Johnster's 44xx

[The Johnster]

Came over me all sudden like, it did...

 

Those who have been following my 31xx adventure will realise that this is a follow-on thread to that one, which contains the story of how a reasonably priced 44xx came to my attention today and provided me with a fighting chance of a decent model of this distinctive little engine at Cwmdimbath.

 

To fill in on the prototype, a GW 44xx is the doyen of Churchward's 'small prairie' classes, of which the 45xx and 4575, available RTR from Bachmann, are better known.  They were better known as real engines as well, as the total class numbers of 45xx were 75 locos and there were 100 4575s, but only 11 44xx.  On first sight of a 44xx, you think you are looking at a 45xx, but something's wrong, and you quickly realise it's the driving wheels; small on the 45xx and 4575, 4'7", they are tiny on a 44xx, 4'1", the only use TTBOMK of wheels as small as this on a Churchward outside cylindered locomotive, except perhpas 101.  The smaller driving wheels meant that there were other differences; the buffer beams were mounted the other way up, with the buffer shank centres nearer the top, and because the top of the cylinders was made lower by the piston rod centre being horizantally level with the driving axle centres, the running plate was a little lower, which in turn meant that the tanks which rested on top of it were corresepondingly a little lower, meaning that the boiler and firebox protruded more from the top of the tanks and made the loco look even more 'gawky' and top heavy than the more familiar 45xx; the whole effect is out of proportion and awkward.  There's more to making one than replacing the wheels of a Baccy 45xx...

 

They were intended for branch line work, but only 11 were put into service before it was apparent that the driving wheels could not comfortably provide enough speed for even branch duties, resulting in the rethink with 4'7" wheels that gave us the 45xx.  When they were originally produced, they were numbered in the 31xx series, later to be used by the large prairies for two completely different classes as has been seen in my 3100 thread.  The 11 found a niche, however, the short coupled wheelbase and small diameter wheels being ideal for routes where severe curvature and flange wear was a feature.  They settled in to work on the Princetown, Much Wenlock, and Tondu-Porthcawl branches, all notable for sharp curvature.  On the Porthcawl branch, the curvature was so severe that they were only locomotives not speed restricted to 5mph on the tightest curves (this route was converted, though not all that much, from a tramroad), and it was practice to turn them half way through each day's diagram when the crews were changed at lunch time to even out flange wear. 

 

Tondu had 2 at any given time, backed up by a 45xx to cover washouts and works visits, which busied itself on other Tondu jobs when Porthcawl work was not required of it. During my period this was 4557.  There were 2 44xx diagrams, Tondu-Porthcawl passenger and Porthcawl branch pickup goods, which handled passenger traffic later in the day as well.  One working was an evening Porthcawl-Bridgend, which meant that the locos appeared there and between there and Tondu as well.  Locos that spent time at Tondu during my period (nominally 1948-58) were 4404/6/8, not all at the same time. 

 

Of those, so far as I can determine from photographs, 4406 and 4408 had outside steam pipes, and I have a choice of liveries.  4404 had unlined green early BR with 'BRITISH RAILWAYS' on the tank sides in GW-style Egyptian Serif lettering, which must have been recently applied, in late 1948, but had been repainted in plain black with no insignia by 1951.  4406 had plain black BR livery with a unicyling lion totem in 1954 (it was the last of the class at the shed) and very probably had this in a less certainly clear 1952 photograph as well.  4408 was plain black with no insignia, smokebox or buffer beam number. or shedcode plate in 1951.  The understudy, 4557, also carried a plain black livery with no insignia (though it did carry smokebox number and shed code plates) while it was at TDU; it was xfer Narberth in 1954 and may have carried this livery there as well, but was repainted in LNWR style lined black BR mixed traffic style livery with a unicycling lion later on.  My main source of photos are the John Hodges/Stuart Davies 'Tondu Valleys' books.

 

I actually already have 4557, a Bachmann with Modelu crew and a plain black repaint.  Late 1948 4404, in unlined green with Egyptian Serif lettering, would be my fisrt choice, for the unusual livery and the lack of need to bother with steam pipes.  We'll assume the model will be of 4404 for now...

