Rapido OO Gauge GWR 44xx/45xx/4575 Small Prairie

[didcot]

Looking good though. 

[gwrrob]

3 hours ago, rapidoandy said:

 

 

 

 

Any chance of shewing everyone the cab detail after you've recovered from Warley please @rapidoandyIt looks amazing.

[Siberian Snooper]

Hurrah, no cab shutters.

 

 

[Miss Prism]

9 hours ago, rapidoandy said:

 

Whoops!!

 

That's a 45xx coupled wheelbase (5'6" + 6').

 

A 44xx needs a 6' + 5'6" coupled wheelbase.

 

The wheels are wrong for a 44xx. The footplate is at the wrong height for a 44xx.

 

Nice parallel chimney for a pre-1925, but it would not have been seen on an outside-piped loco. (Nor with a rear lamp shield.)

 

Put the vacuum pump on the other (right hand) side.

 

I don't think any of these locos had double battery boxes (I welcome being corrected), but any battery box(es) would be on the other (right hand) side, and not on the lhs.

 

I can feel a gwr.org.uk page brewing.

 

 

 

 

Edited November 27, 2022 by Miss Prism
wheel and footplate comment added

[Corbs]

9 hours ago, Harlequin said:

Thanks Andy. Looking good but the 44xx and 45xx wheelbase should be 6ft between leading and centre driving wheels, and 5ft 6in between centre and trailing driving wheels. See the drawings Mikkel posted above.

 

That is the opposite spacing to the 4575 class...

 

14 minutes ago, Miss Prism said:

 

Whoops!!

 

That's a 45xx coupled wheelbase (5'6" + 6').

 

A 44xx needs a 6' + 5'6" coupled wheelbase.

 

 

Just want to check this as they conflict - I understood that the 4500 and 4575 both have the same size wheels (4ft 7.5in) and wheel spacing (5ft 6in + 6ft) and that it was the 4400 that differed by having both different wheel size (4ft 1.5in) and wheel spacing (6ft + 5ft 6in) - rather than the 4400/4500 sharing a wheelbase.

 

 

[Mikkel]

What you say is correct Corbs.

 

Both the drawings that I posted show 44xxs, but in different build conditions as I was contemplating whether a later version could be backdated to the original version (post now edited to avoid misunderstandings).

 

Edited November 28, 2022 by Mikkel

[Harlequin]

10 hours ago, Corbs said:

 

 

Just want to check this as they conflict - I understood that the 4500 and 4575 both have the same size wheels (4ft 7.5in) and wheel spacing (5ft 6in + 6ft) and that it was the 4400 that differed by having both different wheel size (4ft 1.5in) and wheel spacing (6ft + 5ft 6in) - rather than the 4400/4500 sharing a wheelbase.

 

 

I was led astray by a weight diagram supposedly of the 4500 published in “Great Western Moguls and Prairies” by Maidment.

But looking at it again I think it’s mis-attributed. I think it’s a drawing of a 4400 in later form.

 

Sorry for the momentary confusion.

 

Of course you’re right, Corbs, and there’s a photo of 4500 in the same book, in her year of construction, still numbered 2161, showing the 5ft6 leading + 6ft trailing spacing. Pretty conclusive!

Edited November 28, 2022 by Harlequin

[Cwmtwrch]

12 hours ago, Miss Prism said:

I don't think any of these locos had double battery boxes (I welcome being corrected), but any battery box(es) would be on the other (right hand) side, and not on the lhs.

You are correct on the location. I think, but am open to correction, that the double battery box is actually two single boxes on one frame - one is for ATC, which the 44XX may have got late in their lives, which I doubt though, as 45XX/4575 only seem to have acquired it from the mid-1950s onwards, judging from photographs, some with conduit on RHS but no visible box, which may therefore have been in the cab. The other is for communication bells on auto-fitted locos, and the only small prairies so fitted were some 4575 class from 1953 onwards, which got presumably got ATC on conversion. My reason for thinking two separate battery boxes were used is that the two systems were kept quite separate, probably for safety reasons, but, as I said, I am open to correction.

