R30134 Turbomotive boiler diameter.

[atom3624]

Hi there.

I realise the turbine-encasing valance could have a visual effect on the apparent size of the boiler, but did Turbomotive 6202 have a different boiler to the other Princess Royals?

Wiki simply says 'LMS #1 boiler' for both.

I've a blinkerless Hornby Coronation I've renamed/renumbered 6233 DoS for 'model reference'.

DoS 6233 - front of boiler diameter, just in front of the handrails, by smokebox door, trying to avoid rivets - 24.9mm

Turbo 6202 - same - 24.8mm.

SD previous model Lizzie 6201 - 24.2mm.

The boiler visually looks bigger as well - not just paint lustre, etc.

I have F.J. Roche 'Historic Locomotive Drawings' which does indicate the Coronation's outer casing diameter at the smokebox door being 6'2", which would be 24.7mm at 4mm / ft - not far out.

Unfortunately I cannot find reference to the Princess Royals, but am fairly certain it's slightly smaller.

Thoughts?

Al.

[What About The Bee]

I searched and searched, but never found a boiler diameter for Turbomotive. I could identify the boiler as "LMS Type 1".

The 1935 Railway Magazine dimensioned drawing may explain why there is no "diameter". It appears to be conical, not cylindrical. Perhaps you can scale the boiler diameter at various points

Bee

[What About The Bee]

I grabbed the Hornby Turbomotive side elevation image and on it, superimposed the Railway Magazine's illustration.

Atom, it is nearly a perfect match!

[atom3624]

Thanks for the background research.

I was simply looking at the 2 models side by side - early 2000's Lizzie super detail (loco drive with lamp brackets) and the 6202.

Visually there'll obviously be an effect of different materials, paint finishes, and the long cowling alongside the boiler, but the 6202 just LOOKED heftier.

I then measured where able, which is only the smokebox door end and got the 24.7-24.8mm - whereas that for Lizzie was 24.3mm. I tried as hard as possible to avoid the rivets, but there are the handrails and the tapered boiler to consider for other areas.

The reference point I had was a drawing for Coronations stating 6'2" (24.7mm) over-casing diameter at the smokebox door end. I got my blinkerless, renamed 6233 DoS (formerly Duchess of Abercorn (~R3100 +/-) I think) which looked identical in diameter to 6202, and measured 24.8mm - close enough to both 6202 and the correct 24.7mm).

All references indicate 6202 had the same boiler as other Royals (there were variations) but the difference is visible - Lizzie looking sleeker, more elegant - slimmer - and 6202 the same as the Coronation, a good 0.5mm larger.

Sounds miniscule I know, but it's visible, which heightened my curiosity.

Al.

[Fazy]

The older princess Royal models are under size all over the place. Including the boiler diameter. Try with the newer model

[Kim-344602]

The Stanier boilers came in 3 series which were all taper. The 1 series were for the pacifics but there are big differences between the Princess series and the Coronations. For a start those on the Coronations were shorter. The boiler made for 6202 was never fitted and became the spare for the first 2. 6202 was fitted with the one originally intended for 6203. When within a very short space of time, 6202's boiler was changed, the original went into the pool of spares for the second series but had the difference that it had 32 superheater elements. The replacement was not only domed but it had a 40 superheater. None of the other Lizzie's had 40 elements. The boiler for 6200 and 6201 were always slightly different and were not interchangeable with the rest of the class. So although all the pacifics were fitted with No 1 boilers, there were quite marked differences between locos. It was further complicated as the original boilers were not good steamers and some of the later series had combustion chambers.

As a matter of interest, the 2 series were intially to British Legion and the a slightly shorter modified version fitted to the 7P rebuilds.

The 3 series were fitted to the Jubilee's, Black 5's and 8F but again with variationd and not just with or without domes. Initially they had a vertical throatplate and long boiler. This was soon changed to a slightly shorter boiler with a sloping throatplate. Even within a single class, the 2 types were not interchangeable as the frames were different. Some of the early vertical throat plate engines had their frames changed and were fitted with the sloping ones. Their old boilers then went to form a pool of spares for the earlier engines.

[atom3624]

That's great information, more-or-less as I remember having read many years ago, but ...