 

Moreso even than 3100, which at least got itself photographed at Abergwynfi in 1950, 4404 is a Rule 1 loco.  It is not completely impossible that it might have found it's way into the mountain fastnesses that include Cwmdimbath, but it's not something I know to have ever happened, or was especially likely to ever have happened.  It's improbable, highly even, but not enough to prevent me invoking Rule 1.  It might have turned up on the pickup or even as a passenger loco covering for a failed pannier, but not with auto coaches, which didn't arrive at TDU until 1953, the event that sealed the fate of the 44xx on the Porthcawl branch.  And because of the practice of turning the locos at midday, and in fact sending them out for duty each day facing in opposite directions, there is no reason to stick to the 'smokebox leading up the valley' rule that was normal in South Wales work. 

 

Now to the model itself.  The K's kit is very much of it's time, especially the mech and the chassis.  My purchase comes with a motor and a flywheel, so might be a runner, but there is no detail below the running plate; no brakes, rodding, springs, nothing. and because the driving wheels are so small, it looks very bare down there.  If it runs, with Romford gears and a flywheel, it could potentially run very well indeed! The model will be a combination of Bachmann and K's parts with the K's bodyshell, but exactly what combination I have yet to determine.  It may be possible to graft the Bachmann keeper plate with the brake and spring detail on to the K's chassis, or it may be better to use the K's wheels as replacements in the Bachmann chassis; it will certainly be an advantage to use the Bachmann slide bars and motion from the point of view of the model's appearance; the K's attempt at slide bars is perhaps the weakest part of this kit and from photos it looks to be next to impossible to get them to stay parallel or level.  The whitemetal bodyshell, which is complete and painted in unlined green GW livery on the model I've bought, is well made and should give me no problems.  I'll probably hacksaw Bachmann buffer beams from the spare frame I have as they will be better detailed, then mount them upside down to get the buffer height correct, and use the Baccy buffers.  The Baccy smokebox and bunker rear might be better lookers than the K's as well, also the cab roof, not to mention the handrails.

 

 

 

 

[Miss Prism]

What makes you think this is in green?

 

 

[Paul H Vigor]

39 minutes ago, The Johnster said:

Came over me all sudden like, it did...

 

Those who have been following my 31xx adventure will realise that this is a follow-on thread to that one, which contains the story of how a reasonably priced 44xx came to my attention today and provided me with a fighting chance of a decent model of this distinctive little engine at Cwmdimbath.

 

To fill in on the prototype, a GW 44xx is the doyen of Churchward's 'small prairie' classes, of which the 45xx and 4575, available RTR from Bachmann, are better known.  They were better known as real engines as well, as the total class numbers of 45xx were 75 locos and there were 100 4575s, but only 11 44xx.  On first sight of a 44xx, you think you are looking at a 45xx, but something's wrong, and you quickly realise it's the driving wheels; small on the 45xx and 4575, 4'7", they are tiny on a 44xx, 4'1", the only use TTBOMK of wheels as small as this on a Churchward outside cylindered locomotive, except perhpas 101.  The smaller driving wheels meant that there were other differences; the buffer beams were mounted the other way up, with the buffer shank centres nearer the top, and because the top of the cylinders was made lower by the piston rod centre being horizantally level with the driving axle centres, the running plate was a little lower, which in turn meant that the tanks which rested on top of it were corresepondingly a little lower, meaning that the boiler and firebox protruded more from the top of the tanks and made the loco look even more 'gawky' and top heavy than the more familiar 45xx; the whole effect is out of proportion and awkward.  There's more to making one than replacing the wheels of a Baccy 45xx...

