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Imaginary Locomotives


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45 minutes ago, AlfaZagato said:

Tendered 2-6-2 'Prairies' were only rare in the UK.   They were fairly common in the US around turn of the century.   They lasted forever here, too.   Looks like Russia & the USSR both favored the type for passenger work.

 

In terms of running qualities the 2-6-2 arrangement has a lot going for it, but the problem will always be fitting the axles round the firebox and grate area. Probably the more generous loading gauge of the US and Russia helped with that.

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2 hours ago, whart57 said:

 

In terms of running qualities the 2-6-2 arrangement has a lot going for it, but the problem will always be fitting the axles round the firebox and grate area. Probably the more generous loading gauge of the US and Russia helped with that.

Then what of Pacifics?  Same issues present there, yet they're one of the most common types worldwide.

 

I do know that one issue with Prairies  is that they like to hunt a bit, having a nominally balanced wheelbase.   Especially if the center was driven, as was common.

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39 minutes ago, AlfaZagato said:

Then what of Pacifics?  Same issues present there, yet they're one of the most common types worldwide.

 

I do know that one issue with Prairies  is that they like to hunt a bit, having a nominally balanced wheelbase.   Especially if the center was driven, as was common.

Would the issue with hunting be due to the position of the pivot for the leading truck, i.e., a bit further back on the chassis? A bogie pivot is going to be a bit further towards the front of the chassis, so may steady things a bit

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14 minutes ago, 62613 said:

Would the issue with hunting be due to the position of the pivot for the leading truck, i.e., a bit further back on the chassis? A bogie pivot is going to be a bit further towards the front of the chassis, so may steady things a bit

 

But that should be compensated for by the transverse springing of the truck; in either case it should be leading the engine into the curve.

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56 minutes ago, AlfaZagato said:

Then what of Pacifics?  Same issues present there, yet they're one of the most common types worldwide.

 

 

At a guess I would say that as a Pacific has a bogie on the front end it can move the rear pony truck back a bit and create more space for the fire grate without unbalancing the locomotive

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2 hours ago, whart57 said:

 

At a guess I would say that as a Pacific has a bogie on the front end it can move the rear pony truck back a bit and create more space for the fire grate without unbalancing the locomotive

 

Pacifics (and Atlantics) tend to have as short as possible a coupled wheelbase in order to prevent the boiler barrel becoming so long that its front end is achieving no useful heat exchange. The leading bogie is under the cylinder block, bearing the weight of the front end. On a 2-6-2, just as on a mogul, the leading driving wheels can be closer behind the cylinder block, so the wheelbase can in principle be a bit greater - compare a V2 with an A3. If you want a really big grate, then a x-x-4 is what you want. But that was hardly found necessary in Britain.

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6 hours ago, Compound2632 said:

Is the rather "stretched" look of the 2-6-2 down to it having the classic Derby 8'0" + 8'6" coupled wheelbase? In modelling terms, is the mechanism off a Bachmann Stanier mogul?

 

Yes, a leftover from the Barry box and a last minute whim, which I quite like, and the comments here have been informative, thank you.  The 2-6-2 is new territory for me and I was constrained by the realistic length I could manage from the melding of two Stanier five boilers and the wheelbase of the mogul. A suggestion of a Fairbairn tank chassis was examined but further to the comments after, I think the longer wheelbase is OK. I may rexamine this again in the future with a shortened Clan boiler as I know the trailing bogie is  a bit lacking, but TBH, broadside views are cruel and when running its shortcomings aren't so obvious.

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13 hours ago, Traintresta said:

I'm curious to know more about the class 4 however.  I was aware of an LMS proposal for a small 4-6-0 for a Scottish line but I think that was meant to be a class 2.

 

Covered in E S Cox's book with a diagram. Basically what emerged as the 75xxx. Plenty of Class 2's around there already.

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11 hours ago, Flying Pig said:

have you tried the model on a Fairburn tank chassis?  I reckon that would give you 4-5mm extra behind the drivers, but now I come to think of it, I don't know whether it would fit otherwise without major hacking.

Took a look at it tonight - a Fairbairn tank lurks around as they were used in 1946, quite successfully, and the wheelbase is a bit less, but opinion suggests that a larger wheelbase might be more realistic. Might be that another go at this is on the cards.

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Is the business need to the 2-6-2 to start replacing the oldest of the 4F 0-6-0s with something more efficient?  By 1946, some are starting to get to retirement at 40 years in service. If so it's for a 4F with an 18 ton/axle route availability - do you think this fits that slot?

