Current and Proposed New-Builds

"Beachy Head" had an emotional pull with many Bluebell members, especially some of the older members, since the original had only just missed preservation, and it had been used both in regular traffic and on rail tours over the line. So to many members, it always felt like a missed opportunity to preserve the original.

It was for that reason that the project was to "recreate 'Beachy Head'", rather than (say) "build the next loco of the H2 class".

Thus it was serendipitous that a suitable boiler became available, essentially that became the catalyst to start a project that was already an idea in people's minds. I suspect that had the boiler not been available, the project wouldn't have started but I also doubt any other loco would have been chosen instead. In other words, the desire at the time was explicitly to recreate Beachy Head, not just "choose a suitable loco to build". Obviously, as Beachy Head approached conclusion, there was discussion of both a Craven 2-4-0 and the Wainwright E class, but by that stage, the concept of new build steam was much more firmly embedded: going back to the mid 1990s, it was a bold leap of faith.

There have been two other new builds at the Bluebell that I have heard people talk about, but I don't think in any more detail than mess room conversation. One was a suggestion that 1638 - the Maunsell U class - should be restored as a three cylinder U1, I think really for "completeness" sake. (There are 4 U boats preserved, but no U1s). There has also been sporadic talk about back-converting one to a K class 2-6-4T, which would be a much more suitable loco for the line, but again I don't think anything much more serious than "you could do that ..."

The other was to build a new Maunsell / Wainwright S class 0-6-0ST. The original - of which only one was made - was a saddle tank conversion of a Wainwright C class goods, built when there was a need for a heavy shunter but no capital available to construct an entirely new loco as Maunsell wanted; instead they took a C class and converted it. I know at least one person who was of the view that given we had a C class to copy, and how fundamentally simple the design is, a new build S would be eminently doable. But again, I don't think it went any further than an interesting topic of conversation.

Tom

 

It's an idea put forward by many without really considering the consequences. By doing this you would lose an awful lot of heating surface. A simple example can be found in the LNER J27's. They were originally supplied with a simple saturated boiler having 254 2" dia tubes giving a heating surface of 1463 sq. feet. Subsequently a superheated boiler was designed and fitted to some of the locos. Ignoring the heating surface provided by the superheater elements, there were 102 2" dia tubes giving 583 sq feet and 24 5¼" dia tubes giving 360 sq feet so that's a total of 943 sq feet. My guessing stick makes that a reduction in heating surface of about 36%. That's a huge reduction by any standard. In addition to the reduction in heating surface area there is also the free gas area to be considered. To stop all the gas from going through the flues they would need significant blanking and that would reduce the FGA significantly which would impact on the ability to burn the black stuff, not to mention the fact you'd end up with laminar gas flow through the flues which would reduce the heat transfer through them and a higher gas exit temperature.
If you simply wanted a loco to potter around without doing any real work hauling trains then it could be done but that's not usually required of a steam loco on most heritage railways where they are required to pull trains and maintain steam pressure.

Edited to mention laminar gas flow, as well.

 

Very interesting Tom, thanks.
Wasn’t there also a plan for a new build or conversion using 830?

 

Not I don’t think at the Bluebell. There’s an idea that pops up from time to time about using an S15 as the basis for a new build Urie H16 4-6-2T, but it falls over whenever you compare the leading dimensions and realise they have almost nothing in common. Doesn’t stop the idea resurfacing from time to time though.

(In Bluebell terms, 830 was then sold to pay for 928).

Tom

 

Re: GWS mainline running (or not) was covered in the Night Owl thread
https://www.national-preservation.c...ht-owl-4709-begins.34874/page-10#post-2683478

 

Just needs a hole for the key to wind it up.

 

The basis for Triangs R153 0-6-0ST, using the Jinty chassis, and numbered 748! Ive got one!!

 

I feel like I’ve read in an old Bluebell News about a half plan to use 830 as the basis for a new King Arthur… But even if that was the case, I don’t think it was ever more than just an idea!

 

Further to @Cartman and other queries re: D5910, aka the "Baby Deltic", here's a FAQ.

https://www.babydeltic.co.uk/faqs

Most notably, regarding main line running:

 

I have the Class 11(?) diesel shunter, minus its key... which I suspect uses the same chassis. One thing's for sure - my Hornby Type H key won't fit.

 

It was nessecary to cast an expensive new superheater header .
What kind of steam did it make in its stationary role?
And for what purpose?

 

Problem with that is that the Maunsell S15s were not the same as the Urie locos. If a spare Urie S15 (or 496 class as they were originally known) was available then the cylinders, motion, bogie and driving wheelsets were common. I have a copy of the memo from 'Jock' Finlayson to RW Urie listing all the drawings printed for RWU for his retirement which makes this plain. The problem with a Maunsell engine is that probably only the wheelsets (and axleboxes, &c.) are reusable. Even the driving axle springing was altered from coil to leaf spring. Shame really, it was a pipe dream of the ULS late Chairman to build a H16.
OT, again!
Pat

 

I hadn't really thought about it until mention of Beachy Head's superheater came up on here, but presumably having gone to the expense of having the header made for that loco, another could be cast from the same pattern for GNR 251? (Not suggesting for a moment this will happen... but it's nice to know the option might exist!)

 

I don't know for certain. Beachy Head has a 32 row superheater (8 * 4) but whether 251 does, I don't know. The relative proportions of tubes and flues was the sort of thing that developed over times without making any real external visible difference (generally the trend was towards more superheater area and less tube area as time went on).

The boiler in Beachy Head is a very late build (1941) LNER boiler, so it is possible that if 251 has an earlier boiler, it may also have fewer elements and therefore even hypothetically, the existing patterns may not be right. Someone who knows that loco better (or who can take a sneak peak in the smokebox ...) would have to comment.

https://www.bluebell-railway.co.uk/...pics23/new_steam_pipes_fredb3270_12jan23w.jpg

https://commons.wikimedia.org/wiki/File:32424_"Beachy_Head"_boiler.jpg

Tom

 

According to RCTS, GNR 251 acquired a 32-element boiler in 1932. The whole class of Ivatt Large Atlantics had 32-element superheaters by 1934.

@Hermod raises an interesting question about whether the superheater could have been omitted from the new-build "Beachy Head". In principle, it could have been built with a non-superheated H1 type boiler, but that would have meant new tube-plates, an expensive item. I don't know whether the project team ever had any hope of main-line operation for the replica, but if that was the case, you would not wish to go for an option of reduced power and efficiency. And then there would likely have been a wish to keep as closely as possible to the original design.

 

Deleted

 

As you say, an attempt to back-convert the boiler to unsuperheated form would have required new tube plates, which would wipe out any financial gain from not casting a new superheater header.

There was never any desire to go mainline. The loco was built by the Bluebell for the Bluebell, as such for most members, the ultimate desire is to see the loco in use on our line. Leaving aside any question of the cost, a mainline loco would likely spend considerable time away, reducing the opportunities for those of us who funded it to experience what we had funded. Of course, I'm sure you'd find someone somewhere who wished to see it go mainline, but it was never a project objective and not as far as I can see a desire from a significant number of members.

Tom

 

The big tubes can be exchanged for Serve-(Chapelon and all his miserly deeds) finned-tubes if some steel mill today know how to roll them.

 

Those are good questions. Anyone able to answer?

 

It was one of 4 boilers (another Atlantic boiler since scrapped?, an LSWR T1 boiler and a M.R./M&GN one) at Boulton & Paul Ltd.
More of the story here https://www.bluebell-railway.co.uk/bluebell/locos/atlantic/background.html
Ray.