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Remodelling a B12

Posted: Mon Oct 11, 2010 5:53 pm
by 60526
It seems as though my pockets aren't as deep as some, I went for a Crownline B12 enhancement kit the other day on e-bay and blinked before it went for £62. I don't know whether that's a reasonable price or not, but you have to draw the line somewhere. It's £103 for the complete PDK kit, perhaps one day.
I've already started to cut the Hornby body around, it's now down to running plate, splashers, smokebox and cab, I'm not aware that an etched chassis exists, so I'm going to scratch build the chassis, make the boiler out of brass, make new steps and have a long think on how to extend the running plate. Not convinced that the smokebox door is correct, but like the chimney and dome, where can you buy casting for such a model these days?

Re: Remodelling a B12

Posted: Mon Oct 11, 2010 6:08 pm
by Atlantic 3279
For chimneys (and maybe domes too) I would try Gibson or DMR. Also consider the Hornby B17 dome available as a spare from East Kent Models.

Re: Remodelling a B12

Posted: Mon Oct 11, 2010 6:24 pm
by Atlantic 3279
In fact, if you are aiming for a scale B12/3, then given the lack of GIRTH, as well as lack of length that affects the Triang/Hornby B12 boiler moulding, is it worth thinking about grafting on a whole spare B17 boiler instead, making a new smokebox by adding wrappers as I did on my K4 model, and using the Dave Alexander K4 smokebox door which appears potentially suitable too? I might actually try that on my own B12 some time, now that the idea has come to me.
Have a look back through my modelling thread for the K4 if you wish to see what I did.

Re: Remodelling a B12

Posted: Tue Oct 12, 2010 1:21 pm
by 60526
Thanks for the response. Might see Mike Russell (DMR) at Peterborough next weekend so will see if he can help. Was certainly looking at a B12/3, I'll look at the B17 boiler, could be a good option, but I'm still thinking about scratching the boiler, the Hornby smokebox certainly looks small, so that would have to be new as well. I wonder if the smaller Hornby boiler as it is would suit a B12/4?

Does anyone know if the Gibson wheels for a B12 have that distinctive spoke design. I've been referred to Tony Wrights articles on the PDK and Coopercraft B12, I've got them somewhere, apparently one was fitted with Gibson wheels, the other Markits.

Re: Remodelling a B12

Posted: Tue Oct 19, 2010 1:21 pm
by 60526
If anyone is interested, the Gibson wheels do have the distinctive spoke design of the B12. Just wish that somebody hadn't invented the flexible friend, I ended up buying the PDK kit. It had a good wright-up in BRM and the etches and castings etc look good quality.

Without inventing a new posting, I bought one of the old Kirk short wheelbase non-corridor parcel vehicles, it should run on Fox bogies I understand. If so, by who?

Re: Remodelling a B12

Posted: Tue Oct 19, 2010 1:52 pm
by mick b
MJT do 8ft Fox

Re: Remodelling a B12

Posted: Wed Nov 17, 2010 1:40 pm
by Atlantic 3279
Atlantic 3279 wrote:given the lack of GIRTH, as well as lack of length that affects the Triang/Hornby B12 boiler moulding
Now I'll eat my words, well, sort of, anyway....

I've seen the Hornby B12/3 boiler moulding criticised, in print, on more than one occasion, for being too skinny. Having measured the moulding by Vernier at 22.8 or 22.9mm diameter (or a bit less than the scale equivalent of 5' 9") I was inclined to agree, given that the boiler barrel beneath the cladding was supposed to be 5' 6" diameter at its largest. It does seem to allow very little for the thickness of the cladding.
HOWEVER, I've also today measured the following models' boiler diameters, and all of these are locos with 5' 6" boiler barrels + cladding:
Hornby B17 ...23mm
Hornby D49 ...23mm
Bachmann J39 ...23mm
Bachmann B1 ...22.8mm
As I have never seen any suggesting that these four models have unduly skinny boiler mouldings, I am now unconvinced of the significance of any error on the Hornby B12/3 - unless somebody can tell me definitively that the real B12/3s had unusually thick boiler cladding!
My own thoughts of re-boilering a B12/3 in order to increase the girth are now abandoned, or at least on hold, as it seems to me that even though it possibly has the right firebox plugs, a B17 boiler substitution would make hardly any difference. I may as well just lengthen the existing B12 moulding.
Do any of you happen to have reliable drawings of the B12/3 or other classes mentioned, showing a dimension for the boiler cladding diameter? That would settle the issue.

