Finney 'Duke' in 7mm - 9083 'Comet'

[Steph Dale]

Thanks to Cynric (28ten of this parish) I should shortly be receiving a 7mm scale Finney 'Duke' and 2500g tender kit to build a model of 9083 'COMET' as running c.1950; i.e. just before it was withdrawn.

I know little about GWR locos, but enjoy Martin Finney's kits so finding evidence of the locos continued use on the MSWJR and DNS it became a bit of a 'no brainer'.

I'm now starting to look at what additional parts may be required; including everything the provision of a good motor/transmission (courtesy ABC, I guess) through to some of Laurie Griffin's tapered handrails and a small handfull of parts from CPL.  I'm also wondering about some of the constructional details of the prototype.  If it's possible, I'd appreciate some clarification of the following:

Did GWR locos of this era have their cranks set for left-hand or right-hand lead?
What lot numbers covered the Dukes, especially 'COMET'? (So I can order the correct GAs from the NRM)
What shape should the inside cranks be? Oval, elliptical, etc (dodecahedrons for all I know!)
Would the inside and outside cranks be in line/opposite/some other position?

Are there any books or magazines I should be trying to obtain that would help with my 'education'?

If you're all happy to help me along I'd like to do the build here when the time comes and pick up your thoughts and guidance on the way.

Many thanks for any and all help,

Steph

(Post modified because I failed to identify the correct tender for the umpty-umpth time; I think it's correct now!)

 

[28ten]

Finney 'Duke' in 7mm - a potential workbench project

Thanks to Cynric (28ten of this parish) I should shortly be receiving a 7mm scale Finney 'Duke' and 3000g tender kit to build a model of 9083 'COMET' as running c.1950; i.e. just before it was withdrawn.

I know little about GWR locos, but enjoy Martin Finney's kits so finding evidence of the locos continued use on the MSWJR and DNS it became a bit of a 'no brainer'.

I'm now starting to look at what additional parts may be required; including everything the provision of a good motor/transmission (courtesy ABC, I guess) through to some of Laurie Griffin's tapered handrails and a small handfull of parts from CPL.  I'm also wondering about some of the constructional details of the prototype.  If it's possible, I'd appreciate some clarification of the following:

Did GWR locos of this era have their cranks set for left-hand or right-hand lead?
What lot numbers covered the Dukes, especially 'COMET'? (So I can order the correct GAs from the NRM)
What shape should the inside cranks be? Oval, elliptical, etc (dodecahedrons for all I know!)
Would the inside and outside cranks be in line/opposite/some other position?

Are there any books or magazines I should be trying to obtain that would help with my 'education'?

If you're all happy to help me along I'd like to do the build here when the time comes and pick up your thoughts and guidance on the way.

Many thanks for any and all help,

Steph

Right then!
Books
GWRJ Spring 2008 no 66 is essential reading and GWR standard gauge 4-4-0 pt1 (OS Nock) contains some very good drawings including the motion (which is set opposite to the crank, I cant remember if it is left or right lead) and I have loads of miscellaneous pictures in my book collection  8)
The correct inside cranks are in the box  Motor gearbox is an ABC, the recommended unit is in the instructions.
There is not a great deal that needs to be replaced, Griffin washout plugs are one thing I would go for,but the biggest change I would make is to make a copy of the boiler and firebox in N/S to get rid of the half etching and boiler bands (A pet hate of mine) and to make it a little more robust.

 

[Steph Dale]