Any idea what the diameter over casing the boiler is at the smokebox door end? I'm fairly certain my Lizzie is probably correct, just on/over 6', whereas the Coronation is sitting on 6'6-7" (a touch more than the 6'2" I found!)

Thing is the 6202 model's is the same as the DoS 6233 - that was my point.

Not critical I know, and it's probably an effect of the pristine paint and the turbine cowling bulking it out.

It runs well, which is the main thing. Mine has stayed on the track without issue - so far!

Al.

[Kim-344602]

I searched and searched, but never found a boiler diameter for Turbomotive. I could identify the boiler as "LMS Type 1".

The 1935 Railway Magazine dimensioned drawing may explain why there is no "diameter". It appears to be conical, not cylindrical. Perhaps you can scale the boiler diameter at various points

Bee

 

 

The boilers were tapered and not conical. ;)

The lower edge of the boiler was level. A true conical shape would be tapered all round. Easiest way to explain it is to make a cone slightly longer than you need, Now lay it on it's side. This will mean the front and back are not vertical so slice a bit off and you have the rough shape of a tapered boiler. It's why although it is not too hard to cast a tapered boiler in model form, it is very hard to roll from sheet metal and why the early kits like Jamieson had pre-rolled boilers.

Also what to see in the drawing is not actually the shape of the boiler itself but the cladding. On many locos especially on the GWR, the boiler is in 2 halves the rear part being quite strongly tapered and the front part either less so or even parallel. (Much like some of the early US locos.) Quite often the cladding hides this.

[Kim-344602]

That's great information, more-or-less as I remember having read many years ago, but ...

Any idea what the diameter over casing the boiler is at the smokebox door end? I'm fairly certain my Lizzie is probably correct, just on/over 6', whereas the Coronation is sitting on 6'6-7" (a touch more than the 6'2" I found!)

Thing is the 6202 model's is the same as the DoS 6233 - that was my point.

Not critical I know, and it's probably an effect of the pristine paint and the turbine cowling bulking it out.

It runs well, which is the main thing. Mine has stayed on the track without issue - so far!

Al.

 

 

From the drawing's I have which are of the domed boilers with combustion chamber, it is quoted as 5' 8 5/8" at the front increasing to 6' 3" at the rear. However that is the boiler size. There is the cladding on top of that. So around 6' for the smokebox would be about right.

The Roche drawing of the Duchess gives about 6' 1" across the cladding next to the smokebox although the Roche drawings are not always accurate.

I am wary of scanning the drawing and posting them in case of copyright rules. ;)

 

 

[What About The Bee]

Hello Kim

It is extremely unlikely that anyone would pursue a copyright infringement claim against a non-commercial post by enthusiasts.

Further, while it may have eluded me, I can find no specific rules about using copyrighted images in a post.

Hornby has let us know that their images are copyrighted.

Bee

[LTSR_NSE]

@bee - Ts&Cs are referenced in the rules regarding User Generated Content (which includes forum posts). The relevant Ts&Cs Quote reads:

“UGC submitted to Hornby Hobbies Limited is assumed to be your own original content unless specifically stated otherwise. If you have used the work of others you must have obtained the necessary rights or permissions to use it. If your content clearly identifies anyone else you acknowledge they have consented to the content being used by yourself as well as Hornby Hobbies Limited.

We shall not be liable for any claims arising out of the use of third party work.”

So basically if you post copyrighted images without permission from copyright owner, they could potentially sue you, but are more likely to simply issue a takedown request/notice to Hornby.

[What About The Bee]

Hi LT&SR_NSE

Welp, that explains why I couldn't find it. Not once did the word copyright, or copyrighted appear in the text.

Thank you for drawing that to my attention.

Bee

[atom3624]

Interesting discussion and thank you to contributors.

It would appear that 6202 really is 'there or there abouts' including boiler cladding.

Perhaps the nearly 20-yo engineered Princess is slightly under - outer diameter of Lizzie is 24.3mm / 6'1" equivalent.

Perhaps 6233 DoS should be larger?

Start of the thread was simply the observation that the 6202 model diameter was larger than Lizzie, nearly the same as DoS, but it appears 6202 is correct.

They're merest fractions at 1:76.2, but it can be seen!

Al.

[atom3624]

Fantastic video thanks for Flying Scots Dan, just posted on YT:

Al.