Re: Remodelling a B12

Posted: Thu Nov 18, 2010 2:18 pm
by PaulG
Atlantic

Have a look on the GERS web site and check both the "Sales" and "loco" links :

http://www.gersociety.org.uk/index.htm

Paul.

Re: Remodelling a B12

Posted: Fri Nov 19, 2010 2:32 pm
by Atlantic 3279
Thanks for the link Paul. I've had a look but not so far found any answer to my question(s).

Re: Remodelling a B12

Posted: Fri Nov 19, 2010 8:55 pm
by Pebbles
I'm new to this. Firstly the Hornby B12 has significant compromises in particular with it's footplate, this makes it difficult to remedy. The only drawing worth viewing, other than works drawings, are those supplies by the GERS. The Isinglass drawing was derived without the benefit of at that time a suitable reference, and John used the B17 boiler diameter as a basis. The GERS can supply a DVD with a number of drawings with the option of printing off at 4mm or 7mm, I would strongly advised obtaining this. The answer to the query is 5ft 10inches or so, (23.5mm) making the Hornby boiler .7mm undersize. Then there is the undersize smokebox door, I have always believed that the Hornby B12 appears to offer more than it can deliver. Best of luck.

Re: Remodelling a B12

Posted: Sat Nov 20, 2010 8:57 am
by Atlantic 3279
Thank you Pebbles, that is useful comment. I realise of course that there are also errors in the small matters of wheelbase and coupled wheel size!

Re: Remodelling a B12

Posted: Mon Nov 22, 2010 9:55 am
by madusjockus
As my first contribution to the group [ I'll bore you guys to death later!] the link for the GER material is here.

http://www.parishchest.com/g.e.r._drawings__P90709

Might get a copy myself as it covers a couple that I would like to build when time permits.

Cheers
Kev

Re: Remodelling a B12

Posted: Sun Nov 28, 2010 12:57 am
by madusjockus
As a sort of follow up- for those really wanting a blue B12 the only real route is to convert it back to the basic B12 or S69 as it was designated by the GER.
I came across an article from a 1966 Model Railway Constructor in which a guy successfully converted one back to this version- very nice it looked too in its GER blue with red lining and light coloured cab roof.
There is some good LNER coach stuff in these mags as well although it mainly concentrates on GNR/LNER coaches.

HTH
Cheers
Kev

Re: Remodelling a B12

Posted: Sun Nov 28, 2010 10:56 am
by coachmann
It's like asking an Irishman the route to some place, and him replying "Well sir, if I were going there, I wouldn't be starting from here".

Triang/Hornby produced toys pure and simple, and took liberties with just about every model they produced to partiallly compensate for having a much higher buffer height than "scale". Therefore the 'step' from the lower running plate to the higher section is too shallow and, if that cannot be altered, there is no point in going any further. The tender frames too are vertically stretched so that the running plate matches up with that on the loco. Of course, if one is happy with the running plate, there is no point in bothering with scale drawings.

Re: Remodelling a B12

Posted: Sun Nov 28, 2010 11:49 am
by 60526
On this thread I earlier posted that I had bought one of the old Kirk short wheelbase non-corridor parcel vehicles and implied that the kit did not have Fox bogies. Well just to put the record straight the kit is one of the newer Coopercraft kits and it does come with the Fox bogies and the quality is very good, but of course doesn't have the weight of the whitemetal bogie.
Back to the B12. I'm not going to argue about the shortcomings of the Triang/Hornby B12, the moulding must be quite old now, but since my original posting I've seen 2 layouts both with a PDK B12, one was OO, the other EM and both had Romford/Market wheels. The wheels on the real thing are quite distinctive and after spending all that money on the kits, this is what let them down. So I know some don't like Gibson wheels but I'm going to use these when I make my kit up.
So is there anything else wrong with the Isinglass drawing?