Finney 'Duke' in 7mm - a potential workbench project

Cynric,
Thanks for the help - I'll have a spin through the dealers for that GWRJ; a lovely publication, for years I was wishing for a Southern equivalent until Kevin Robertson stepped into the breech...
I think I can snag a copy of the O.S.Nock book from my Dad, he built a Javelin 'Dukedog' a year or two back and has all sorts of slightly random research materials for the class.  I'll check when I next see him.
I'm pleased that the kit will take a stock ABC; smooth running is almost guaranteed and I've got a 'spare' maxon 1530 somewhere round here which should work and fit well. 
Point noted on the boiler.  I've just about finished doing a 10 000mile service on a friend's Finney 'Bulldog' so he lent me the instructions: I was surprised at the kit coming with etched boiler bands as I think they generally look rubbish and the LSWR locos Martin does come with the option of plain boilers.  In this case my normal trick is to (re)roll the parts inside-out and replace any surface features, so your recommendation of the washout plugs has been taken, with many thanks.  I'll have a think about a wholescale replacement of the boiler and firebox wrappers when I've got the kit in front of me.
In terms of 'stock ammendments' I would probably replace the couplings and crankpin nuts with items from CPL, fit my own 10BA crankpin and bush sets, use Laurie's tapered handrails (if applicable to the prototype?) and have a good look at things like the cab interior.  I often use split axles in my models, but appreciate that on this loco that could take a lot of thinking...!
Steph

 

[28ten]

Finney 'Duke' in 7mm - a potential workbench project

I do rather like the Southern way, its just a bit expensive for a casual buy. Simon (Titfield thunderbolt) Castens can get the GWRJ back issues.  Apart from the boiler band issue, I just find that half etched boilers are a bit fragile and prone to small dents and I always replace them, but Finney castings are pretty good on the whole. Thinking about it I would also look at some Laurie Griffin castings for the expansion link and possibly the eccentric rods, it depends whether you prefer proper forked joints. Split axles? rather you than me!! 

 

[Steph Dale]

Finney 'Duke' in 7mm - a potential workbench project

Cynric,

I must admit that I'm not too worried about the odd dink in a boiler for modelling a GWR loco in the fifties; most of them were in attrocious condition then!  I've got a photo of a 2251 hereabouts that was taken in 1950 where any trace of livery is invisible behind the dirt and the bonnet over the safety valves is missing...

Point taken on the eccentric rods, etc - I've got those parts in stock for the Finney T9(s) as well!

Split axles aren't so bad; a little extra effort during the build and then no need for any maintenance seems like a good trade-off to me.  S'funny how these things go in cycles, there's a thread running on the G0G website at the moment on exactly the same subject.  My first method is seen here: http://www.euram-online.co.uk/tips/splitaxle/splitaxle.htm although now in need of an update to cover another two methods we're using for axles when gearboxes are mounted to them.

I still can't see how I'd get them into the loco or tender chassis if it assembles anything like the Finney 'Bulldog', but it should be a breeze to fit the front bogie with them!  Mind you, the cogs are already spinning on suitable methods for making the outside set of frames removable from the chassis.  If I crack that, I'm in with a chance 

I'd still have to work out how on earth I was going to make an insulated crank axle.. .  :-\

Steph

 

[3 LINK]

Finney 'Duke' in 7mm - a potential workbench project

Hi Steph,

You are a braver man than me reference the split axles plus inside motion  :scratch: surely life is to short and maybe American pick up system instead? Just a thought, anyway I look forward to the build when you find the time.

ATB,  Martyn.

 

[Steph Dale]

Finney 'Duke' in 7mm - a potential workbench project

Martin,

You are, of course, quite right - an electrically split crank axle is not impossible; but it is tricky and likely prone to failure, especially if it's me making it!

However, I will be persuing the thought of split axles on bogie and tender.  There, that's almost sensible... 

Steph

 

[Simon Dunkley]

Finney 'Duke' in 7mm - a potential workbench project

Split axles and inside motion is certainly possible in 7mm scale, as Trevor Nunn has done this in S on 3 locos. The cranked part of the axle is electrically dead, with (for want of a better word) pegs extending out into tufnol sleeves which themselves are shrouded in tube which forms the part of the axle carrying the wheel and also runs in the bearing.

Can't be done without a lathe, though!

Here is a shot of his GER T26 (LNER E4 to the ignorant!) chassis - the motion bracket is soldered to a couple of pieces of thin PCB, the captive nuts on this are insulated from the motion bracket with a cut in the copper surface. The whole unit is therefore removable from the chassis along with the wheels.

 

[Steph Dale]

Finney 'Duke' in 7mm - a potential workbench project

Right, I'm back, kit in hand.  Thanks Cynric; I picked it up from the post orifice this afternoon...!

I have had the chance for a scan through the instructions. Referring to a couple of pictures I have to hand sorting the loco details out seems fairly straightforward.  But once again I'm a bit out of my depth on the tenders, although I'm pretty comfortable that the 2500g version is correct for the loco in question...

