Collett 31xx; hostilities recommenced...

[The Johnster]

As some of you might recall, last year I involved myself in an attempt to build a 00 Collett 1938 31xx large prairie from various RTR and kit bits and old bodies.  The Collett 31xx is a bit of an obscurity, so for those of you who aren't familiar with the confusing story of GWR large prairies, here is a potted summary...

 

The GW large prairies were originally devised by that nice Mr Churchward back in 1906?, and came in two basic sizes, a 31xx class with a no.2 standard boiler and a 3150 class with a no.4.  By the time of this loco's introduction the 31xx had all been rebuilt to conform to Collett's 5101 design, of which new examples were in production as well, leaving the number series vacant.  Collett had already built the 61xx, a no.2 boiler variant with higher pressure but identical to the 5101s in appearance, and the 81xx. a further version with 5'6" diameter driving wheels as well as the higher pressure boiler for the hillier routes of the West Midlands. 

 

The original 3150s, meantime, had settled into a role as bankers and pilots, and were used for short haul transfer freights and such.  Collett, no doubt encouraged by the success of the 61xx, had a go at rebuilding a batch of them as his 1938 31xx class, the ultimate large prairie with no.4 boiler, higher pressure, and 5'3" driving wheels, bit of a beast.  Only 5 were converted from 3150s, though the intention was to rebuild the entire class to this specification.  In the event, the war intervened, Collett retired, and Hawksworth was happy to leave the rest of the 3150s alone.

 

We now come to 3100, doyen of the class, and my prototype, appropriate for Cwmdimbath as it was allocated to Tondu in 1946 for the post-war resumption of the daily 'Residential', the Porthcawl-Cardiff commuter train that had been a Bulldog job before the war.  The loco's smaller driving wheels and big, high pressure boiler gave it the desired edge in pulling away from the main line stops smartly with the 5-coach train and keeping out of the way of the faster stuff on the SWML.  It did this job, works vistis apart, until a 'heavy contact' with the buffers at Porthcawl in 1957 led to it's withdrawal from traffic and sending to Swindon for damage assessment, and the decision was taken to scrap it; the other 4 were scrapped over then next 3 years so it's time was probably up anyway.  It was replaced at Tondu by 4144, which is happily still with us...

 

A loco normally used on the Residential would be a rare sight up that the top end of the Tondu valleys, but I have seen a photo of it at Abergwynfi, and reckon it's worth a go.  It's an odd loco, a normal large prairie at first sight, but you very quickly realise that something's wrong with that analysis, the proportions are all askew, the smaller wheels make the rest of the loco look bigger but the general proportions are more like a 4575, and you have to do a bit of a double take.

 

My attempt at 3100 was not the most successful bit of modelling I ever did.  It was never going to be be any sort of scale model, a representation at best, and the original concept was to use the chassis block, cyldiners, and pony/radial trucks of an old Airfix 61xx with the boiler from an old Mainline 43xx and tanks/cab/bunker from an old Mainline 56xx.  Wheels would be Markits replacements, and the original Airfix keeper plate and pickup were to be used. 

 

It worked after a fashion, but not for long and I found it impossible to achieve reliable pickup with no short circuits, and ran into problems with the Airfix slide bars which kept breaking.  I decided to reitre from combat for a rethink, and then got distracted with building a colliery.  So now I am taking up cudgels again...

 

I decided that what was needed was an RTR chassis with the correct wheel spacing and 5'3" driving wheels.  Two are available, the Bachmann BR Standard 3MT 2-6-2T, 82xxx, and the Bachmann LMS Ivatt 4MT mogul.  I found an Ivatt mogul on the Bay of E, and am proceeding with this as the basis of the model.

