Rare Post Card of HR23 Discovered

 

Click on the image to enlarge. 

I recently purchased this fine high-resolution post card image of 23 on ebay for a song. It's a little known image of this Scrap Tank and shows the engine in its early days at Perth, still in its original livery, with the company title in full on the side tanks. There are signs of wear and hard service which would suggest the picture was taken some time after the engine entered service in 1903.

The photo cropped up after I'd finished construction of the engine and resulted in a few retrospective additions, which would have been easier at the outset, nevertheless these details though minor, added a satisfying completeness to the model.

The interior of the cab is partially visible, revealing an upright rod topped by a winder, affixed to the front of the inner bunker which the fireman or driver has his right hand on; I think it might be a water valve. Whatever it is, it was worthwhile adding to increase interest in the cab interior.

Behind the cab step can be discerned the downward extension of the brake column, masked by the crew member. I added this elusive detail, which rarely shows up on photos, along with its link to the rear cross-member, which completed the brake rigging of the engine.

If you look closely at the cylinders I think you'll agree that they are not a pair as the nearside has a rivetted cover and the offside a plain one. I did not model this oddity as I think it was probably a temporary one and in any case my model represents the engine after 1919, in its days in service at Inverness. By this time the livery would have been updated so that only the initials H . R appeared on the tanks and I'm sure the cylinder covers would have been regularised by then.

Of interest also is the buffer beam, which doesn't seem to display the usual insignia, though this may be due to wear. The cylinder drain-cocks are of an early pattern and are not linked together. On the plate between the cylinders there is a curious central triangle of bolt heads; I modelled these just for fun.

I'd be interested to hear from any member who has a copy of this photo or has seen it before anywhere.   

HR23 Scrap Tank, construction complete

HR23 construction complete

Externally construction is complete, it remains to detail the cab interior, add the crew and coal the bunker. A two part article on modelling a Scrap Tank will be published in the next two issues of the Highland Railway Society Journal; part one will deal with construction up to the point seen in these photos, while the second will describe finishing and painting.   

I'm still working on the large rivetted balance weights which are a prominent feature of the wheels and need to be convincingly modelled. I think the solution to making all six similar might be to have them 3D printed. The sand boxes, which scan be seen on the footplate above the cylinders and below the cab at the rear, were carved individually from scrap resin castings; only the chimney is a 3D print. 

The sand boxes fit snuggly under the footplate behind the cab steps

Detail of marine type big-end of connecting rod and back to back brakes.

The back to back brakes between the front and center drivers presented a problem because of the restricted space available in model form, less than in reality because of oversize flanges and the need to allow clearance between brakes and wheel treads. A good deal of trial and error resulted eventually in the rather squeezed design shown above.

Scrap Tank, Superstructure.

Construction of the superstructure of my Scrap Tank is well advanced and all the sheet metal parts needed to complete it are cut out now and piled on my desk, just like the parts from a kit, though without tabs and slots. With the superstructure mounted on the chassis and a chimney in place it now becomes evident that the Scrap Tank, especially when compared to my previous project, little 118, is quite a monster. The chimney in view is temporary as it is planned to replace it with a more accurate 3D printed one, a job currently in the hands of a collaborator. A casting from LGM resolved the problem of the dome and a pressing from the same source will go a long way towards a convincing representation of those side by side safely valves with the whistle rod between them. I made the boiler and the smokebox as two separate assemblies, though in retrospect I think it would have been simpler to use a smokebox wrapper over an extended boiler cylinder. Near to scale boiler bands were supplied by Hobby Holidays and a curl of 0.8 wire fills the step between boiler and smokebox. Cut-outs were progressively enlarged in the footplate to allow free movement as the coupling rods and the substantial bosses of the connecting rods move above the footplate. Apart from the chimney, for which I could find no suitable match, all the castings I need to complete the model are from the accessory lists of  Laurie Griffin and from 62C Models. Laurie's accessory list includes an extensive range of Highland Railway bits and pieces without which modelling Highland locos, with or without a kit, would be difficult indeed.  

The driving wheels, being re-used ones from old 2-4-0 engines, are larger than one would expect on a tank engine and extend into the cab and partly across the entrance. 

Wide splashers will accommodate the coupling rod bosses and cover the tops of the front drivers above the footplate. This should improve the appearance of the loco, who's proportions are somewhat marred by the outsize wheels. In addition, a whole raft of castings and details are yet to be added, which will greatly improve the look of the engine. Note the "L" shaped trim between the boiler and spectacle plate. This started life as an "T" shape, which can be bent to fit the curve of the boiler, which an "L" shape can not. The curved "T" is easily filed to the required "L". 

An etched back-head from the now sadly withdrawn "Lochgorm Kits" range is in place between the cab side tanks. There is an inner spectacle plate, to which the back-head is attached, allowing the assembly to be removeable. Note the covers over the rear drivers where they protrude into the cab. Some consideration needs to be given to the floor level to close the gap under the back-head.

Scrap Tank, construction progress.

Construction of the chassis of my 7mm scale Scrap Tank is well advanced and the mechanism progresses smoothly under power along the test track in the studio, so a test run on the club layout in Carlisle at this stage might be a good idea. There is still much detail to add below the footplate which I will leave for a later stage of construction; meanwhile I'm looking into the possibility of 3D printing some components, particularly the sand-boxes and driving wheel springs and maybe the rivetted wheel balance weights. The coupling rods were made for me by WMI; the connecting rods I built myself. The gearbox is an ABC Mini7E mounting an M1833 motor. The footplate assembly is screwed to the frames through the front frame spacer; the rear frame spacer slots into a housing fastened to the inside of the back buffer beam.

Phosphor-bronze pick-up wires (0.5mm) are arranged to bear on the tops of the centre and rear drivers which will locate inside the engine's spacious side tanks; those that bear on the front driver have not been resolved yet. The left hand driving wheels are shorted by means of an 0.5mm p/b wire soldered between hub and tyre and slotted behind a spoke.

With the front driving wheels are in position, the axle screw is masked by the slide-bar/cross-head assembly and inaccessible. To overcome this the axle and its brass bearings is retained by a keeper rod soldered to a plate. The removable plate slots in place against the front frame spacer and is retained by a screw. 

Clearance between the chunky cross-head casting and the coupling-rod is minimal and much metal had to be removed warily from the rear of the casting and from the head of the protruding crank-pin screw to achieve free movement.