 

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56 minutes ago, DenysW said:

Is the business need to the 2-6-2 to start replacing the oldest of the 4F 0-6-0s with something more efficient?  By 1946, some are starting to get to retirement at 40 years in service. If so it's for a 4F with an 18 ton/axle route availability - do you think this fits that slot?

 

 

Surely the type of traffic for which you need a small goods locomotive is the least demanding on engines and in the context of 1946 the least important for which to acquire new locomotives. Patch the 40 year old 0-6-0s up for another ten years would surely be what the company executives would demand

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Or even build new ones - the last 4F 0-6-0s were built in 1941, and with hundreds across LMS there should be spares aplenty. However, one of the themes of this thread has always been 'But what's it for?', and I thought I'd apply that in the least negative way that occurred to me.

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2 minutes ago, DenysW said:

Or even build new ones - the last 4F 0-6-0s were built in 1941, and with hundreds across LMS there should be spares aplenty. However, one of the themes of this thread has always been 'But what's it for?', and I thought I'd apply that in the least negative way that occurred to me.

 

The question "what's it for?" could usefully have been applied to Riddles' BR standards. I fully understand why new steam locomotives were required in the late 1940s, even the Dutch who had all but electrified everything before the war bought dozens. So the Pacifics, the various Class 4s and 5s, the 9F - all those had a clear function to perform. The small ones though, the 2MTs, what were they for? Plenty of pre-war locos to do that job for ten years before diesels are available to take over. (Or Beeching to close the lines  :mellow: )

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1 hour ago, DenysW said:

Is the business need to the 2-6-2 to start replacing the oldest of the 4F 0-6-0s with something more efficient?  By 1946, some are starting to get to retirement at 40 years in service. If so it's for a 4F with an 18 ton/axle route availability - do you think this fits that slot?

 

I'm not quite sure how you get there. The first pair of Midland 4Fs were built in 1911 - 35 years old in 1946 - with volume production beginning in 1917 - 29 years old in 1946 - with most of the LMS standards being in traffic by 1928/9, apart from the last 45 built 1937-41. They had the advantage of using the G7S boiler which was standard across several classes, notably the 2Ps, and hence a standard stock item. That they lasted well into the 1960s is evidence that they weren't life-expired in the mid-40s! Why replace them with an altogether larger machine featuring a non-standard boiler?

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55 minutes ago, whart57 said:

Patch the 40 year old 0-6-0s up for another ten years would surely be what the company executives would demand

Steam locomotives were relatively cheap to build and expensive to maintain, so its well worth replacing old stuff if the replacements have a much lower cost of ownership. Keeping old crocks running comes with a cost in increased repairs and lower mileage between overhauls. The old crocks also have higher coal and oil consumption. So execs with a good handle on the numbers may not be keen on patching up. In 'Swindon Steam' Cook, the head of the works, claims Stars were upgraded to Castles because the bigger boilers would be working at a lower evaporation rate, and they calculated that would save a penny a mile on maintenance.

There's an interesting contrast between GWR and SR policy. The GWR scrapped 19thC and pre group classes through the 30s, (and late 40s and the 50s), and replaced with new build because the new kit was cheaper to run and the investment worthwhile. By the late 50s there was almost nothing 19thC and little pre group left. The SR used the equivalent money on electrification in the 30s because that also enabled them to scrap 19thC kit *and* make major savings in the workforce, but they were left with some old crocks where electrification hadn't reached. Both policies were rational but the war putting a halt on electrification put a major spanner in the SR works. Still, it means we have more interesting old southern types than GWR.

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47 minutes ago, JimC said:

The SR used the equivalent money on electrification in the 30s because that also enabled them to scrap 19thC kit *and* make major savings in the workforce, but they were left with some old crocks where electrification hadn't reached.

 

Thus resulting in the Bluebell Railway having a nineteenth century Stirling 0-6-0 on their books.

 

In the context of this discussion though, those "old crocks" on the Southern were the 0-6-0 goods engines, the type of engine I suggested would be the lowest priority in the replacement schedule

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14 minutes ago, whart57 said:

Thus resulting in the Bluebell Railway having a nineteenth century Stirling 0-6-0 on their books.

 

Would that they did! What they have is an early 20th century rebuild of a 19th century locomotive. 

 

17 minutes ago, whart57 said:

In the context of this discussion though, those "old crocks" on the Southern were the 0-6-0 goods engines, the type of engine I suggested would be the lowest priority in the replacement schedule

 

The Bluebell's O1 illustrates why: because many such locomotives had already been modernised before 1923, so were far from being old crocks. Drummond's 700 Class are another case in point.