 

Progress so far; it was from the outset clear that a fair amount of brutality would be needed to get the hybrid Mainline body to sit on the Ivatt mech.  Destruction of this sort goes against the grain, I like Ivatt 4MT moguls, and the Baccy is a fine model of this distinctive beast, but needs must!  I dismantled the Ivatt down to the bare chassis block and marked it up ready for cutting when the colliery project intervened; this was last November.  Last Friday I took it out of it's project box and emptied the bag of parts for a looksee, and started with the hacksaw.  2mm off each side of the sub-footplate at the rear of the chassis block, to enable it to fit inside the 56xx body, and cutting off the front of the block entirely as far back as the rear of the smokebox.  Poor, stunted, little thing!

 

As of yesterday evening, the wheels are back in and the motor has been refitted in it's cradle and on to the block.  Try-fitting the body has shown that there is clearance, but some material had to be removed from the inside of the 43xx firebox, at the top, for the motor to sit comfortably.  I will need to source suitable cylinders and motion, perhaps Hornby 5101, and devise mountings for the body tht will enable it to sit at the correct height.  Onwards and upwards!

[DCB]

Great news, I shall follow your progress with interest.   The Collett 31XX was an accountancy fiddle according to KJ Cook's book, the increased tractive effort justified the cost of the rebuild allowing it to be charged to capital or some such as it would be more suitable for banking.   Sadly the extra oomph made them prone to slipping which was the last thing you wanted for banking.  Local passenger however, well lets say the LNER would have been better off with 100  of the  31XX  than with their L1s.

Sadly I have a K's 43XX Boiler, an Airfix 61XX chassis on order and various 61XX parts so you have sadly caused me to restart my 3150 project .  This could end badly.   Keep up the good work.

[The Johnster]

It lives!  A bit of work this evening has got the motor wired up and a basic test run completed.  So far at least it is running very smoothly.  I have replaced the feed wires to the motor as the Bachmann ones are a bit flimsy and clearly not designed with the sort of handling they would have had to endure during this project, and have not replaced the DCC ready circuit board as there is no need for such sophistication at Cwmdimbath (I've no objection to DCC but can't afford it).  I am now going to have a think about the cylinders, slide bars, and motion; nothing of the Ivatt motion is suitable although it is the right size, must be plain not fluted fishbelly coupling rods though I may be able to get away with the Ivatt conrod.

 

Plenty to do on the bodyshell, as the 43xx front end is too long for a tank loco, and the dome above the pony truck should be half obscured by the curved running plate between the front and the main piece over the cylinders, for that's how we do things if we are GW large panniers.  The drop must be reduced as well, by about scale 2.5", to account for the lower 'sit' of the loco on the smaller driving wheels while maintaining the correct buffer height.  It doesn't sound much but if this model is to be convincing even within the boundaries of the 3 foot rule despite it's undoubted anomalies, at least the odd proportions of this class must be evoked.

[melmerby]

The original 3100 was built in 1903 as 99 in the prototype numbering sequence, it was renumbered 3100 in Dec 1912, became 5100 in April 1929.

As 5100 it had quite a few differences from it's days as 99, the true 5101s were not identical to it.

 

As you say, the GWR's 2-6-2T tanks have a complex & confusing history.

Just to confuse things more 3101-10 were small wheel (4' 1¼") tanks following on from prototype 115 from 1904. (they were built around the same time as the first production series of 31XX) .All were later renumbered 4400-10.

 

Edited April 27, 2022 by melmerby

[The Johnster]

Yes, the GW prairies are probably the most confusing group of classes, with small prairies with 4'1" wheels (another piece of Tondu esoterica), large prairies with no,2 boilers and 5'8" wheels, and large prairies with no.4 boilers and 5'3" wheels all using the 31xx number series at different times, some of the second type being converted over works visits as 5101s with outside steam pipes and the curved running plate drop at the same time brand new 5101s were being built as well, and after the visually identical 61xx (there is no visible difference in having a higher boiler pressure) production had begun.

 

The no.4 boilered large prairies, the 3150s, from which 'my' 3100 was rebuilt, acquired visual similarities to the 5101s over works visits in the form of the curved drop to the running plate ahead of the smokebox and outside steam pipes, and some outlasted the 'new' Collett 31xx. 

 

Panniers can be pretty confusing but at least the numbers help a bit!