 

They were intended for branch line work, but only 11 were put into service before it was apparent that the driving wheels could not comfortably provide enough speed for even branch duties, resulting in the rethink with 4'7" wheels that gave us the 45xx.  When they were originally produced, they were numbered in the 31xx series, later to be used by the large prairies for two completely different classes as has been seen in my 3100 thread.  The 11 found a niche, however, the short coupled wheelbase and small diameter wheels being ideal for routes where severe curvature and flange wear was a feature.  They settled in to work on the Princetown, Much Wenlock, and Tondu-Porthcawl branches, all notable for sharp curvature.  On the Porthcawl branch, the curvature was so severe that they were only locomotives not speed restricted to 5mph on the tightest curves (this route was converted, though not all that much, from a tramroad), and it was practice to turn them half way through each day's diagram when the crews were changed at lunch time to even out flange wear. 

 

Tondu had 2 at any given time, backed up by a 45xx to cover washouts and works visits, which busied itself on other Tondu jobs when Porthcawl work was not required of it. During my period this was 4557.  There were 2 44xx diagrams, Tondu-Porthcawl passenger and Porthcawl branch pickup goods, which handled passenger traffic later in the day as well.  One working was an evening Porthcawl-Bridgend, which meant that the locos appeared there and between there and Tondu as well.  Locos that spent time at Tondu during my period (nominally 1948-58) were 4404/6/8, not all at the same time. 

 

Of those, so far as I can determine from photographs, 4406 and 4408 had outside steam pipes, and I have a choice of liveries.  4404 had unlined green early BR with 'BRITISH RAILWAYS' on the tank sides in GW-style Egyptian Serif lettering, which must have been recently applied, in late 1948, but had been repainted in plain black with no insignia by 1951.  4406 had plain black BR livery with a unicyling lion totem in 1954 (it was the last of the class at the shed) and very probably had this in a less certainly clear 1952 photograph as well.  4408 was plain black with no insignia, smokebox or buffer beam number. or shedcode plate in 1951.  The understudy, 4557, also carried a plain black livery with no insignia (though it did carry smokebox number and shed code plates) while it was at TDU; it was xfer Narberth in 1954 and may have carried this livery there as well, but was repainted in LNWR style lined black BR mixed traffic style livery with a unicycling lion later on.  My main source of photos are the John Hodges/Stuart Davies 'Tondu Valleys' books.

 

I actually already have 4557, a Bachmann with Modelu crew and a plain black repaint.  Late 1948 4404, in unlined green with Egyptian Serif lettering, would be my fisrt choice, for the unusual livery and the lack of need to bother with steam pipes.  We'll assume the model will be of 4404 for now...

 

Moreso even than 3100, which at least got itself photographed at Abergwynfi in 1950, 4404 is a Rule 1 loco.  It is not completely impossible that it might have found it's way into the mountain fastnesses that include Cwmdimbath, but it's not something I know to have ever happened, or was especially likely to ever have happened.  It's improbable, highly even, but not enough to prevent me invoking Rule 1.  It might have turned up on the pickup or even as a passenger loco covering for a failed pannier, but not with auto coaches, which didn't arrive at TDU until 1953, the event that sealed the fate of the 44xx on the Porthcawl branch.  And because of the practice of turning the locos at midday, and in fact sending them out for duty each day facing in opposite directions, there is no reason to stick to the 'smokebox leading up the valley' rule that was normal in South Wales work. 

 

Now to the model itself.  The K's kit is very much of it's time, especially the mech and the chassis.  My purchase comes with a motor and a flywheel, so might be a runner, but there is no detail below the running plate; no brakes, rodding, springs, nothing. and because the driving wheels are so small, it looks very bare down there.  If it runs, with Romford gears and a flywheel, it could potentially run very well indeed! The model will be a combination of Bachmann and K's parts with the K's bodyshell, but exactly what combination I have yet to determine.  It may be possible to graft the Bachmann keeper plate with the brake and spring detail on to the K's chassis, or it may be better to use the K's wheels as replacements in the Bachmann chassis; it will certainly be an advantage to use the Bachmann slide bars and motion from the point of view of the model's appearance; the K's attempt at slide bars is perhaps the weakest part of this kit and from photos it looks to be next to impossible to get them to stay parallel or level.  The whitemetal bodyshell, which is complete and painted in unlined green GW livery on the model I've bought, is well made and should give me no problems.  I'll probably hacksaw Bachmann buffer beams from the spare frame I have as they will be better detailed, then mount them upside down to get the buffer height correct, and use the Baccy buffers.  The Baccy smokebox and bunker rear might be better lookers than the K's as well, also the cab roof, not to mention the handrails.