[The Fatadder]

Good to see the rivet detail on the footplate is there, one of the bigger weak points of the Bachmann model.  likewise the chimney looks a lot better (a more pronounced weakness of Bachmanns).  I am particularly interested to see how the con rods look when physical models start to appear, another area where I think there could be improvement.   I have 4 of the Bachmann tanks for Brent, two of each variant, most of which are now fully weathered and in service.  Will I be replacing them all, probably not, however I will certainly be getting a 44xx and selling the Bachmann body that I had been planning to modify.   I will also be looking to see what I can do to bring by Bachmann examples up to as close a matching standard as possible.    If the 44xx really blows me a way, who knows...

[No Decorum]

I’ve noticed a trend of more interest in the 44XX than in the 45XX and 4575, which matches my reaction. I recall a kerfuffle when the first Bachmann Small Prairie appeared. It was advertised as DCC ready but when the folks at Bachmann took the top off, it wasn’t. Subsequent models did have DCC sockets. I note, though, that Rapido’s will have speakers fitted and flickering fireboxes. I bet the 44XXs will outsell the later versions but I wonder how many will be tempted by son et lumière and extra detail to replace their Bachy models. Certainly, I think that the Counties and especially the Saints are more in need of updating than 45XXs and 4575s. Hornby’s Star isn’t stellar either.

[CoombeTown]

Rapido have really caught me off guard here. I recently bought a second 4575 to fulfill my need for an additional freight engine. However, it needs a stay-alive, which I was going to add with sound and a firebox flicker myself.

 

Space inside the Bachmann model is quite cramped so it would be a challenge to retrofit. If Rapido produce this at a reasonable cost I'd definitely be looking to replace one, if not both of my current examples.

 

My one plea is, please Rapido, include a stay-alive, even if it provides just a couple of seconds to get across a dodgy point blade, nothing drives me more insane than a brief break in sound before the auto frog changes!

[TrevorP1]

26 minutes ago, DRoe96 said:

Rapido have really caught me off guard here. I recently bought a second 4575 to fulfill my need for an additional freight engine. However, it needs a stay-alive, which I was going to add with sound and a firebox flicker myself.

 

Space inside the Bachmann model is quite cramped so it would be a challenge to retrofit. If Rapido produce this at a reasonable cost I'd definitely be looking to replace one, if not both of my current examples.

 

My one plea is, please Rapido, include a stay-alive, even if it provides just a couple of seconds to get across a dodgy point blade, nothing drives me more insane than a brief break in sound before the auto frog changes!

 

I'm in pretty much the same boat although I have no need of sound, steam effects, firebox glow, cursing fireman or whatever.  I have two Bachmann 4575s and neither gets much use, principally because they both have poor slow running and sound like a concrete mixer.

 

With Manors, E1s and sundry other goodies due next year there is no way I can justify a 4575 as well. However, my guess is these are 2024 releases and if perfect slow running were guaranteed I might be persuaded to have one and put mine on eBay...

 

I'm going to wait and see how things pan out but full marks to Rapido for their efforts. A much needed loco for most GW and BR(W) layouts.

 

 

[Miss Prism]

Cwmtwrch, you're right - my mistake for saying 'double battery boxes', I should have said 'twin battery boxes' (example on an 0-4-2T). And yes, the electrical circuits were kept separate I think.

 

 

Edited November 28, 2022 by Miss Prism
added example

[Dunsignalling]

3 hours ago, No Decorum said:

I’ve noticed a trend of more interest in the 44XX than in the 45XX and 4575, which matches my reaction. I recall a kerfuffle when the first Bachmann Small Prairie appeared. It was advertised as DCC ready but when the folks at Bachmann took the top off, it wasn’t. Subsequent models did have DCC sockets. I note, though, that Rapido’s will have speakers fitted and flickering fireboxes. I bet the 44XXs will outsell the later versions but I wonder how many will be tempted by son et lumière and extra detail to replace their Bachy models. Certainly, I think that the Counties and especially the Saints are more in need of updating than 45XXs and 4575s. Hornby’s Star isn’t stellar either.

I think the 44xx was bound to be the one to attract most attention given that the 45xx and 4575 classes have already been produced by Bachmann. 

 

I'll only be going for the earlier type for now, but when I've seen how that compares with my existing locos, might well spring for more. TBH, though, little of my WR stuff sees regular use these days and there's not much benefit to having a better 4575 if it stays in the cupboard!

 

Sound etc. is not an attraction for me.