Edited April 28, 2022 by The Johnster

[The Johnster]

Very basic general guide; 3 types of Churcward prototype, small with no.3 boiler and 4'1" driving wheels, large with no.2 boiler and 5'8" driving wheels, and large with no,4 boiler and, also. 5'8" driving wheels.  Note that these boilers and driving wheels, as well as the cylinders, were all standard Churcward components

 

The first type settled into being the 44xx, of which 11 were built, before it was decided that the locos would be more useful with 4'7" drivers (another standard Churchward size) and were continued as what eventually became the 45xx class, of which 75 were built, followed by the 4575 class with enlarged tanks.  Some 4575s were fitted with auto gear in 1953 in connection with the introduction of a new timetable in South Wales that increased the number and loads of auto services in that area.

 

The second type became the original 31xx, which was eventually developed into the 5101 class, all the original locos being rebuilt to 5101 specification and included in that class along with brand new locomotives.  At around the same time, Collett brought out the 61xx, visually identical to the 5101 but with increased boiler pressure for the London area suburban services where faster accelleration was needed.  A development of this was the 81xx, higher boiler pressure and 5'6" driving wheels for the Birmingham area.  The 81xx represents a departure from Churchward standard driving wheel sizes (and one 61xx was given 5'6" driving wheels as an experiment in this class's development, which it retained until withdrawal).

 

The third type became the Churchward 3150 class, which was more or less left in original condition except for curved running plates at the front and outside steam pipes, until 1938 when 5 of them were rebuilt to the Collett 1938 design, 'my' engine.  The 1938 31xx engines also represent a further departure from Churchward standard driving wheel sizes.

 

The 44xx and 45xx were of yellow route availability.

The 4575, Churchward 31xx/Collet 5101/61xx/81xx classes were of blue route availability. 

 

The 3150 and Collett 1938 classes were of red route availabily. 

 

All the GW prairies were classified as power class 4MT by BR.

 

4mm RTR and kits as follows:-

 

44xx was available as a whitemetal kit from Keyser many years ago.

45xx is available RTR from Bachmann

4575 is available RTR from Bachmann and previously from Lima.

 

31xx (Churchward) has never been available in RTR or kit form.

5101 is avialable RTR from Hornby and Dapol, also as a previous tooling based on the Airfix 61xx from Hornby.

61xx is available RTR from Hornby and Dapol as the same toolings as the 5101, and previously as an Airfix-based tooling from Hornby, and previously to that from Airfix

81xx was availlable many years ago from Graham Farish.

 

TTBOMK the 3150 and Collett 1938 31xx classes. my 'third type' with the no.4 boiler, have never been available in RTR or kit form in 4mm.  The 3150 must be one of the lowest hanging fruit GW steam locos left for potential RTR production.

Edited April 28, 2022 by The Johnster

[Steamport Southport]

Quite a few kits missing from that.

 

41XX/51XX/61XX - Wills/SE Finecast (now Squires)

41XX/51XX/61XX - Brassmasters (ex Finney)

3150 - Brassmasters (not yet available) 

 

41XX/51XX/61XX - PDK

81XX - PDK

31XX - PDK

51XX (Straight Frame) - PDK

 

The various PDK models are here. Notice the differences.

 

http://www.pdkmodels.co.uk/Gallery 3.html

 

44XX - Malcolm Mitchell

44XX - Falcon Brassworks

45XX - K's/Nucast

45XX - Malcolm Mitchell

45XX - Falcon Brassworks

45XX - Churchward Models (Phoenix)

4575 - K's/Nucast

 

39XX - Jackson Evans (never seen one but I expect Phoenix have it)

 

 

 

Jason

[The Johnster]

Information useful, Jason. 

