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Good progress on the M7 mods, the 32g of mazak ballast in the side tanks - most of it behind the rear coupled axle centre - gone; and now just coming up to 40g added, all of it forward of the same axle centre.As an 0-4-0 it's nearly balanced in the middle of the coupled wheelbase now, and there's some small fiddling pieces of lead to go in well forward yet, and if I can find a brass or whitemetal chimney to match the pretty fine Hornby piece, that will go on as well.

I have rewired the loco too, partly to eliminate use of the chassis block in the current path, but primarily to completely declutter the front of the model for more weight by routing the driving wheel pick up wires to the rear; the hardwired decoder will be at the rear of one of the side tank voids.

The bogie will be arranged to simply trail around, not supporting the rear of the loco at all, so no lifting weight off the drive wheels which significantly reduces the traction of the model as supplied. I am searching for a couple of split axle 10 spoke circa 14.3mm diameter, so that the bogie can be modified to collect current with no wiper drag; I know I had some off worn out Bachmann split chassis locos, now where did I stash them....
 

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Discussion Starter · #42 ·
An interesting 'neverwasser' something I am always considering I have tried to work out a GCR 2-6-2 tender loco but the 2-6-2 needs a longer body than an equivalent 4-6-0, I suppose the other loco I always liked was the A2/1 based on the V2 but with the Thompson valve set up, only 4 of these but they were said to be amazingly free runnersanyway I have to get back to the OO layout soon as the OO9 is all but finished - yes - well possibly 'cos every time I say this I find more to do.
 

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There's an outline diagram of a Robinson 2-6-0 in the Haresnape volume on Robinson Locomotives. Looks like a 'Director' on 5'8" wheels with two outside cylinders. Would near enough build itself on the basis of a 'best fit' mogul mechanism, (from a K3 would suit) O4 body, (modified by shortening the boiler barrel and footplate circa 12mm) cylinders and connecting rods, and tender. Fair bet that this would have been a success, it looks very right.
 

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... progress on the M7... The bogie.. I am searching for a couple of split axle 10 spoke circa 14.3mm diameter, so that the bogie can be modified to collect current with no wiper drag...
Well that idea is canned, split axles too thick for the bogie frame to safely accomodate, hey ho, we have to sacrifice 2 grams force worth of traction to the bogie wiper drag.
 

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Discussion Starter · #45 ·
Yes this is from George Dows books on the `Great `Central, Vol 3 the other interesting drawings were for a USA inspired 2-10-2 which looked very large for sure and the other for a more obviously Robinson 2-10-2 this having 2 cylinders whilst the Baldwin had 57 sq ft firebox the Robbo version was also looked big but cylinders of 26 x 30 and tractive effort of 62,000 lbs just about, and boiler pressure of 200 lb/sq in.

To go along with this monster was a 0-10-2 tank a butch 0-8-4 version would have coped at Wath no doubt.
 

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Discussion Starter · #46 ·
Ah correction the drawing of the Gorton Mogul was reproduced in W A Tuplins book, 'Great Central Steam' i looked at this again, rather a 2-6-0 version of the D10 and clearly inspired by the GWR mogul with standard 26 foot grate and a slightly shorter boiler it would have been a great steamer with a ratio of about 50:1 (heating surface to grate area) instead of the big 4-6-0's more like 103 :1 which suggests at 180 lbs boiler pressure they never got warm enough. anyway it never came to pass
 

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Had it done so, I suspect few if any of Robinson's mixed traffic 4-6-0's classes would have emerged; as a circa 28,000lb tractive effort 2-6-0 with the boiler performance of the Robinson 4-4-0's would have been a very useful engine indeed. (It could have followed the same boiler development path as the 4-4-0's, from the 11C saturated to the final superheated boiler on the 11F (LNER D11), and the GCR could have handed over 86 very competent class 5MT units to the LNER, for a lot less money and effort, and a lot more much admired performance; instead of the 5 classes - for a total of 86 - mediocre mixed traffic 4-6-0's.)
 

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Further on the M7, now nearing completion. I have taken weight out of the rear of the body, there's a large blob of plastic under the neatly modelled coal slide - not much weight reduction, but it counts for more in balance terms as it is near the rear of the loco, and have finished adding weight at the front, so it is now very stable.

A spare N2 body was sitting near the M7 while I was doing this, and the size was very similar. Now what if Mr Gresley had decided that the boiler and front end of the N2 might do well in an 0-4-4T format on the GN's branchlines, now that the Stirling G1 and G2 0-4-4T's were nearing their end? And then succeeded in subsequently persuading the LNER locomotive committee that this might be a useful move?

The resulting new LNER G1 is about two feet shorter than the N2, taken from the bunker end as less water is required, so it's purely a coal bunker at the rear, and the balance pipes behind the steps are lost, and sheds the condensing gear too; the weight estimate a branchline friendly 60 tons, with adequate adhesion at 38 tons on the coupled wheels. (As a model there's room for much more weight up front than in the skinny boiler of the M7, so ample traction, and to top it off, the overall appearance is very neat.)

I'll swap bodies back and forth...
 

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Discussion Starter · #50 ·
Thinking a bit more about your views 34c on the GCR really the obvious solution was the B6 or 8N in GCR notation, basically a large boiler O4 (aka O5) of which there were 3 built as 8N's, these locos were highly standardised with the O4/5 group of which there were very many and would have been easy for the sheds to operate and maintain the usual thing with the GCR was the high heating surface value to firebox ratio which was about 80:1 which is a bit weak but for a fast freight loco was about good enough whilst the Sir Sams etc came out over 100:1.
 
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