 

 

 

 

I've always had a soft spot for the 44xx class. I have acquired several 00 models over the years in varying states of disrepair.

[Paul H Vigor]

16 minutes ago, Miss Prism said:

What makes you think this is in green?

 

 

A delicate shade of greeny gray?

[Marshall5]

I'm not sure how you can use the Bachmann 45xx chassis for the 44xx unless you can reverse it in the body.  The 44xx driving wheelbase is 6' 0" + 5' 6" whereas the 45xx is 5' 6" + 6' 0".

Ray.

[The Johnster]

1 hour ago, Miss Prism said:

What makes you think this is in green?

 

 

 

Good question, it's not definite by any means, is it?  But I think it's green, it looks like green to me, everything is covered in a light dust (ash, perhaps and bathed in sunlight, and I have seen more photos of green locos in this livery than black ones if that makes sense.  The photo is dated 28th August 1948, so the livery must have been applied between nearly 3 and nearly 8 months earlier.  My gut feeling is that the lighting is making the loco look dirtier than it actually is, and that if it was black there'd be more of a contrast between the lettering and the background.

 

I am going to take a punt on it being green unless definitive information to the contrary comes to light. in which case I'll repaint it but keep the Egyptian Serif lettering; sometimes you have to go with your gut feeling and keep your legs, I mean fingers, crossed; I can't state that it's black, either, and an executive decision is required...

 

1 hour ago, Paul H Vigor said:

I've always had a soft spot for the 44xx class. I have acquired several 00 models over the years in varying states of disrepair.

 

There is something appealing about them, isn't there, which is why the K's kit was disproportionatley popular for a class of only 11 locos that were never particularly well known.  They're sort of so ugly they come out the other side and are beautifully ugly!

 

1 hour ago, Marshall5 said:

I'm not sure how you can use the Bachmann 45xx chassis for the 44xx unless you can reverse it in the body.  The 44xx driving wheelbase is 6' 0" + 5' 6" whereas the 45xx is 5' 6" + 6' 0".

Ray.

 

Good point, Ray; I knew this but needed reminding.  As I say I'm not sure yet exactly what form this model will take. and I'm not yet sure it will be on a Bachmann chassis, but it will be a hybrid K's 44xx/Bachmann 45xx of some sort.  I will need to get the model in my sweaty paws and have a poke about/look see to see what I can do and how to do it  If the K's chassis runs well I'll keep it and use Baccy 45xx bits to improve the appearance, especially below the running plate.  This might entail using the Baccy keeper plate or chopping it about to provide brake detail, but of course the brake blocks will be a long way off the wheels, or not at the same centre if I move them in closer to the tyres.  I will almost certainly want to use the Baccy slide bars, and probably the cylinders, motion bracket, piston rod, crosshead, and connecting rod as well.

 

Another question is that of pickup.  I think the Keyser mech is the old fashioned common return 'live chassis block' type, with pickups only on one side and one wire feed to the motor returning through the chassis, with only the feed side wheels insulated.  So I won't be able to substitute the K's wheels in the Bachmann chassis, which in any case would be set very low, possibly fouling on stuff in the 4 foot and leading to problems with the vertical play of the pony and radial trucks.  It would also mean that the buffers would sit too low even with tbe beam inverted.  I am pinning a good bit of hope on the Keyser chassis running, or at least being capable of being made to run, as it will be a more suitable basis for the model, obviously.

 

If I have to use the Bachmann chassis, currently in a non-running condition and with it's own problems, it will have to be with the K's wheels and we've already seen the perils that that leads us to.  The wheels would have to be replaced and finding replacements with the correct number of spokes to represent this very distinctive prototype might be an issue, and the bodyshell would have to be raised with packing to ride at the correct height.  Clearance below the Bachmann cylidners might be problematic as well; everything drops by 1mm, scale 3 inches, the correct half of the reduction of 6 inches in wheel diameter. 