 

I included the Keyser 44xx in the list as TTBOMK that was the only one ever avaialble, not being aware of the Mitchell or Falcon kits.  Old K's 44xx turn up on the Bay of e sometimes, and while the body castings are reasonable for their era, the chassis always look pretty hopeless.  Incidentally neither the Mitchell nor Falcon 44xx are currently available and I have learned to be cynical about the future availability of such items.  The Falcon looks good value for the money and I'll keep an eye on it, though; these locos were allox TDU to work the sharply curved Porthcawl branch until it went over to auto operation in 1953, and if 3100 (also associated with Porthcawl) got up to Abergwynfi a 44xx might well have found it's way up into the mountain fastnesses as well, under the authority of Rule 1...

 

I think the Finney is probably a bit out of my comfort zone, though they are beautiful models if made up properly.  I am guessing that the PDK 31xx is a kit for the Churchward loco, with no.2 boiler and 5'8" drivers, not 'my' Collett 1938 31xx...

[The Johnster]

Back to 3100; sitrep is that I have a running chassis that works with the axles in the right place and with the right sized driving wheels, yay me!  They may not have the right number of spokes, haven't counted but there is not much I can do about this and I will live with the situation as it is, so I don't really want to know...  So, what's next?

 

Next will be cylinders, slide bars, and motion.  I am not working properly, side effects from a new medication, and staying in today, so I thought a good way to waste the time would be to investigate the sourcing and availability of these items while The Squeeze feeds me tea and biccies at regular intervals; there are worse ways of being ill...  So far, I've had a look at Comet parts and tried to suss out Hornby Spares.  Comet costs out at about £25 inc. p%p but of course requires building, always a risk that I'll mess it up. while I cannot find where on the Hornby website the spares are. so am assuming Hornby don't do spares any more.  Might be worth giving them a ring on Monday to see if they can help, but I'm not holding my breath! 

 

Next move was Peter's Spares, which can provide me with a cyldinder block and slide bar assembly, actually intended for a 42 but should be ok grafted on to 3100, thanks to Mr Churchward's standard sized bits.  Looks like a cromulent way forward in conjuntion with Comet motion brackets, crossheads, conrods, and coupling rods, so orders going in soon.  I am taking a bit of a punt on the Comet crossheads sliding happily on the Hornby slidebarsBut before I commit to this, it might be worth looking at what came with the Ivatt, to see if the slide bars and crossheads can be used on 3100 without further compromising the look, and it is possible that the conrods might be re-usable as well.

 

The original intention was to do this to a budget of about £60, but that is a ship that has long sailed, hit the iceberg, sunk, been salvaged, sailed again, hit another iceberg, and sunk again.  Estimated costs at the moment are going to be about £140,, given what's already been spent, about the same as a new RTR large prairie from Hornby or Dapol that would arguably be more suitable for Cwmdimbath in the first place, and I'm going to have to be careful that my determination not to let the project beat me doesn't escalate.  If this attempt to build a working chassis with outside cylinders and motion that looks a bit like 3100's doesn't come off, I'll probably call it a day. 

 

This is because of course there are other sources of cylinders and motion possibly avaialble; I think Southeastern are amenable to selling individual parts of the old Will's range.  But I'm nearing the limit of what I'm prepared to spend on having a 3100 on Cwmdimbath, a loco  that would only have been a very occasional visitor to such a place anyway. 

 

I'll be having a running session later this evening, and will play around with the Ivatt bits to see if anything can be used.

[The Johnster]

Ok, so there has been some progress, but I've learned a bit more about why trying to make a Collett 31xx out of an Ivatt 4MT running chassis and a few other bits is a daft idea.  Firstly, I've made a bad mistake in my assumption that the axle spacing of a GW large prairie is the same as the Ivatt's; it isn't.  I checked it, or thought I did, when I was investigating the idea and line the Ivatt up with my Hornby 5101 when I got it, and all seemed fine, but I should have double checked and looked closer.

 

This means that there is no point in continuing unless I am to use the Ivatt coupling rods.  I can work these up a bit to make them look less unlike GW fishbellies I suppose, perhaps filling the flute with Milliput and filing down at the ends to make the bellies.  Or perhaps thin card overlays.  I've also discovered, or perhaps rediscovered after I'd forgotten, that the Ivatt's leading pony wheels are too small, not the end of the world and I may have something in the scrap box that will do the job.

