7027 Thornbury Castle

I used to love the Stephenson & Walschaerts Valvegear models in the cabinets, with their winding handles. Even as kid I understood that these were how real locomotives worked. I suppose the only twiddly handles nowadays will turn the mouth of Thomas the Tank Engine from a smile to a frown and back... I do hope the valvegear models are still there. By the way, looking back, it's a pity there weren't scale models of the different RC valvegears with cutaway sections in the camboxes and gearboxes...

Richard.

 

Fair point, and maybe I’m being a little hypocritical, but then how would you describe 37 901-906?
Are they ‘frankendiesels’?

 

What on earth does that make Class 13?

 

I think it makes sense to separate working life from preservation life. The 37/9s or the Dukedog are different from the Baby Deltic or the Hawksworth County because they were lashed up to serve operational need, rather than historical curios.

Simon

 

They seem more like 12 inch to the foot models, imitations of the real thing rather than recreations, to me.

I’m sure they’ll be great, but they’re different to eg Tornado or 82045.

Simon

 

The Baby Deltic project does not deserve the criticism it is getting. That thing is one of the most carefully planned out and comprehensive rebuilds of a diesel locomotive I have seen, together with the use of an original, working power unit.



Image is copyright to the Baby Deltic Project - taken from here: https://www.babydeltic.co.uk/progress-video

I don't know of the full details of the Ivatt group's work, but the Baby Deltic is a masterclass in metalwork quite frankly. Go and have a look on the website and see for yourself. When complete, it's going to be as close to an original member of the class you can get, even sounding like one.

Credit where it is due.

 

Maybe that was ''tongue in cheek '' ? Otherwise l disagree, the one gives historical precedence for the other.

 

Quite agree, and I don't believe I for one have voiced any criticism, but the fact remains that it is based around a cut and shut "preserved" class 37 (which for all I know may have been a preservation target for a group that wanted to restore it to original condition) that could have been restored as such, with the remains other other locos added. No-one seems to mind too much because there are quite a few others left of those classes and it is recreating something that otherwise no longer exists. I just don't really see why this one is OK but 4709 is generating so much pontification. Maybe it is just a steam v diesel thing.

 

I think it's trite to see the Baby Deltic as a simple "cut and shut" class 37 tbh! You treat each case on its own merit. Steam and diesel new builds/conversions cannot readily be compared, but I would say the Baby Deltic and the Saint conversions are roughly similar in terms of what was achieved. Both however use the correct power unit/boiler without compromising on the design.

 

There's a lot more class 37s in existence than there are Castles

 

I didn’t read comments about the baby Deltic as criticism. It’s clearly an amazing piece of work, and as a class I never saw in the flesh, I hope I get to see it running.

My points were simply…

a) that there’s a clear difference between parts of the national fleet being adapted and improved for operational reasons, versus enthusiasts assembling a high quality facsimile of an extinct loco for fun (which isn’t to demean what they’re doing, but to emphasise that it’s a hobby, not a business).

b) the comparison between reusing a 37 (50 still on operators books in use or in store, 20ish owned in preservation) or a 58 (25+ in store in various locations, 6 owned in preservation) as donors, where supply likely vastly exceeds demand and the donor would almost certainly have otherwise been scrapped, and a Castle that was actively being restored, seems… divorced from reality…

Simon

 

37372 wasn't preserved, it was brought from a scrapyard with the sole intention of making a Baby Deltic. One nose was completely smashed up, so not an ideal preservation candidate anyway - but perfect if you need a body shell to hack about!

The group has also had a clear aim and vision about what they want to achieve. The 4709 group seem to chop and change with what they're planning to do depending on what parts they can get their hands on. It started off as little more than a big wheeled 28xx! Now they're planning on using a Castle boiler because it's vaguely the right size, rather than saying "we're going to do it properly and build a new boiler".

@S.A.C. Martin's analogy is the best way of putting it, regarding the Saint and the Baby Deltic being similar in construction terms - frames from a donor loco with correct power plant fitted on top. 4709 seems a bit of a penny pinching bodge in comparison.

 

The only thing that a 47xx has in common with a 28xx is the wheel arrangement. You should think of a 47xx as a Grange with an extra pair of drivers and a bigger boiler!

 

As the 47xx came first; is not a Grange a 47xx minus a pair of drivers and with a smaller boiler ?

Michael Rowe

 

The real point is that all the locos mentioned represent different points on a spectrum and really I don't think any of us who aren't actually involved in any of these projects have the right to suggest or tell their active supporters that what they are doing is right or wrong. Is it more important to keep the identity based on the frames, wheels, boiler or cylinder? At what point is a line crossed and what are the apposite merits to consider?

 

By all accounts, Flying Scotsman as it exists today includes few or no original parts, and certainly some major parts are not even direct replacements for those fitted originally but to different designs. Identity seems to be in the mind of the beholder, or possibly the accountant. Considering the amount of mix-and-match that has always gone on, I'm fairly relaxed about current projects that work on that basis, and I have supported some of them (including 10000, which is intended as a re-production which will look and sound like the original, with the same model of power unit and almost identical bogies but considerable differences in some other components). For Thornbury I'm prepared to wait and see what eventuates. I have been given to understand that even if they build a brand new boiler for 4709 it will need to be a bit slimmer than a No.7 to fit safely under the wires at Didcot on its way in or out, so in the end about the same size as a No.8.

 

You appear to have forgotten something. The cylinder castings have been made to suit the diameter of the smokebox fitted to a No. 7 boiler. The only way they could lose height is to do a 6023 job.

 

I would have thought that a new "slimmer" boiler would count as a new design and, therefore, have to have all the mandatory design approvals that this entails - a very long winded and expensive process for no good reason. As Std Tank states above it would be much easier to fit a cut down chimney, safety valve and cab to the number 7 boiler.
Ray.

 

Cant be that onerous a process, nearly every newbuild boiler and most boiler repairs are not identical to the original specs due to the difference in available materials and all have to pass rigorous inspection and materials provenance checks regardless...

 

Don't shoot the messenger. I was passing on what I have been told. I take no responsibility for its accuracy either way.

If you look at the pictures of 4700s, there does indeed seem to be scope for reducing the height of the bits on top as with the King, but the 4709 people appear to believe otherwise.

It would be helpful if they were to come on here and/or in one of the magazines and set out exactly what all their possible options are, and the reasoning behind each of them, including why they believe they can't "do a 6023 job".

They do have their own email address, but as that was on the letter that came to only some of us I am not sure whether I should quote it here. However they also have a contact page: https://www.4709.org.uk/contact . Maybe ask specifically about the new cylinder castings being designed to take a No.7?