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1 hour ago, whart57 said:

 

The question "what's it for?" could usefully have been applied to Riddles' BR standards. I fully understand why new steam locomotives were required in the late 1940s, even the Dutch who had all but electrified everything before the war bought dozens. So the Pacifics, the various Class 4s and 5s, the 9F - all those had a clear function to perform. The small ones though, the 2MTs, what were they for? Plenty of pre-war locos to do that job for ten years before diesels are available to take over. (Or Beeching to close the lines  :mellow: )

I've previously argued on here that dieselisation should have taken place much earlier in the UK, but others have rightly pointed out that the country didn't have the financial ability to purchase so much foreign oil.  With the lack of proven, reliable and powerful enough diesels, the building of the larger Standards was perhaps inevitable.

 

However, you are completely right about BR building locomotives for traffics and roles that another BR department was planning to close.  It's not as if secondary and branch lines weren't already closing in big numbers by the mid-50s (the 1st Beeching report basically just proposed accelerating what was already happening).  There is no way any steam shunting locomotives should have been built by BR; all the Pannier tanks were a complete waste of resources; the EE 0-6-0DE has already successfully demonstrated itself by then.  Although similarly, as they ended up disposing of huge numbers of them at less than 10 years old, BR should have stopped building diesel shunters a lot earlier as well!

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28 minutes ago, Compound2632 said:

 

Would that they did! What they have is an early 20th century rebuild of a 19th century locomotive. 

 

 

The Bluebell's O1 illustrates why: because many such locomotives had already been modernised before 1923, so were far from being old crocks. Drummond's 700 Class are another case in point.

 

Well early 20th century reboilering, the O1s were hardly "modernised". I stand to be corrected but I think the last O1s were kept by BR(S) solely for the EKR stub to Tilmanstone Colliery as newer 0-6-0s were too heavy.

 

Your point about the SR inheriting some relatively modern locos in 1923 could be applied to the large number of Hs and M7s that were the mainstay of branchline passenger services until electrification/dieselisation/closure.

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31 minutes ago, Northmoor said:

all the Pannier tanks were a complete waste of resources; the EE 0-6-0DE has already successfully demonstrated itself by then.

But as has been said before the diesel shunters simply couldn't do the work that the pannier tanks did. The 350hp diesels were dedicated shunters and that wasn't a type the GWR built in any numbers. When you do an analysis of the design its evident that the GWR pannier tanks, and especially the 94s and 15s,  had very large boilers compared to pure shunting classes like the Austerity and the S100, because they worked traffic as well as shunting.  In the event that short haul trip work largely disappeared but hard to predict that in 1947.

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5 minutes ago, whart57 said:

Well early 20th century reboilering, the O1s were hardly "modernised".

 

They were modernised in the sense of being brought up to the condition of locomotives that were being newly-built to do similar work - i.e. the Class C 0-6-0s. One has to consider what "modern" meant at the time, rather than applying an anachronistic standard. 

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I'm still wondering what that nice 2-6-2 was for. If its boiler makes it more powerful than a 4F, but presumably less than an 8F 0-8-0, is it a new need for a 6F with a lighter axle loading than a Black 5 (which are listed as BR Route Availability 7). This would pull heavier secondary freight on secondary lines.

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2 minutes ago, Compound2632 said:

 

They were modernised in the sense of being brought up to the condition of locomotives that were being newly-built to do similar work - i.e. the Class C 0-6-0s. One has to consider what "modern" meant at the time, rather than applying an anachronistic standard. 

 

The Wainwright C was not really "modern" either, it was just a slightly bigger LCDR B2. The main difference between the O1 and the O it was made from was the Stirling family fetish about domeless boilers. Once Stirling retired that feature was never going to be retained when his locos came to needing new boilers. "Modern" freight for the SECR would have been locos Ashford sketched out but never got permission to build, namely an 0-8-0 and an 0-6-2T. The latter would have been particularly useful on all the local freight runs in SE London, but with so many older 0-6-0s available and crews accepting the discomforts of tender-first running the business case wasn't there.

 

But to come back to imaginary locos, what about a tank engine variant of the Fowler 4F, an 0-6-2T 4F?

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On a tangent, the BR Standards were for the gap between the politicians representing coal mining constituencies (and faced with horrendous balance-of-trade issues) making the strategic decisions, and the countryside MPs deciding that the results of this are unaffordable. BR Standards then are an attempt to make the best of an expected extra 20 years of steam across a new, huge, bickering, organisation. And then getting a new strategy in 1955!

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