 

But the connecting rods, with the crossheads and piston rods, will do; not perfect but of course it's too late to claim that this is going to be a scale model rather than a general impression anyway!  Progress is that I've temporarily mounted the coupling rods and now have a working 0-6-0 chassis.  If luck is on my side, the Peter's Spares 42xx cylinder block will work with it's slidebars (the Ivatt's are nowhere near) and the only thing left to find then will be the motion bracket; again, the scrap box might come up trumps.

[The Johnster]

22 hours ago, The Johnster said:

Estimated costs at the moment are going to be about £140,, given what's already been spent, about the same as a new RTR large prairie from Hornby or Dapol that would arguably be more suitable for Cwmdimbath in the first place,

 

Belay that last order!  Just had a browse through the Hornby online cataloge to find that their large prairie is now running at nearly 30 beer vouchers more than this!  Still hoping to keep costs down, but thinking that I might be better served by writing off what I've already spent and opening a new ledger for this project, otherwise the previous disaster (loss of a Hermes delivered Ivatt chassis, photographed hidden behind bin but not there when I went outside, so presumably stolen by one of our friendly neighbourhood druggies, isn't the inner city fun, £40 up the shoot and another 50 to replace it with the currently destroyed Ivatt) will influence my future spending on the project. 

 

But I'm already in posession of most of the components, so finishing off the model consists of completing the chassis to a tolerable standard (cyldinders, slidebars, motion brackets, new pony still outstanding), and a bit more work on the bodyshell, particularly replacing the curved dropframe ahead of the smokebox which a stupid person thought was the same as the Mainline 43xx, but handrails, buffers, and the like.  So it shouldn't cost me too much more, touch wood.

 

There is a danger in this of course, that small items mount up.  If you put an arbitrary cap on the project, say another £50, what happens when you've spent £45 and need to order a set of buffers and a Modelu crew that comes to about £20 to finish off.  I'm at the point that I don't want to abandon the project, not just because it would be admitting defeat and having to cope with the impact on my mental health of 'yet another predictable failure', but have spent too much already to write off without any result, and my current attempt at budgeting is really only trying to limit the extent to which good money chases bad.  I should consider this projece when I criticise NR for the GW electrification overspend! 

 

Orders of multiple items at the same time from individual sources to economise on postage and delivery charges will mean the sort of forward planning that is not my strongest point, and my drip-feed pension payments can mean that I have to place orders for single items and wait until next pension day for the next one on the list, which is false economy but difficult to avoid; saving up 'pocket money' is vulnerable to the saved amount being diverted to other purposes!  Those living on small fixed incomes will understand...

[DK123GWR]

2 hours ago, The Johnster said:

There is a danger in this of course, that small items mount up.  If you put an arbitrary cap on the project, say another £50, what happens when you've spent £45 and need to order a set of buffers and a Modelu crew that comes to about £20 to finish off.  I'm at the point that I don't want to abandon the project, not just because it would be admitting defeat and having to cope with the impact on my mental health of 'yet another predictable failure', but have spent too much already to write off without any result, and my current attempt at budgeting is really only trying to limit the extent to which good money chases bad.  I should consider this projece when I criticise NR for the GW electrification overspend! 

 

It's not often that I advocate first year economics textbooks as a source of practical life advice, but I it might help here. According to economic theory, you should decide whether you're going to spend more money on the project based purely on:

1) How much closer to finishing the project to a standard that will please you that spending will bring you

2) Whether there is anything else that you can do with the money which would bring a greater benefit

 

There is no point in considering what has been spent already when making an investment decision (whether that's about parts to build a model locomotive* or work to electrify a full-size railway). These sunk costs are beyond your control, and do not affect the value of future spending. To try and illustrate the point: suppose that I am in the middle of developing a machine which I expect will earn me £1 per day once complete. Now, I realise that if I build a different machine, it will earn £1.05 per day. I should be able to finish the first machine or build the second by spending £50. Obviously, I should (at least temporarily) abandon the first machine and build the second. The fact that I have spent £200 on it already is irrelevant - I can get the best return to the money that I have available to spend now by building the second machine. Of course, it might be that once I have done this, and have more money available to spend again, it makes sense to return to the first machine (if this is now the most profitable use for the money).

