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Imaginary Locomotives


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Rockershovel said "...That would have resulted in a 2-6-0+0-6-2 type, and since BR had exactly such a class available, with experience of using them for heavy mineral work, and could have conducted the experiment .... there must be some legitimate reason why this wasn't done.  ..."

 

Apart from the grate size, the LMS Garratts were under-boilered compared to the Standard 9Fs. So even if you fix the other well-rehearsed Midlandisation errors, they still are likely to be under-powered for the UK version of extreme mineral freight, which this seems to be. Plus, to achieve 18 tons/axle they really needed to be 2-6-2+2-6-2, which was what Beyer Peacock recommended.

 

So I come to the conclusion that use of a Garratt would have worked if re-engineered by either Swindon or Beyer Peacock, probably as a 2-8-0+0-8-2 - possibly with an extra water tender, as a few of the South African versions. This would probably have failed any BR small class size test, though.

 

Edited by DenysW
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1 hour ago, pete_mcfarlane said:

 

Or a du Bousquet, for extra weridness?

https://en.wikipedia.org/wiki/Du_Bousquet_locomotive

I would think that a du Bousquet would be well adapted to Welsh conditions. The central position of the cylinders deals with the problem of overhanging cylinders fouling the loading gauge, and there is minimal overhang and side-throw. Much shorter than a Garratt and with better draughting than a Kitson-Meyer. The 0-6-2+2-6-0 configuration would be no problem in a region where the 0-6-2T was already well established. Not very fast, but that's not a problem; same for limited range due to restricted tank capacity. 

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As debated previously and resolved, the du Bousquets used briquettes, which would have needed to be neatly stacked on every re-fuelling. That, or a version with a bigger hopper to use coal, or an evaluation whether only about 3 tons of coal was enough for these fairly short routes. Nice locomotive, of course.

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28 minutes ago, DenysW said:

As debated previously and resolved, the du Bousquets used briquettes, which would have needed to be neatly stacked on every re-fuelling. That, or a version with a bigger hopper to use coal, or an evaluation whether only about 3 tons of coal was enough for these fairly short routes. Nice locomotive, of course.

I would have thought that the bunker could been reconfigured to hold considerably more. The tall drivers would need reducing to fit the loading gauge, too

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What advantage does a multi cylinder Mallet or Garret combo have over a conventional engine layout? Is it just the flexibility of the layout, allowing tighter curves to be negotiated?

I'm asking because I don't understand how say a 2-6-0+0-6-2, or a 2-6-6-0, would have an advantage over a conventional 2-8-0, or 2x 0-6-2?

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9 minutes ago, rodent279 said:

What advantage does a multi cylinder Mallet or Garret combo have over a conventional engine layout? Is it just the flexibility of the layout, allowing tighter curves to be negotiated?

I'm asking because I don't understand how say a 2-6-0+0-6-2, or a 2-6-6-0, would have an advantage over a conventional 2-8-0, or 2x 0-6-2?

 

I stand to be corrected but I believe the main advantage is the flexibility. A longer frame can negotiate the tighter curves, and a longer frame means a longer boiler and firebox and hence a more powerful engine. They also have more driven axles, hence better adhesion. Mallets and Garrets have been known to have the separate portions run at different speeds, one portion slipping badly and the other still adhering to the rails. Not recommended though.

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My guess is the Mallet configuration would be problematic with the British loading gauge.

In addition to the above a big advantage of the Garratt is that the location of the boiler permits a considerably larger diameter boiler within the GB loading gauge, and also, I think, there are fewer constraints on the location and proportions of the firebox. 

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53 minutes ago, rodent279 said:

What advantage does a multi cylinder Mallet or Garret combo have over a conventional engine layout? Is it just the flexibility of the layout, allowing tighter curves to be negotiated?

I'm asking because I don't understand how say a 2-6-0+0-6-2, or a 2-6-6-0, would have an advantage over a conventional 2-8-0, or 2x 0-6-2?

They can negotiate tighter curves (horizontal and vertical) and worse track that an equivalently-powered rigid locomotive. Running costs are less than two engines because of only needing one crew, but maintenance costs are higher than a single rigid engine.

 

In practice, this means that fast lines (which of necessity need good track and gentle curves) tended to go for large rigid-wheelbase locomotives, whereas more lightly built, slower railways often perferred articulation if they wanted to run heavy trains.

 

However, even the best-laid railways had limits for the maximum size of boiler that could be carried on a rigid wheelbase and still negotiate the curves, and the greatest cylinder area that could be fitted within the loading gauge. Articulation allowed more cylinders and longer boilers.

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10 hours ago, John Besley said:

Dont forget there is a British Garrett preserved at Bressingham... 

 

... William Francis, of Baddesley Colliery in the North Warwickshire coalfield.

 

But on a point of order, are not all Garratts British by manufacture, the patent being held by Beyer, Peacock & Co.?

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1 hour ago, Compound2632 said:

 

... William Francis, of Baddesley Colliery in the North Warwickshire coalfield.

 

But on a point of order, are not all Garratts British by manufacture, the patent being held by Beyer, Peacock & Co.?

Many Garretts were built overseas and the patent might of run out a long time ago. It is also possible that the overseas built Garretts were made under license or perhaps the actual design rights were held by the company who owned the locomotives.

Dunno, clarification needed

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4 hours ago, PenrithBeacon said:

Many Garretts were built overseas and the patent might of run out a long time ago. It is also possible that the overseas built Garretts were made under license or perhaps the actual design rights were held by the company who owned the locomotives.

Dunno, clarification needed

WHR NGG16 no.87 was built in Belgium by Cockerill, for example. Henschel also built some, other builders too, though the overall majority were Beyer Peakcocks.

