Stirling 8ft Single

[Jon Nazareth]

I've recently ordered wheels and cylinder castings to build a battery powered Stirling 8ft Single.  I've also sent cad files to a laser cutting company to get an idea of price for the main frames, bogie and tender frames.  The design was originally built by Peter Gardner of the 2 1/2" Gauge Association and apart from a very little tweeking with the back to back measurement, I don't think that there is any difference between 2.5 and G3.  Is there??

Regards
Jon

[Geoff Nicholls]

Jon,
gauge 3 v 2.5" scales has been a very touchy subject recently in the forum. They are quite close, sometimes the same, but not always. I suggest you browse through the postings. However the smaller the object, the smaller any difference might be. Are there no dimension on your CAD file?
I'm interested in your choice of loco, I have a GER Bromley 4-2-2 on my list (also with outside cylinders)

[Jon Nazareth]

All that I have are the files for the frames and that's it.  This probably sounds like a leap of faith and I'm thinking more and more that it actually is.  I'm relying on the fact that I will be able to pick up dimensions from the GA drawings that I have and what scant information that has been written about the project.  I've asked the 2 1/2 Gauge Association if there is any info on the machined dimensions of the cylinders and am waiting to hear.  If, I can place these, I'm hoping to be able to work 'backwards' from there.  A book that has been recommended is, The Stirling Singles by Leech and Body but it is quite scarce although there is a copy on Abe books going for £85.  I'm not leaping to buy it though.  Of course, there is always the local library which I will pay a visit to.  I like to sort things in my head once I latch onto a project and it's the cylinders that are worrying me at the moment.  More anon.

Jon

[Doddy]

There is always the NRM for drawings!

http://www.nrm.org.uk/researchandarchive/drawing?group=OPC&objid=12821-GNR-StirlingSingle-GA

[IanT]

Hi Jon,

There can be no difference in scale between any (standard gauge) locomotive built to 2.5" gauge - as the scale 'ratio' remains an immutable 1:22.6!  However it is true that 2.5" designs (whether for passenger hauling or scenic use) have deviated from scale for various reasons. LBSC was more concerned about function than form (including strict scale) for instance. There may also be constraints in terms of the available castings and existing track standards. However (in my personal view) if you are building from scratch, then there is really no reason to deviate from the correct scale (and original proportions) unless you really have to. Gauge '3' is pretty much unique in that it is already "finescale". Fortunately, we do not have (or need) the variations in gauge/scale that has so often plagued the smaller scales.

In terms of the 8ft Sterling there are two 2.5" designs that I am aware of. You have mentioned the Peter Gardner design but 8ft Sterling plans are also available from the Locomotive Design co. (Chris Barron). I have both of these plans and they do differ somewhat. A full set of castings are also available from the Association.

In terms of the original GA - these were published in 'The Engineer' (29th Sept 1871) and then reprinted in an "anniversary" book (in 1976 - celebrating 120 years of 'The Engineer'). I have this document too but the actual GA in it is about A3 in size. At one time the Association had an A4 sized copy of this drawing available for it's Members and they may still have some copies left (if requested). However, I'd be happy to scan it for you, although it may have come in several parts....

Reference has already been made of the 'Leech & Boddy' book (good details of locomotive variants and changes) but I would also mention L.T.C. Rolt's "Patrick Sterling's Locomotives" which has some very good detail photos of the 8 footers in it (and the GA too!). I have both should you have any particular questions.     

Anyway, very good luck with your build and please keep us informed of your progress.

Regards,

IanT

[Jon Nazareth]

I have bought from the Association a 'Design Pack' that has various drawings, articles and book extracts and I may be worrying unduly with regards to the machining of the cylinders.  Yes, I'll let you know how I get on but am not planning a start just yet.

Regards
Jon

[IanT]

Hi Jon,

I also have the full set of 'Sterling' castings, although (apart from gathering information) I have done no work on this engine as yet. When I do build, it will probably be as a gas-fired loco, as the grate is pretty small for coal firing. As you are building a battery electric version, I am not sure why you are quite so worried about the cylinder dimensions as they are purely cosmetic (unless you plan to steam her later?) but I'd be happy to suggest some usable dimensions if this was useful..

Although I've no plans to commence work on this engine anytime soon (e.g. some years!!), I might be persuaded to purchase a set of frames (for under the bench) if the price was reasonable. So would it help with laser cutting costs if we got two sets cut at the same time? I've not used external services like this before so have no experience in this area I'm afraid.

Regards,

IanT

[Geoff Nicholls]

For me the problem would be the clearance between the bogie wheels (with mudguards) and the cylinders or footplate

[IanT]

Ok, I understand Jon.

It does look pretty tight on the original GA and is probably going to be one of those cases where something will have to 'give' to achieve a workable model. Peter G doesn't give too many (any) details of the plate work but has joggled the frames at the front. I've not dug out my LDC drawings but suspect some form of clearance will also have been included in those.

A part built chassis for a Deeley Compound followed me home from the AGM and as we've been away from home (and workshop) quite a bit this year (and as I don't have any drawings for the engine) I've stripped it right back to its component parts, cleaned and de-rusted them and have been drawing them in TurboCAD whilst away. It seems well made, by someone who clearly knew what he was doing but the front bogie wheelbase is a scale 6" longer than the original (and with slightly smaller wheels) for this very reason I suspect....

By the way, I've noticed that Peter G (in his article) mentions that laser cut frames were available from the Association at that time (around 2005-6?) - so it may be worth enquiring if they have any left.. 

Regards,

IanT

[IanT]

Apologies Geoff - getting your messages mixed up with Jon's but hopefully my ramblings are still of use.....

Regards,

IanT

[John Baguley]

Ian,

Peter G had about a dozen sets of frames water jet cut by Sciss but they all went to interested parties a long time ago. Apparently Sciss have lost the original cutting files so I've drawn some new ones up and sent them to Jon. I've also done the tender frames and bogie, cutting drawings for which weren't available. I had to scale the tender frames from the small GA in the booklet so they may not be 100% accurate but probably close enough.

Peter never meant to write a construction article for the single but I think was 'coerced' to write something for the journal! He never produced any detailed drawings apart from the frames and the boiler. The booklet is just a collection of what information was available at the time.

The GA drawing of the full size loco that is available from the Association does print out at full size for 2½"/G3 but like most of these GA drawings it's packed with detail which is very hard to pick out!

John

[IanT]

Hi John,

Probably not a great surprise (although it's always worth asking!) but thank you for letting us know.

Regards,

IanT

[Jon Nazareth]

Ian

I've sent the files off to SCISS and am awaiting a reply, probably next week, and I'll let you know what the costs are when they come through.
I won't ever steam her but I'd like to get the cylinders right so that they line up with the connecting rods et al.  I'll only worry if I have to work it out myself 

Jon

[Jon Nazareth]

Good evening to anyone that's not watching 'Bakeoff',

I've now received a quote from SCISS Ltd for a set of frames for the Stirling Single.  These comprise the main, bogie and tender frames in 2mm mild steel for £47.95 inc. of p&p.  Not thinking, I asked for 2mm as this is what the original 2 1/2 gauge used but that was for a steam model.  It can easily be reduced to 1.5mm if need be.  The purpose of this post is to ask if anyone else would like a set frames.  I will contact SCISS just to let them know that I've received the quote and am waiting for any further interest from G3 members.

Regards
Jon

[blagdon]

Jon, is 'Bakeoff' a telly programme about enamelling the metal sides of passenger coaches similar the process I believe Curlew Models use?

Ian the Gauge '3' Pirate