Tuesday, 4 June 2024

HR 118... Progress So Far



Photo reproduced courtesy of HRSoc/Am Baile

There are only three extant photos of HR118 and a side elevation based on them drawn by Laurie Ward, which results in some blank areas and uncertainty about several features of the engine, which causes difficulties for the modeller. Probably the most mystifying feature, seen above, is the "upper bunker", or "coal chute", which appears to be attached to the rear spectacle plate, about level with the driver's left elbow. This is not included in the Ward drawing, nor was it part of Peter Kay's early 4mm kit for the engine. Sandy Harper's model of the engine which featured in the GOG Gazette of Aug. 2013 is a useful reference; he included the "upper bunker" as an exterior feature, though offered no solution to the interior arrangements.

The design of the prototype engine allows for a 3/4 ton bunker at the rear of the cab, filled presumably by means of the outrageously tight 3" opening between the spectacle plate and the back of the bunker, the spectacle plate would have been cut away below the top of the bunker rear to allow coal into the bunker. 

It is possible that the upper coal chute was added to allow a wider (about 6") ingress for coal. However, in that case there would have been a corresponding opening in the spectacle plate inside the cab to allow the coal into the bunker below, which appears to have had a top plate or shelf. Some contrivance would have been necessary to stop the coal simply spewing all over the cab, and this is not evident in the photographic record. In particular the photo of 118 on the scrap line at Culloden in 1923 shows no evidence of an upper coal chute inner opening; perhaps this curiosity was removed as impractical. Anyway, I decided not to include the feature in my model. 


Cab rear showing the narrow opening for loading coal into the bunker. 


As you can see above, though I've no evidence for this, I've modelled the side tanks continuing into the cab which also enclose the rear driving wheels. The back-head is attached to an inner front spectacle plate which can be removed for detailing. There is little evidence for the cab interior so it'll be based on probability. Castings for the back-head fittings are proving elusive, available items proving oversize.  



Chimney (Lochgorm) and dome (LGM) still need some refinement around the base.


 Initially interpretation of the photos of 118 led me to build the side tanks without the plate which covers the gap between the inside of the tanks and the boiler. I thought that what the photos showed was an attachment bracket rather than a complete top plate. However the large gap between the tall side tanks and the boiler led to a re-think and I modelled a wider top, which covers the gap and it looks better too. 

Under the cab, between the frames I've built what I think is a well tank to fill the gap. It's a convenient space to add weight which has vastly improved haulage capability.


The cab steps are attached to a cross member fastened to the frames. A sand box sits behind the steps and another one behind the motion plate, I need to make patterns for these and also the tank top water fillers and cast them in pairs.  


I'm working on a driver and fireman to suit the engine and the wee dog is under way too, these will be available to modellers as castings as soon as I've completed the moulds.


HR118 at Culloden out of service 1923 photo HRSoc/Am Baile.
The rear of the cab is well seen in this view though there is no sign of an interior opening for the upper coal chute. The position of the brake standard suggests the engine is right hand drive.