 

The first machine is like your 31xx - so long as you think spending on the 31xx is the best value you can get from your modelling budget, this is what you should do. If that changes, because you find a better use for the money (as you did with the colliery) then spend money on that. Suppose that tomorrow an RTR manufacturer announces a 31xx. So long as the expected cost to finish your model is less than the price of the RTR model, plus the value that you place on the 'I built that' feeling, less the value that you place on the amount by which the expected quality of the RTR model exceeds the expected quality of your model, then your should continue with your model. If the anticipated cost of finishing your model becomes greater than this, it would be irrational to do anything except buy the RTR model, despite the money you have spent already. You could apply parallel reasoning to any other competing demand on your budget.

 

Lecture over. Feel free to ignore it - most people won't have read past the first line anyway. Apologies if we have any experienced economists on the thread who feel that I've gotten it terriby wrong. (Whether you are or not, some experienced economist will always tell you you're wrong - unless you're stating the principle of comparative advantage, which is one of the very few things that they all seem to agree on**).

 

 

 

 

*Yes, I know that spending on model railways will be counted as consumption, but I am modelling it as an investment one, where a working locomotive will provide a certain amount of utility (pleasure, to normal people) each day, which has an approximate financial value

 

**This is not an invitation to prove otherwise - we are supposed to be discussing toy trains after all. This is still as close as you'll come to finding something uncontroversial

[1466]

3 hours ago, The Johnster said:

 

Belay that last order!  Just had a browse through the Hornby online cataloge to find that their large prairie is now running at nearly 30 beer vouchers more than this!  Still hoping to keep costs down, but thinking that I might be better served by writing off what I've already spent and opening a new ledger for this project, otherwise the previous disaster (loss of a Hermes delivered Ivatt chassis, photographed hidden behind bin but not there when I went outside, so presumably stolen by one of our friendly neighbourhood druggies, isn't the inner city fun, £40 up the shoot and another 50 to replace it with the currently destroyed Ivatt) will influence my future spending on the project. 

 

But I'm already in posession of most of the components, so finishing off the model consists of completing the chassis to a tolerable standard (cyldinders, slidebars, motion brackets, new pony still outstanding), and a bit more work on the bodyshell, particularly replacing the curved dropframe ahead of the smokebox which a stupid person thought was the same as the Mainline 43xx, but handrails, buffers, and the like.  So it shouldn't cost me too much more, touch wood.

 

There is a danger in this of course, that small items mount up.  If you put an arbitrary cap on the project, say another £50, what happens when you've spent £45 and need to order a set of buffers and a Modelu crew that comes to about £20 to finish off.  I'm at the point that I don't want to abandon the project, not just because it would be admitting defeat and having to cope with the impact on my mental health of 'yet another predictable failure', but have spent too much already to write off without any result, and my current attempt at budgeting is really only trying to limit the extent to which good money chases bad.  I should consider this projece when I criticise NR for the GW electrification overspend! 

 

Orders of multiple items at the same time from individual sources to economise on postage and delivery charges will mean the sort of forward planning that is not my strongest point, and my drip-feed pension payments can mean that I have to place orders for single items and wait until next pension day for the next one on the list, which is false economy but difficult to avoid; saving up 'pocket money' is vulnerable to the saved amount being diverted to other purposes!  Those living on small fixed incomes will understand...

I’ve been there with second hand cars . I couldn’t afford a new one and then had to spend out on a new starter. Then the gearbox went and suddenly I’ve spent more than a new car on my second hand one ; but I’ve invested so much I can’t sell and buy a new one .

Keep at it , Johnster !

