Tuesday 19 November 2013

HR 57 Details


HR 57 mechanism and wheels.


I commissioned an etch from John Firminger, from drawings I made, to simulate the solid center drivers. The spokes have to be cut away a little towards the crankpin boss to seat the etched plate which is then glued in place.

I used part of the same etched discs for the outer wheels though I reversed them and cut them to shape so they covered the four spokes opposite the crankpin. I filed the irregular (trapezoid) opening between the outer spokes to shape, cut the spokes down to seat the plates and glued them in place. Later I filled the openings with Milliput, filling between the spokes with the modelling putty, then I made the shallow recess behind the openings with the wrong end of a small drill which made a good modelling tool for this job.

Behind the rear wheel, inside the frames, is the vertical brake shaft which connects to the brake standard in the cab. Just outside this is what I think may be an injector, I can't see the complete mechanism in any photos that exist, so as I didn't want to leave it out, I resorted to "imaginative reconstruction". It will lurk behind the cab steps in the shadows under the footplate so I think I'll get away with it!

The coupling rods are not the correct profile, they should have raised bosses, however I think the rods need to be filed away between the crankpins to make the bosses, otherwise, if I add metal, they'll be too wide.


HR57 chassis details

At the back, behind the rear wheel, a brake cylinder connects to an arm which is attached to the horizontal brake shaft which runs just in front of the rear well tank. A return spring passes from the arm under the cylinder and anchors to a vertical plate. I'm uncertain about this last detail as it's hidden in shadow under the footplate on photos which are the only reference. Charles Wrigley brought my attention to this mechanism and provided me with information to help model it from his forthcoming article in the HR Journal on braking systems of the Stroudley Tanks.



 
 
 Lochgorm Tank backhead arrangements.


Photos provide only a tantalising blurred glimpse into the cab of the Stroudley tanks; however, I think the reversing lever on the left is correct and so is the gauge on the cab front plate, though the rest of the detail is of necessity a "reconstruction". Some castings from the LGM range were used on the backhead, helped along by some scratch-built parts. The irregular plate on the cab floor will support a wooden planked floor soon ; a suitable crew is under way too.

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