 

Much of this is 'wait and see' until the model arrives, allegedly on Friday.  If I have to use the Baccy chassis block, a significant amount of surgery to get it to sit at the correct height with axles 1mm lower which might have to run in tubes will be needed. 

 

The 'reversed' chassis will not be a problem if I can use the K's chassis, which is of course the right way around, otherwise you are right, I'll either have to reverse the Bachmann chassis, which could lead to problems hiding the motor (but enable cab detail), or live with it as it is, but the wheel spacing of a 44xx is quite distinctive and this might be more than I can tolerate.

[Craigw]

"meaning that the boiler and firebox protruded more from the top of the tanks and made the loco look even more 'gawky' and top heavy than the more familiar 45xx; the whole effect is out of proportion and awkward. "

 

Speak for yourself Johnster!!

 

To me, the 44XX is absolutely spot on and the 45XX looks like it has been jacked up and does not sit right.

 

The 44xx is perfection

 

Two Mitchell 44xx kits are in my stash

 

Regards,

 

Craig w

[Hal Nail]

11 hours ago, The Johnster said:

the running plate was a little lower, which in turn meant that the tanks which rested on top of it were corresepondingly a little lower, meaning that the boiler and firebox protruded more from the top of the tanks and made the loco look even more 'gawky' and top heavy than the more familiar 45xx

 

7 hours ago, The Johnster said:

They're sort of so ugly they come out the other side and are beautifully ugly!

 

Ive heard this about Mick Jagger from various women folk!

 

I'd never noticed the body differences before (pretty sure Malcolm Mitchell didn't either!) - but now I've looked the firebox in particular does stand higher above the tanks. I'm not convinced the boiler is pitched higher above the running plate tho; I think it is just that the tanks themselves are slightly shorter - the proportion of tank height to cab looks different to me. The boiler handrails hit the tanks slightly nearer the top (though they would either way) but if you only look at the boiler, stays and buffer beam area, they look the same in both to me.

 

I may of course be wrong on all that but no question the 45xx is better looking - very much Keith Richards :)

Edited May 3, 2022 by Hal Nail

[KeithHC]

I was a bit confused with the allocation for 4557. You noted transferred to Narbeth but there was no shed there. So I thought  it maybe Whitland that had several 45’s. No I found on the BR database it went to Neyland.

 

Keith

[Miss Prism]

Boiler pitch on 44xx was 7'6", and on the 45xx it was 7'9".

[Hal Nail]

9 minutes ago, Miss Prism said:

Boiler pitch on 44xx was 7'6", and on the 45xx it was 7'9".

So lower in fact?

[Miss Prism]

Just now, Hal Nail said:

So lower in fact?

 

Yes. Cab and chimney were approx 4" and 3" lower respectively.

[Hal Nail]

9 minutes ago, Miss Prism said:

 

Yes. Cab and chimney were approx 4" and 3" lower respectively.

So even identical GWR locos were completely different!

[The Johnster]

1 hour ago, KeithHC said:

I was a bit confused with the allocation for 4557. You noted transferred to Narbeth but there was no shed there. So I thought  it maybe Whitland that had several 45’s. No I found on the BR database it went to Neyland.

 

Keith

 

My only excuse is that both end in 'land'.  These 'senior moments' are beginning to coelesce into whole days now.  Yes, it went to Neyland, and I've seen a photo of it there in lined black unicycling lion as modelled by Bachmann.  This is a livery I would like to include on Cwmdimbath but I cannot find any photographic evidence of any Tondu loco ever carrying it, so have cheated and incorporated a Rule 1 Barry 3MT, 82001.  This is also a 'loco included because I like it' beast, it'll be an LMS Garratt next with a rake of Pullmans.

[The Johnster]

6 hours ago, Craigw said:

 

To me, the 44XX is absolutely spot on and the 45XX looks like it has been jacked up and does not sit right

 

1 hour ago, Hal Nail said:

 

I may of course be wrong on all that but no question the 45xx is better looking - very much Keith Richards :)

 

I think that part of the charm of the 44xx is it's sheer oddness, the driving wheels are ridiculously out of proportion, and the sight of them whizzing around and the loco making all that fuss with 2-coach trains at 20mph must have raised a bit of a smile, like daschunds with greyhound delusions.  Personally, I'm not sure that 45xx are particularly good looking engines, but a 44xx looks as if it's borrowed roller skate wheels!  Mick Jagger on castors...

