0-6-0T to 2-4-0T conversions. Why?

David Knight
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0-6-0T to 2-4-0T conversions. Why?

Postby David Knight » Mon Jan 19, 2015 5:19 pm

In some idle moments I noticed that the LB&SCR and the Mid Suffolk Light Railway had something in common, they both converted 0-6-0T locomotives to a 2-4-0T arrangement. In the case of the LB&SC it was 'Terriers' that were converted for use with motor trains in the case of the Mid Suffolk no special use is given. The "Terriers" had the front driver replaced by spoked wheels of smaller diameter, the Mid Suffolk simply disconnected the coupling rod.

What would be the reasoning behind this change in arrangement?

TIA

David

Andrew Ullyott
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Re: 0-6-0T to 2-4-0T conversions. Why?

Postby Andrew Ullyott » Mon Jan 19, 2015 5:59 pm

Don't know about the Mid Suffolk, but on the WC&PR it was to get round the extremely tight curve of the exchange siding at Clevedon. Can't remember if it was 10 chains or 22 but it was proper 'radius 1 set-track' territory

Bulwell Hall
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Re: 0-6-0T to 2-4-0T conversions. Why?

Postby Bulwell Hall » Mon Jan 19, 2015 9:14 pm

'850' class saddle/pannier tanks on the GWR also sometimes ran as 2-4-0s by just dropping the front coupling rods - flexibility was the reason so far as I know. Without checking I seem to think that some '2021' class also ran like this but I am not certain about this.

beachboy
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Re: 0-6-0T to 2-4-0T conversions. Why?

Postby beachboy » Mon Jan 19, 2015 9:44 pm

David,

I believe there is no definite historic reason recorded why Marsh went ahead with these alterations on the Brighton; of which he experimented with other Engines prior to the Terriers by removing the front coupled Rods.

It is known that following several accidents with front coupled wheeled loco's, he & others had a unsatisfactory view of this arrangement. And perhaps reflected this when attempting to de-tune the Terriers for Auto work. Which I understand was successful, except for obtaining adhesion on gradients. I assume the likes of the Dyke Branch.

I recall reading of a Drivers concern when proceeding up a gradient with possible wheel lift from the displacement from the low level of water in the tanks on a front coupled engine.

Steve.

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Flymo748
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Re: 0-6-0T to 2-4-0T conversions. Why?

Postby Flymo748 » Mon Jan 19, 2015 9:48 pm

Not forgetting the Great Eastern, of course...

For a short history, and a lovely photo, have a look at Adrian Marks' blog at https://basilicafields.wordpress.com/2014/03/09/the-buckjumper-mk-ii-class-e22-the-blackwall-tanks/

He's also commented elsewhere "In GER and early LNER days the front coupling rods were removed from tanks working lines with sharp curves (Blackwall, Tollsbury, etc) as they believed it reduced flange wear. In later LNER and British Railways periods locos, such as 8211 had them removed when working on dock lines which often had tight radius curves more suited to four-coupled locos."

Cheers
Flymo
Beware of Trains - occasional modelling in progress!
www.5522models.co.uk

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Will L
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Re: 0-6-0T to 2-4-0T conversions. Why?

Postby Will L » Mon Jan 19, 2015 10:24 pm

David Knight wrote:..the Mid Suffolk simply disconnected the coupling rod.



Don't blame the Mid Suffolk light (MSLR). The GER E22/LNER J65 loco used eventually on the MSLR, while normally 0-6-0s, had been run as 2-4-0s since they were introduced on the Fenchuch Street to Blackwall services for which they were built. These service which had previous been the preserve of various 2-4-0 and 2-2-2 locos and it seem the GER liked them like that. Other J65s not so employed normally ran as 0-6-0s. While most did get their front rod back when they left Fenchurch Street, (7)155/(6)8211)* which ended up on the Mid Suffolk always seems to have run as an 2-4-0. One has to wonder if extra bits had got lost. All the J65s that ran on the MSLR had run as 2-4-0s out of Fenchurch Street but at least (7)247/8213**, the only one I can find a photo off, was an 0-6-0 again by the time it arrived at the MSLR. The MSLRs own 3 locos were 0-6-0's (LNER J64) that normally seem to have run fully clad. That said, at the time of withdrawal, no 3 is recorded as having run to Stratford as a 2-4-0 pulling no 2.


* GER no 155 / LNER no's 7155 then 8211 / BR no 68211
** BR no never carried

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Will L
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Re: 0-6-0T to 2-4-0T conversions. Why?

Postby Will L » Tue Jan 20, 2015 11:16 am

I did see Flymo's post that got there before mine but after a happy few hours researching though various sources, I though I'd post anyway. It didn't stop me reading on either.