Referring to the notes in the tender kit (and the OPC books referred to) it appears that 'Comet' has one of the earlier style of tender which has been modernised (the drop in the height of the coping near the cab is the give-away).  It appears to be from one of the series built without water pick-up, but I can clearly see handles/standards on both sides of the front of the tender, so am I correct to think that this means the water-scoop was fitted later?  If so, can I also assume that the tender would have a 'dome' rather than a combined box and filler?  Are there other details on the tender I will be able to see or can form some assumptions around when the only views I have are front 3/4 views?

I look forward to any/all replies.

Steph

 

[28ten]

Finney 'Duke' in 7mm - a potential workbench project

Its pure conjecture but I would go with the Scoop with box and filler. Have a look at the picture in 'the 4mm engine' p29 there are a few examples there. also have a look at P62/3

Im glad it arrived safely, I never quite trust the post office  :scratch:

 

[Graham Powell]

Finney 'Duke' in 7mm - a potential workbench project

Hi, If you go to my website www.highbridgelocoworks.com and click on the Gallery. The 2nd picture shows a GWR Dukedog I built which broke down into several pieces.
The outside frames etc were fixed to footplate. I cannot remember now what sort of pick ups it had. Not split axles but possible engine/tender. I built it for an old chap who only ran it once before passing away. It was sold at an auction for a very poor price. I often wonder what happened to it as I would not have minded getting it back!. It look marvellous going round the garden. Maybe if there is time I'll build another one..... ( fat chance!).
A friend of mine built "Comet" many years ago. When virtually everything in gauge O was hand made and it was a lovely model. Again I wonder what happened to it as it was very well engineered and ran like a watch.

regards
Graham Powell

 

[Steph Dale]

Finney 'Duke' in 7mm - a potential workbench project

Cynric,

Thanks for the thoughts - if I don't find anything more concrete I shall proceed as you suggest.  BTW - the book you refer to is the Guy Williams one I think?  Maybe I should try and get a copy.

Graham,

My Dad's Javelin 'Dukedog' come apart in much the same way as your model.  I'm still umming and aahing about how to split the loco's outside frame from the body and/or chassis.  Looking through the instructions I can see why it's designed to fit to the chassis as this allows the outer hornblocks to actually work.

Todays questions:  :wave:
Is it worth me trying to get hold of a copy of the relevant RCTS publication for details on this loco?  If so, which one do I need?
In the absence of injector detail, do I need two live injectors, or one live, one exhaust?
Would/could the tender have gained vacuum brake during its rebuilding?  I've not come across steam brake on a tender before and as most GWR tenders were vac braked I'm pondering...

I'm looking forward to any/all replies!

Cheers,

Steph

 

[28ten]

Finney 'Duke' in 7mm - a potential workbench project

The RCTS book isn't essential, the OS Nock book is a better bet, as is the GWRJ, the Guy Williams book is the 4mm engine, essential reading for any scratchbuilder.  Yes you will need to fit the vac cylinder

 

[Dog Star]

Finney 'Duke' in 7mm - a potential workbench project

For your period, two live steam injectors... probably both of the "8X" type.

I have the RCTS part for this class and I think that GWRJ has better photo coverage plus a frame plan. What you will get from RCTS is the historical details relating to the fixtures and fittings of the class generally and individual engines specifically.

 

[Steph Dale]

Finney 'Duke' in 7mm - a potential workbench project

Very many thanks to all for your help, and with the current round of enquiries.  The postman delivered some useful books yesterday and I've had this morning to indulge in some headspace and the Duke GAs in Part 1 of Great Western 4-4-0s.  Fascinating stuff!