[The Johnster]

1 hour ago, DK123GWR said:

Lecture over. Feel free to ignore it

 

I'm not going to ignore it, it's clearly very good advice.  And I read through the lot, not just the first paragraph.

 

1 hour ago, DK123GWR said:

So long as the expected cost to finish your model is less than the price of the RTR model, plus the value that you place on the 'I built that' feeling, less the value that you place on the amount by which the expected quality of the RTR model exceeds the expected quality of your model, then your should continue with your model.

 

Clearly, this being the case, I should continue with my model, and will do so, and it also being the case that I'm enjoying it, the model will be duly continued.  There is no RTR nor current kit available for this particular prototype, and though a kit is in the pipeline I've learned to be wary of kit promises.  The chances of an RTR model during my lifetime are pretty low given that the 3150 is still in the in tray, so the quality that my attempt fails to match the RTR by is irrelevant; the only way I can have one is to either build it up out of 'more or less' bits as I am doing, or to scratch build, which I'm not sure I could manage at my time of life...

 

The question then reverts to the original one from the start of the project, 'do I want a model of 3100 on Cwmdimbath'?, and the answer is 'yes'.  If the question is, in the O level economics sense that I vaguely understand it, 'do I need a model of 3100 on Cwmdimbath'?, the answer is much less certain and is somewhere between 'probably' and 'probably not'.  A Tondu locomotive during my period that was photographed in 1950 at Abergwynfi, but mostly used on the Porthcawl-Cardiff 'Residential', it's a possible rather than probable engine to have turned up at Cwmdimbath, an actual side valley off the Ogwr Fach just north east of Glynogwr on the way to Hendreforgan that was never in reality home to a colliery branch or village.  There was at one time a tramroad connecting to a presumably water powered forge about where my village would be, hence the pub being named 'The Forge'.

 

Any uncertainty is the result of my knowing that I can have a perfectly satisfactory Cwmdimbath without 3100, or for that matter the possible 44xx future project.  I can't without a 57xx, 8750s, 4575s, 56xx, 42xx, 94xx, and I'd seriously miss my 5101 if I didn't have it; I work to the principle that if it was photographed at Abergwynfi, Blaerngarw, or Ogmore Vale it showed up at Cwmdimbath.  These are classes I regard as essential, or very nearly essential in the case of the 5101 (only photographed on the Abergwynfi and Porthcawl branches).  3100 and 44xx are possibles with the 44xx perhaps less likely, and a Neath Court Sart BR 4MT 2-6-4T transferred from Paxton Street found it's way to Blaengwynfi with an excursion from Porthcawl in 1963, but that's pushing things a bit too far for me so I'm not going to include one of those!

 

Your 'lecture' points out that the money and effort I've already spent on the project prior to the colliery distraction is pretty much irrelevant to the current sitrep.  Should another distraction show up, I will re-assess the situation on whatever basis seems best at that time, but for now, my decision, thanks in no small measure to your sensible advice but tbh the way I was heading anyway, is to carry on to completion in whatever way presents itself on pension days.  An order for a 42xx cylinder block/slide bars assembly will go in to Peter's next pension day, Wednesday week, and the interim period will be used in examining ways of completing the bodyshell and sourcing motion brackets.

 

When the cylinder block arrives, I will work on ways to graft it to the front end of the truncated Ivatt chassis block, mount the connecting rods to the centre drivers and the attached crossheads to the slide bars, and hopefully do some successful test running even if some fettling is needed to get things smooth.  There is therefore now a plan, a set course of future further action to be taken, which feels a lot more positive than 'should I this or should I that'?  This is important, because a plan confers a sort of momentum to project that will help it overcome obstactles and become a self-fulfilling prophesy.  The job seems impossibly massive, but is really a sequence of smaller and achieveable bite-sized projectettes to be ticked off before the next one is begun. 

 

So, all being well, I should have a new loco on Cwmdimbath in 2 or 3 months that has not been hard to pay for and looks to my jaded eyes at least a little bit like 3100!

