would be gained from converting an 0-8-0 to a 2-6-0? More stability/lower rates of flange wear, at the expense of adhesion?

 

 

I was thinking about starting an imaginary wagons thread but for now I'll post this here

 

Edited January 26, 2018 by Corbs

[DCB]

The 2-8-4 looks good but thinking about it there is no room for inside cylinders LMS GW or BR Std style. Two outside cylinders wouldn't have been any bigger than a 9F which was at the limit of the loading gauge and the TE would probably have come down to around 34 000 lbs with 250 lbs pressure so we would have a machine capable of the same power as a Royal Scot but able to burn far more coal.  I suppose they could have worked in inside cylinders with a shorter stroke to minimise length but would the resulting monster have steamed?  The Caley 3 cyl 4-6-0s with dis similar valve gear inside to out did not.

 

The problem the UK has is width over cylinders, the Yanks can go to 28" we can't exceed about 21",  thats getting on for twice the volume and hence power and our need for 3 or 4 or even 6 cylinders.   Only Gresley really made a neat 3 cyl arrangement, with an inclined inside cylinder. driving the middle axle The Rebuilt Bullieds were similar and might have been a better basis for a BR 4-8-2 or 4-8-4.

Both 3 and 4 cyl  LMS versions made the loco excessively long.   The Helmholst truck, 2 bogie wheels and the leading drivers in one truck proposed by Bulied for his 2-8-0 MN proposal of around 1938 might have solved the problems but people would have shuddered at a loco without a proper bogie running at 100 mph especially after the River incidents.

 

The G2 based LNWR 2-6-0 seems a bit pointless in view of the Whale 19" goods a 5'2" 4-6-0s which did the same job as a 2-6-0 a lot better and the LNWR built quite a few compound 2-8-0s before realising that they were better without the leading truck and outside cylinders.  On the other hand the Webb 4-6-0 compounds know as Bill Baileys should have remained imaginary locos as seldom has anything quite so useless run on British Rails.

 

The usual reason for going 2-6-0 from an 0-6-0 is either better riding or the weight of a Superheater making the front end too heavy, The Flying Pig Ivatt 4MT was planned as an 0-6-0 at one stage, and Gresley followed the Ivatt 5'8" fast freight 0-6-0 with the original K1 2-6-0 while developing the 0-6-0 as an 0-6-2T.

 

The GW 2-6-0s were essentially 2-6-2 tanks without the tanks. 

[Corbs]

Yes, I did say it was a 2-cylinder.

 

The versions with 2 leading wheels have been shortened at the front and bigger cylinders added to make it a 2-cylinder (in fact the cylinders are pinched from a 9F making them 20" x 28" rather than the four 16.5" × 28" of the Coronation).

 

I used them because they were the largest I knew of that would fit in the UK loading gauge.

 

It's a goods engine with 8 smaller driving wheels, so really what we should be comparing it to is an 8F with 32,400lbs TE, but this is capable of much higher sustained output at speed (therefore ability to keep to passenger timings). Less weight over the drivers, but higher overall weight, so I'd imagine similar starting ability, certainly better than a 'Scot'.

 

Of course the 9F is a superior design, but remember that it was still 10 years away in the fictional universe the 2-8-4 lives in.

[Northroader]

The best place to look at 2-6-0s was France around 1900. The standard goods engine was an outside cylinder 0-6-0 for a lot of lines, and most ran a programme involving adding a pony truck and a larger boiler to these, upgrading the fleet fairly cheaply.

[rockershovel]

Yes, I did say it was a 2-cylinder.

 

The versions with 2 leading wheels have been shortened at the front and bigger cylinders added to make it a 2-cylinder (in fact the cylinders are pinched from a 9F making them 20" x 28" rather than the four 16.5" × 28" of the Coronation).

 

I used them because they were the largest I knew of that would fit in the UK loading gauge.

 

It's a goods engine with 8 smaller driving wheels, so really what we should be comparing it to is an 8F with 32,400lbs TE, but this is capable of much higher sustained output at speed (therefore ability to keep to passenger timings). Less weight over the drivers, but higher overall weight, so I'd imagine similar starting ability, certainly better than a 'Scot'.

 

Of course the 9F is a superior design, but remember that it was still 10 years away in the fictional universe the 2-8-4 lives in.

Interesting abstract here http://www.lococarriage.org.uk/steam_locos.html making clear reference to the development during the 1930s of 2-8-4, 4-8-4 and 2-10-4 types, superseding the earlier mallet types as AVERAGE train running speeds increased, although maximum running speeds in scheduled traffic had not increased significantly since about 1910

[rockershovel]

This all seems to indicate that the British loading gauge tended to prevent effective utilisation of the increased firebox size permitted by four-wheeled trailing bogies.

 

So, although the principles and much of the detail were known by the early 1930s, the LMS decided that such designs were not viable, no one else seriously investigated them (the LNER having demonstrated that 2-8-2 types were only marginally effective compared to the usual 2-8-0 designs)

 

The whole issue was overtaken by the development of the BR Standard 2-10-0, which maximised potential within the British loading gauge and operating environment ... and no-one else was seriously studying the issue at all by then..

[Corbs]

But effective at what? The 8Fs were dealing with plodding trains of 4 wheeled wagons, whilst the Black 5s were handling the faster fitted loads.

But what if we need to go faster, with huge bulk loads on vac fitted bogie stock? Black 5s may be maxed out on that, especially on gradients where a four coupled design may be more sure-footed. WD 8Fs haven't been invented yet. We need huge amounts of sustained power in order to keep to passenger speeds and avoid having to lengthen all the goods loops.