I've also re-read all the posts in this thread and had another read through the Finney instructions for the tender.  And I'm beginning to see what I should be doing and can forsee the moment that the first parts will be popped out of the fret and the soldering iron fired up.  I think the list of extras looks like this and would welcome your comments:
New items: Injectors (Hobbyhorse), Tender vac cylinder (Hobbyhorse), X-head vacuum pump (Hobbyhorse), Tapered handrails (Laurie Griffin), Washout plugs (Laurie Griffin), some valvegear components to supplement Finney parts (Laurie Griffin), Couplings (CPL), Crankpin nuts (CPL/Mitchell), Plates (Severn Mill).  I'm going to have another look at the chimney too, if I need a new one (Dukedog type) I'll get it from Springside.
Modifications: Split axles on tender and loco bogie, replacement ashpan (so that plumbing goes around, not through), plumbing, reversing lever, tender water valves.  Use of a Meteor hornblock set on the rear axle.
Decisions still to be made: (oh for a good rear 3/4 view!, but will take under Cynric's advisement) tender top details for water scoop and filler.  And where on earth the vacuum reservoir should be for a tender converted to vac brake...

It's got me quite enthusiastic now!  Just wondering whether to add a 'Dukedog' (9015) and/or 'Bird' (Nightingale or Skylark) to the pile: the GWR form of TDS (Tender Detail Stress!) notwithstanding!  I'm looking forward to Simon coming up with the goods on a couple of GWRJs too...

Steph

 

[Steph Dale]

 

[Dog Star]

Steph,

  In pursuing information about curved frame Bulldogs for use in construction of a Finney 7mm kit (to be Pegasus circa 1912) I came across some good, detail, photographs which were taken during the most recent overhaul of Dukedog 3217.  See here for photos with captions:-

http://www.rhbnc.ac.uk/~uhaa009/bb/loco ... _news.html

Many of the photos on the "old news" web pages can be found in a gallery where there are options to download larger images, here:-

http://www.rhbnc.ac.uk/~uhaa009/bb/pics ... _3217.html

OK, so this is Earl of Berkeley and not Comet....  however, the detail is worth study.

regards, Graham

 

[Steph Dale]

Graham,

Many thanks for the links - as you say, lots of useful views and info there.  I note that the inside cranks are a different shape on the Dukedogs, the same oval shape as on later 2251s, rather than the elliptical pattern used on the Dukes (and, I assume, on the Bulldogs).

The curved frame Bulldogs are very attractive locos; it's a shame that the last survivor didn't quite make into the period or location for the layout!

I will also keep this in mind if I manage to firm up the options for building a Dukedog...

Cheers,

Steph

 

[Dog Star]

Many thanks for the links.

I note that the inside cranks are a different shape on the Dukedogs, the same oval shape as on later 2251s, rather than the elliptical pattern used on the Dukes (and, I assume, on the Bulldogs).

Steph

  Humm, assume?  no such word when it comes to GWR engines as a consequence of (a) the policy of standardisation for most parts and (b) the continuing development of existing practices.  What this means is that parts introduced for one class often got used on other classes (that is:- for engines which could have been built earlier or later and that does not just apply to boilers...  try reading the numbers which are stamped on the motion / axleboxes of preserved GWR engines).  In the case of the Earl on the Bluebell, as a Dukedog this represents an engine nominally built in the 1930s from parts of engines which were built at least thrty years earlier.  So what the photograph shows is a crank axle which probably came from a Bulldog or was made to the design which was used for the Bulldog class.

  As far as I am aware, there is nothing special about an elliptical crank compared to an oval crank with the same width and centres.  This is an example of where Swindon could (would?) have simplified the manufacture of the crank axle by changing the crank shape from an ellipse to an oval.

regards, Graham

 

[Steph Dale]

Hehe, it's a fair cop guv ;-)

I may have mis-read things from the (very scatalogical) research I did for my 2251.  It soon became pretty obvious which locos had second-hand (Dean goods?) wheelsets (elliptical cranks in line with wheel cranks) and which had been built with new wheelsets (oval cranks opposite wheel cranks) - their balance weights were a good indicator.

From this I 'leapt' to the oval crank being associated with Collett, but I agree it's equally likely to have just been a works development; the elliptical cranks certainly being earlier and harder to shape/machine (easier to 'strap' though!)

Assumption is certainly 'the mother of all cock-ups' as I've heard said, at least Swindon had some standardisation; the early products of Eastleigh are a real pain and I can find some evidence of as many as four patterns of crank axles employed on the T9s, for example.  I suspect that either pale into insignificance when compared to Craven-era LBSCR...

Steph