Since then, more Photo's found but I still can't find one of any of the J65s running on the MSLR as 2-4-0s. However locos running on Ipswich docks did and both the MSLR and the docks were serviced from Ipswich shed's allocation of 4 J65s. The 2-4-0 configuration was prefered for the docks because of the "tight radius curves" it is reported, so one may assume that the Blackwall service rout through docklands was seen in then same light. Another interesting snippet, apparently the GER originally tried them out as 0-4-2s as well but found the 2-4-0 configuration preferable. Like all Buckjumpers the rods were jointed so as to pivot on the middle crank pin, just like many a model 0-6-0, so this game was easy to play.

David Knight
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Re: 0-6-0T to 2-4-0T conversions. Why?

Postby David Knight » Tue Jan 20, 2015 9:41 pm

Thanks to all for the information. There's so much to learn, not all of which comes into play immediately, but comes in handy down the line. I have a project in mind.... :thumb

Cheers,

David

Terry Bendall
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Re: 0-6-0T to 2-4-0T conversions. Why?

Postby Terry Bendall » Thu Jan 22, 2015 8:50 am

I am not an expert on this area, but on the LBSC the main thrust for the change of 0-6-0s came from D.E. Marsh who was locomotive superintendent from January 1905 until February 1911. There is some useful information about this topic in the Oakwood Press book about Marsh written by the well known LBSC authority Klaus Marx.

Apparently Marsh disliked the idea of tank locos with leading coupled wheels, because of his experiences on the GN with one of Ivatt's 0-8-2 tanks and an incident where a Drummond M7 derailed at Tavistock in 1908. Soon after arrival at Brighton Works, Marsh had 20 of the Billington E5 class 0-6-2 locos and two E4s converted to 2-4-2s, by removal of the front coupling rods. It appears this change did not last long and all were converted back by September 1909. Concerning the Terriers, Nos. 81 Beulah and 82 Boxhill, these were converted to 2-4-0s in 1905 for "motor train" work by fitting 3ft dia wheels in extended horn blocks place of the leading coupled wheels. These locos seemed to have worked fairly in this form but were both converted back to 0-6-0s, No 81 in 1910, 82 in 1912. Other Terriers appear to have worked motor trains without this wheel conversion.

Terry Bendall

beachboy
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Re: 0-6-0T to 2-4-0T conversions. Why?

Postby beachboy » Thu Jan 22, 2015 11:19 am

Taking terry's comments further, Holcroft described the extreme rough riding of such coupled loco's following accidents on the GW.
Most BOT reports blame Driver speed in the excess. Despite there was at a point in evolution of no exact speed restrictions as there are today. Some drivers were simply making up lost time, others the boy racers of their day, whom had no regard for thrashing an engine - a driver by the nick- name of 'old dangler' on the Brighton comes to mind.
Marsh as a privileged apprentice of William Dean would have witnessed some of Dean's evolving designs dancing around Swindon works. Such was the experimenting required. If you think, man & his evolving machines, were being demanded to go faster, with heavier loads. And any machine will be subject to lift. Necessary for the first flying machine, but a problem for motor car design, yet alone Loco Engineers on a learning curve.
Front Coupling rods without good weight distribution, will add to the lift effect. Take the body off your similar model loco and see how the rods will try to lift the engine in a given direction.
So removing the Rods would not be the means to solve the problem, hence the replacement, but introducing speed restrictions would. Though such 'problem' engine's were often relegated to secondary use.
I would of thought flange wear would be more relevant to an incompatibility of a given engine design / axle loading, to inferior Permanent Way with severe curvature. Removing the Rods would provide a minimal effect.
Colin Maggs recently wrote of an Austerity being speed tested in a siding at Fairford by locking down the loco, with a view to assessing the given point of speed v lift. That was in the 1950's.

Steve.

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grovenor-2685
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Re: 0-6-0T to 2-4-0T conversions. Why?

Postby grovenor-2685 » Thu Jan 22, 2015 11:55 am

You have lost me a bit here, perhaps it would help to identify better the source of the 'lift'. For the aeroplanes and cars that you use as examples the lift concerned is aerodynamic lift. Are you really suggesting that there is an appreciable aerodynamic lift effect with the steam engines under discussion doing very moderate speeds?
Lift from the rods, usually called 'hammer blow' comes from the out of balance forces and is a completely different effect, not neccessarily helped by removing the rods if the wheels have balance weights but certainly helped by fitting alternative wheels.
So there are potentially two different reasons for conversion to 2-4-0
1. To allow higher speeds without wheel lift, as an alternative to improving the balancing.
2. To allow use on tight curves where the coupling rod bearings are restricting sideplay on the axle.
Regards
Keith
PS. what do you mean by 'locking down the loco' ?

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John McAleely
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Re: 0-6-0T to 2-4-0T conversions. Why?

Postby John McAleely » Thu Jan 22, 2015 9:03 pm

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