 

The 3 small prairie classes are all ugly ducklings, but the ugliest to my mind is the 4575.  But I am in no position to be judgemental or take any moral high ground on the subject of ugliness; I'm not exactly Brad Pitt myself!

[KeithHC]

26 minutes ago, The Johnster said:

 

My only excuse is that both end in 'land'.  These 'senior moments' are beginning to coelesce into whole days now.  Yes, it went to Neyland, and I've seen a photo of it there in lined black unicycling lion as modelled by Bachmann.  This is a livery I would like to include on Cwmdimbath but I cannot find any photographic evidence of any Tondu loco ever carrying it, so have cheated and incorporated a Rule 1 Barry 3MT, 82001.  This is also a 'loco included because I like it' beast, it'll be an LMS Garratt next with a rake of Pullmans.

Thanks and I agree with the rule one. In my future planed layouts I have always had an interest in Cardigan Town. Again using rule 1 along with 16xx and 45/4575xx I would also include a dean goods. There is no record of one on the branch other than a sighting of one at Cardigan junction.

 

Keith

[The Johnster]

1 hour ago, Miss Prism said:

 

Yes. Cab and chimney were approx 4" and 3" lower respectively.

 

That's the end of my plan to use the Bachmann cab.  3" is of course the difference in driving wheel radius, half the diameter, and the height abover rail level of the centre line of the axles on which the engine sits.

 

52 minutes ago, Hal Nail said:

So even identical GWR locos were completely different!

 

Yes, except for when they were the same. 

 

GW locos, especially Churchward-based designs, everything with outside cylinders since 1906, all looked the same because they were made up of a range of standard parts sitting on different sized driving wheels, which is what made them differently identical and identically different at the same time.  Churchward orininally used standard sizes of driving wheels at 4'1", 4'7", 5'8", and 6'8", under no more than 6 sizes of boilers, and with a very small variety of axle spacings so that he could use common parts for motion.  Cylinder and piston sizes were pretty standardised as well.

 

The result was that the pitch of the boiler centre line and the relationship of the boiler to the running plate were the main ways of differentiating between otherwise very similary locos.  Collett continued in much the same vein, but introduced new driving wheel sizes to add to the fun as well as new boilers to cope with bigger engines and the variety of South Wales tank engines rebuilt after the grouping, which found their way into new Swindon designs like the 2251.

 

So, differntly identical, and identically different.  I was brought up around them and find this easy to deal with, but I completely understand why some people have trouble with it.  Modelling GW engines, especially Churchwardian ones, is about capturing often quite subtle differences in proportion and character, and one is always learning; yesterday, if asked, I'd have told you that the boiler centre line was pitched the same on a 44xx as on a 45xx, and it looks as if it is in relation to the running plate level; it is 3" lower on a 44xx because the running plate is 3" lower on a 44xx, because the wheels are 6" smaller in diameter and the frames sit corresepondingly 3" lower; same goes for the chimney. 

 

But the cab is 4" lower, though I'm at a loss to explain the extra inch.  This I suspect means that the arc of the cab roof is higher and more pronounced.  The cab roof is one of the most important contributors to the general appearance of GW tank engines, and it is important to get it as right as you can.

 

I will be making some assumptions with this model, primarily that Keyser have got the proportions and sizes of everything right above the running plate.  Having studied the photos of the model I have bought, I am happy with the bodyshell and doubt if I will be doing much to it.  Whoever built it made a reasonable job and the cast whitemetal rivet detail is not bad, but I will be relying on Mr Keyser to have got the shape right.  I was thinking yesterday that I might incorporate the Bachmann cab and bunker assembly for better detail, but this has now been ruled out by authority of the Peaky ****ing Bloinders, I mean, by authority of Ms Prism.  Bachmann will be providing the motion and possibly the slide bars and motion brackets, not to mention the vacuum pump, and as much underframe detail as I can get away with, and possibly the pickups as well.  These are the weak points of the K's kit IMHO.