 

Hornby's (Tri-ang-Hornby's?) old tender-drive Saint was a pretty rough approximation to put it mildly and referring to any new one as an update probably confers more respect than it deserved. I presume they haven't sneaked another (better) one out while I wasn't looking!

 

John

[No Decorum]

2 minutes ago, Dunsignalling said:

I think the 44xx was bound to be the one to attract most attention given that the 45xx and 4575 classes have already been produced by Bachmann. 

 

I'll only be going for the earlier type for now, but when I've seen how that compares with my existing locos, might well spring for more. TBH, though, little of my WR stuff sees regular use these days and there's not much benefit to having a better 4575 if it stays in the cupboard!

 

Sound etc. is not an attraction for me.

 

Hornby's (Tri-ang-Hornby's?) old tender-drive Saint was a pretty rough approximation to put it mildly and referring to any new one as an update probably confers more respect than it deserved. I presume they haven't sneaked another (better) one out while I wasn't looking!

 

John

Given the fuss Hornby made over Coronation, I would have thought a decent retool with a decent finish would have had no chance of sneaking out. SK would have shouted it from the rooftops!

[Dunsignalling]

11 minutes ago, No Decorum said:

Given the fuss Hornby made over Coronation, I would have thought a decent retool with a decent finish would have had no chance of sneaking out. SK would have shouted it from the rooftops!

 

Indeed, he'd probably have roped in the Band of The Royal Marines for the occasion. 🥸

[The Stationmaster]

On 27/11/2022 at 22:57, Corbs said:

 

 

Just want to check this as they conflict - I understood that the 4500 and 4575 both have the same size wheels (4ft 7.5in) and wheel spacing (5ft 6in + 6ft) and that it was the 4400 that differed by having both different wheel size (4ft 1.5in) and wheel spacing (6ft + 5ft 6in) - rather than the 4400/4500 sharing a wheelbase.

 

 

There is another difference between the 44XX and the 45XX/4575 and that is the overall wheelbase. which is 26 ft 6" for the 44XX and 26ft 10" for the 45s.  This difference comes from the spacing between the leading carrying axle and the leading driving wheel axle which is 8ft on the 44XX and 8ft 4" on the 45s.

 

This difference will presumably create a difference in respect of the distance between the axle centres and the vertical centre line of the blast pipe/Chimney.  On the 45s the leading carrying axle is 3ft 4" ahead of that centre line and the leading driving axle centre is  is 5ft behind that centreline.  Alas I can't find comparable dimensions for the 44XX but the GWS might well have the relevant drawing.  

 

In any case if you are looking at GWR engines it is sensible to consult the GWS drawings list as it is fairly completely catalogued and is available online plus their copies of drawings are considerably cheaper than drawings from the NRM.  But there are certain GWR drawings which should be treated with caution, particularly GA drawings which represent what should have been built rather than what the works actually built.  Dimension on weight diagrams should be trustworthy in view of the purpose they served and they - in my experience - test out against the engine they represent.

[melmoth]

One thing I'm not sure has been mentioned so far (apologies if I've missed it) is that the draft CAD of the 45xx has the original style of a 'straight' front end as per the first 30 (?) locos when built, as opposed to the 'Holcroft curve' on all later engines from new. I might not be alone in applauding this, as I'd rather not have to carve a Bachmann model to represent 4507 in the 1950s.

 

Oddly though, the 44xx draft CAD appears to have the curved front end, which none of them were built with.

[The Stationmaster]

As with various other GWR engines with two outside cylinders there is a critical need to understand the difference (and date of change) between 'as built' and 'as fitted with new cylinders and revised front end'.  And that includes knowing whether wherher or not the drop front end was, or wasn't, altered to the later, curved, pattern when the cylinders were renewed.

[Corbs]

13 minutes ago, melmoth said:

One thing I'm not sure has been mentioned so far (apologies if I've missed it) is that the draft CAD of the 45xx has the original style of a 'straight' front end as per the first 30 (?) locos when built, as opposed to the 'Holcroft curve' on all later engines from new. I might not be alone in applauding this, as I'd rather not have to carve a Bachmann model to represent 4507 in the 1950s.

 

Oddly though, the 44xx draft CAD appears to have the curved front end, which none of them were built with.

 

Almost but not quite - the 4500 CAD has the curved front end but with an angle underneath. Tooling/livery variants are not confirmed at this stage.