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I'm building stock for an imaginary railway company (see the believable pre-group topic) so imaginary locos are part of the game. I've settled on a period in the mid-1870s and I'm looking for something suitable as an older goods loco type now relegated to pick-up goods work. This imaginary company is in Surrey, but that doesn't mean there isn't any heavy stuff to shift. The network serves brickworks and limeworks as well as a number of towns. I already have the bits for a modern (for 1875) 0-6-0  so I want something different. A Bury 0-4-0 like on the Furness was a possibility  but that is a bit identifiable. An 0-4-2 was an alternative.

 

The basis for my imaginary designs is off the peg locomotives from the big builders like Sharps or Stephenson. The aforementioned "modern" 0-6-0 is actually a Cambrian small goods type, but that fits my brief because that was a standard Sharp Stewart design and actually built on spec to keep the workforce at Sharps together through a slump in orders. The six built were offered to smaller companies at knock-down prices so its not hard to divert the two that went to the LCDR to my Surrey Railway.

 

I found a drawing of a suitable 0-4-2 build by Hawthorns for the Great Northern in 1848. The problem was that it was outside framed. As this loco will be scratch built I didn't want that complication so I had a go at redrawing it as having inside frames. The boiler fittings are also later suggesting its onto its second boiler. However a loco of c1850 is likely to have received a new boiler after 15-20 years.

 

851073118_0-4-2goods.png.063ce647404056d76842fd15fc215304.png

When (if) I build it I'll probably put a cab on but here it just has a weatherboard

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28 minutes ago, whart57 said:

However a loco of c1850 is likely to have received a new boiler after 15-20 years.

 

I was for a while much mystified by Matthew Kirtley's rebuilding of various late 1840s / early 1850s 2-2-2s into an assortment of entertaining little 0-6-0WTs in the late 1860s / early 1870s. About the only major component re-used was the boiler, which I would have thought of as the most likely component to be life-expired. But on reading round the subject, it became apparent that boilers made of iron plates ("Best Low Moor") had a much longer lifetime than boilers made of steel, which corroded much more rapidly.

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1 hour ago, JimC said:

From Ahrons " the British steam locomotive" this is Sharp's standard mixed traffic type from 1848-54.

cropped3066337207221089115.jpg.8b3e2ebe1864eb87b1803b62a1c0e87a.jpg

 

Sorry about the phone camera distortion. 

 

 

 

 

Thanks for that, that's even better.

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7 hours ago, Paleopotato09 said:

Going back to the triang S class 0-6-0 saddle tank. They could be rebuilt in some quite interesting 0-6-2 industrial tank engines. Maybe just saddle tank versions of the large engines used on the Lambton system. 

There is the possibility of making some of the lesser known South Wales 0-6-2STs such as the Newport (AD&R) saddle tanks.  The Rhymney went in for 0-6-2STs as well, but the profile was quite different to the Newports.  The Triang Jinty mech is a bit long in the wheelbase for an industrial, though some of the Lambton and Philadelphia systems' engines bucked that trend and were a little more 'main line' in character.

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1 hour ago, Compound2632 said:

which I would have thought of as the most likely component to be life-expired. But on reading round the subject, it became apparent that boilers made of iron plates ("Best Low Moor") had a much longer lifetime than boilers made of steel, which corroded much more rapidly.

Boilers, for obvious reasons, are very strongly built and likely to last for a very long time if they are looked after.  What wears out is the joints between the end plates and the tubes, and any pipe union joints, rather than the cylindrical pressure vessel part. because of the stresses caused by expansion and contraction and by repeatedly depressurising and repressurising.  It is therefore best practice to keep the loco in steam for as long as possible, only letting her go cold when you have to for boiler washout, about once every 2 weeks.  Meantime, she is kept in steam when off duty, usually at a lower pressure but enough to move her about the shed, while her fire is dropped and a new one lit for the next duty.  This minimises the number of heating/cooling and pressure/depressurising cycles that the loco goes through between major overhauls.

 

At overhaul time, the boiler is taken out and very thoroughly refurbished, then tested hydraulically to prove it's pressure integrity.  This takes longer than the rest of the loco, and spare boilers of all types needed are kept on hand in the boiler shop at the works in order to put in to locos to return them revenue traffic and release  the erecting shop bay for the next patient.  The boiler that was taken out will go through full refurbishment and testing in the boiler shop, and be kept on hand ready for the next of that class that wants one. 

 

Standardisation means that a pool of boilers can be used on several different classes, and will migrate between them over their working lives, and even in some cases on to the replacement classes.  The outer part, the casing, can have a very long working life indeed.  They are also probably the most expensive component of a locomotive, and thus is explained Kirtley's re-use of boilers 20 odd years old but still with plenty of service life left in them.

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3 hours ago, The Johnster said:

There is the possibility of making some of the lesser known South Wales 0-6-2STs such as the Newport (AD&R) saddle tanks.  The Rhymney went in for 0-6-2STs as well, but the profile was quite different to the Newports.  The Triang Jinty mech is a bit long in the wheelbase for an industrial, though some of the Lambton and Philadelphia systems' engines bucked that trend and were a little more 'main line' in character.

 

The original 3 (built by Kitson) were essentially a main line design, being mechanically the same as the Lancashire, Derbyshire & East Coast Railway 0-6-2T locos (of which 5 went to the Hull & Barnsley as the LD&EC ran out of money). The first lot became LNER class N6 (as they had been rebuilt with belpaires) and the H&B ones N11 (retained original round top fireboxes). Apart from the cab, LHJC 29/30/31 were almost identical to these.
The Robert Stephenson 0-6-2Ts which followed were designed specifically for the LHJC (I believe) but probably drew upon the experience of the Kitsons.

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