 

I'm in trouble if I can't get the K's chassis to run properly and have to resort to modifying the Bachmann 45xx, which will lead to all sorts of mischief and the project will degenerate into ballpark accuracy modelling fairly quickly.  The K's model seems not to have any pickups fitted at the moment and only one wire is visible; investigation needed. 

[Miss Prism]

7 minutes ago, The Johnster said:

I will be making some assumptions with this model, primarily that Keyser have got the proportions and sizes of everything right above the running plate.

 

Pendon used to run a K's 44xx, and Guy Williams rated it highly for accuracy.

 

[The Johnster]

Good enough for Guy Williams is plenty good enough for me, Ms P!  I guess he'd worked it up a bit below the footplate, though!

[Miss Prism]

That was before the Mitchell kit of course, which changed the landscape!

[Hal Nail]

1 hour ago, The Johnster said:

yesterday, if asked, I'd have told you that the boiler centre line was pitched the same on a 44xx as on a 45xx, and it looks as if it is in relation to the running plate level; it is 3" lower on a 44xx because the running plate is 3" lower on a 44xx, because the wheels are 6" smaller in diameter and the frames sit corresepondingly 3" lower; same goes for the chimney. 

 

But the cab is 4" lower, though I'm at a loss to explain the extra inch.  This I suspect means that the arc of the cab roof is higher and more pronounced.  The cab roof is one of the most important contributors to the general appearance of GW tank engines, and it is important to get it as right as you can.

 

So if on a 44xx the running plate is lower and the boiler is correspondingly lower, yet more of the firebox shows above the tanks (as you pointed out initially), that suggests the tank tops are not as high above the running plate as on the 45xx - which was my thought from looking at photos and judging proportions. 

 

I've noted elsewhere that apparently similar coaches actually have all sorts of little dimensional differences and frankly this isn't really surprising! As you say, its certain key components, be it castings or more complex subcomponents like a boiler, that made sense to reuse and save effort.

 

[JimC]

1 hour ago, The Johnster said:

yesterday, if asked, I'd have told you that the boiler centre line was pitched the same on a 44xx as on a 45xx, and it looks as if it is in relation to the running plate level; it is 3" lower on a 44xx because the running plate is 3" lower on a 44xx, because the wheels are 6" smaller in diameter and the frames sit corresepondingly 3" lower; same goes for the chimney. 

They're even more different than that. If you look at the weight diagrams the entire relationship between chassis and superstructure is subtly different: look at the cylinder positions relative to the wheels and the overhangs front and rear. There must have been a considerable redesign done: it was anything but a straight rewheeling.
The relationship between the front of the water tank and the leading driving wheel is worth noting too.

Edited May 3, 2022 by JimC

[Denbridge]

44 minutes ago, Miss Prism said:

That was before the Mitchell kit of course, which changed the landscape!

Pendons 44xx was scratchbuilt by Paul Morgan in the early 1980's. It is a beautiful model that I've always looked out for when visiting.

[Craigw]

With all this talk of the 44XX, it is time for a photo. This is a scan of a negative I won via Ebay. Please do not post it anywhere else with out my permission. With the lack of the cab sliding shutters, portholes above firebox and the taller vacuum pipe I am suspecting early 1920s. I am not sure of the location so suggestions welcome. 

 

As one who is used to the proportions of locos with smaller wheels, I find that the 44 looks more balanced to me.

 

Must be an Australian thing!

 

Regards,

 

Craig W

[The Johnster]

50 minutes ago, JimC said:

The relationship between the front of the water tank and the leading driving wheel is worth noting too.

 

Presumably the result of 'reversing' the axle spacing for the 45xx.  The tank looks to be in the same place on both locos in fore and aft terms, with the top of the motion bracket bolted to the front of it, but the leading wheel axle centre positon is moved backwards a smidge on the 45xx cf. the 44xx.