 

 

[DCB]

Is there any way you could use Ivatt driving wheels in a 43XX Mogul chassis?    A 3150 would be so much easier!   That said mine isn't getting built.

You could continue with the 44XX.  The Bachmann 45XX body looks like the best basis, the K's (I have a K;'s 44XX Body on eBay if anyone wants a nice body?)  Has a short bunker and long smokebox, I am not sure more than one (4405?) ran like that certainly not in my BR era and needs major surgery (Mine is GWR Green and too nice to carve up!). The Bachmann 45XX essentially needs front and rear buffer beams shortened and new number plates.  Chassis wise the 10 spoke 4ft 1" wheels  (OK one ran with 12 spoke) are a nightmare even if you can accept the front and rear wheels being too far back...

Best of luck with the 

[The Johnster]

A 3150 would be much easier, basically any Airfix or Hornby or Dapol large prairie with tbe boiler replaced by a no.4, but Tondu never had any 3150s; come to that, they only had the one 1938 31xx, 3100.  Using a 43xx chassis brings in some of the problems from my initial attempt with an old Airfix 61xx chassis; the running plate sits too low and has to be raised, but without leaving too obvious a gap between the top of the cylinders and the bottom of the running plate.  The height of the cylinders is critical and the centre line of the piston rod must horizontally intersect the centre line of the middle axles, absolutely essential to the appearance of any GW outside cyldinered engine even in such a lo-fi attempt as this.   

 

Which 43xx did you have in mind, DCB?  The obvious choice in terms of cost would be a 2h Mainline, but this of course comes with a built in self-detruct mechanism and not a partiuclarly good slow running performance even when it is still working.  The Dapol would be too expensive, and the advantage of the Ivatt is that it is a running chassis, nice smooth performer to boot, with the correct size driving wheels and axle spacing that is not far off.  I initially thought it was identical, but there is enough of a difference to prevent smooth running with Airfix coupling rods...

 

I'm thinking about the possibility of a 44xx based on the Baccy 45xx.  This is much less fraught than 3100, and would be a breeze in comparison.  You could use pretty much all of the 45xx except for the wheels, and the buffer height is not the problem it might initially appear, as the height discrepancy can be solved in exactly the way that Churchward solved it; remove the buffer beams, turn them upside down, and replace them...  After that the problems begin to stack up, though.  You've mentioned the wheels, and on this loco the spokes are particularly distinctive, a feature that must be got right, but the biggest problem is that, because the tanks sit lower on the lower frames, the boiler appears to stick up more from them, again something essential to the 44xx look and requiring considerable mangling of the Bachmann 45xx bodyshell.

 

Tondu's 44xx during my period were 4404/6/8, not all at the same time and all gone by 1954, the Porthcawl branch which provided their main work because of the very sharp curvature have 'gone over' to auto working in September 1953.  There were 2 at any given time, backed up by 4557 as a reserve, and worked a passenger and a freight diagram, the latter including servicing a limestone quarry as well as the daily pickup.  Curvature was such that the locos, which both came back to Tondu at lunchtime for crew relief, were turned to even out flange wear.  I have no evidence that any of them ventured beyond the Tondu-Porthcawl-Bridgend-Tondu routes, and they would in fact have been less suitable for the Valleys branches than 4557 or the 4575s (which hauled 'normal' stock as well as autos). 

 

This would be for the same reasons that apparently led to the redesign to 45xx specification in the first place, the 4'1" drivers proving too slow for even the usual type of branch work and increasing steam, and hence water consumption and, to a lesser extent, coal consumption over a given distance.

 

Is that your 4405 for £28 part built?  Tempting, I've got some Baccy 45xx bits in the spares box, might make a worthwhile project, let me do some sums a minute...

 

**** it, you're only young once, I've been and gorn and bought it!

 

3100 project on hold for the time being, project is now 44xx and I will start a new thread. 

 

 

 

 

Edited May 2, 2022 by The Johnster

[The Johnster]

For some odd reason I posted the new thread over on UK Prototype Questions, senior moment again.