 

The angled front ends were slightly different as the join is up against the smokebox saddle and the valve chests poke out.

 

From my notes, only 4400, 4407 and 4410 were rebuilt with the Holcroft curve from the 4400 class.

 

 

[The Stationmaster]

45 minutes ago, Corbs said:

 

Almost but not quite - the 4500 CAD has the curved front end but with an angle underneath. Tooling/livery variants are not confirmed at this stage.

 

The angled front ends were slightly different as the join is up against the smokebox saddle and the valve chests poke out.

 

From my notes, only 4400, 4407 and 4410 were rebuilt with the Holcroft curve from the 4400 class.

 

 

One thing I do wonder is if a 44XX was re-cylindered and acquired the Holcroft curve in the frame drop did it affect the wheelbase between the leading carrying wheel axle centre and the leading driving wheel axle centre?

[Cwmtwrch]

3 hours ago, The Stationmaster said:

This difference will presumably create a difference in respect of the distance between the axle centres and the vertical centre line of the blast pipe/Chimney.  On the 45s the leading carrying axle is 3ft 4" ahead of that centre line and the leading driving axle centre is  is 5ft behind that centreline.  Alas I can't find comparable dimensions for the 44XX but the GWS might well have the relevant drawing.  

http://www.greatwestern.org.uk/drawings/loco/loco211.jpg

2 hours ago, The Stationmaster said:

One thing I do wonder is if a 44XX was re-cylindered and acquired the Holcroft curve in the frame drop did it affect the wheelbase between the leading carrying wheel axle centre and the leading driving wheel axle centre?

The new cylinders were a direct like-for-like replacement, so far as I know [everything still had to match up with the No. 5 boiler], so the only way to alter the wheelbase would be to alter the standard pony truck arrangements, which seems both unlikely and unnecessary, so I would think not. It would also in theory result in the need for a new weight diagram.

[The Johnster]

I have to say that I am delighted with Rap’s announcement of a 44xx, which is a brave move IMHO as there cannot be much obvious demand for them There are no preserved survivors or (TTMOMK) any plans to recreate one, which removes interest and possible market from that quarter, and they are relatively obscure engines of a small class and associated with only three locations, the Princetown (most famously), Porthcawl, and Much Wenlock branches; AFAIK they were not used elsewhere.  
 

That said, the LSWR Adams Radial and Beattie Well Tanks had a similar history for the bulk of their lives and that has not prevented their success as RTR models.  I suspect enthusiast awareness of these locos is higher than that for ‘another GW prairie’, though.  
 

44xx were intended as Churchward’s standard branch line engine, but to my mind the shortcoming is obvious and I cannot fathom why Churchward failed to predict it; the 4’1” driving wheels were more suited to mineral work and a bit more speed was needed for branch work than the 44xx could comfortably provide; little wheels mean more piston strokes for a given distance as well, which means more steam is chucked up the chimney and water and coal consumption rises.  Only 11 were built before the redesign that became the 45xx, the differences outlined above. 
 

The 44xx found a niche for themselves all the same, branches with a combination of low line speeds, sharp curvature, and steep gradients.  My interest with them is as locos allocated from new to withdrawal in 1953 (a result of the introduction of their big brothers the 4575 class for auto work) to Tondu for the Porthcawl branch, an upgraded tramway, where the line speed was 15mph and which had vicious tramway curvature.  For the worst stretch at North Cornelly they were the only locos allowed the breakneck pace of 15mph; all others, including the replacement 4575s and later 64xx, being restricted to 5mph. 
 

Two locos were allocated daily, one for passenger and one goods, and they were swapped during their lunchtime visit to the shed for servicing and crew change.  They were turned during this visit as well, to even out flange wear!

 

I intend to model 4404, with outside steam pipes and early BR ‘BRITISH RAILWAYS’ Egyptian Serif livery; not sure what liveries Rap will produce but it would be nice if they did this one!

[woodenhead]

@The Johnster People will buy them because:

a). Rapido are making them

b). Cute GWR branchline Tank

c). They already have a 45xx

d). Its compulsory to buy any new GWR tank engine - bigger engines are optional but tank engines are a must.  Even residents of the far north of scotland saw one type of GWR tank engine in their lifetime.

[Miss Prism]

I like the idea of tank engines being compulsory.