HR 18 Class, Small Goods.

HR 18 Class, Small Goods No.27 

Construction of this rather difficult prototype is now complete, the model has been built without the aid of a kit, though relying on commercial castings to complete it. Most of these were obtained from Laurie Griffin (LGM) practically all of them were modified in some way or other to suit this engine. The model ran with a light train on the club layout in Carlisle on Saturday where it performed impeccably, without a single derailment, much to my satisfaction.

I modelled No.27 as rebuilt in 1891 by David Jones the Locomotive Superintendent of the Highland Railway at the time and the engine displays many features typical of a Jones engine. No.27 was the last survivor of this class lasting until 1923. A grainy photograph shows the engine forlorn and abandoned at Culloden Moor, the short parallel buffers seen above are attested to by this source.

There was room inside the superstructure for an ABC Gears Mini Gooch with an M1833 motor and flywheel which provides plenty of power for an engine which typically was intended to pull a train of about 15 wagons. Weight is in the firebox between the driving wheels.

No.27 c. 1920

The tender is built from an etch given me to evaluate by Walsworth Models and described in an earlier  blog posting on 7/10/21 as "A tender in search of a Loco ". It was certainly a good help though I don't know whether it will ever see the light of day as a commercially available kit. The Small Goods, Glenbarry and  Medium Goods classes all ran with this tender, so a kit would be most welcome to Highland modellers. 

 

The reversing lever can be seen in this left hand view, emerging behind the sand box. Probably the most taxing problem encountered in building this engine was providing clearance for the cross head in the tight space between the inner and outer frames. The outer frames, front springs and cylinders form part of the superstructure which can be removed from the chassis to which the slide bars are attached. The "Culloden Moor" photo of No.27 provides evidence for the tablet catcher and the position of the front vacuum pipe.

The shape of the fall plate enables the engine to negotiate curves without it fouling the tender upright stanchions. The cab interior is typical of a Jones engine, details owe much to the cab of the Big Goods in the Transport Museum in Glasgow. On the left hand cab side sheet can be seen the handle for the tablet catcher. Backhead fittings are modified LGM and 62C castings, the reverser is of my own devising. 

Brass rivets are soldered into holes drilled in the outer frames and filed flush inside so as not to foul the chassis assembly when this is removed. 

Self-contained sprung buffers add a further challenge to the model maker; the buffer beam is mounted on the ends of the frames which protrude beyond the smoke box and cylinders. 

The large rivetted balance weights are a prominent feature usually hidden by the splashers in photos of the prototype in conventional pose with coupling rods on show. Note the sanding mechanism on the sandbox top and the difficult to make trim to the splasher/sandbox assembly. 

A Tender in Search of a Loco.

My model of an early Highland Railway tender was built using as a starting point an etched sheet of nickle silver parts, provided by John Percival of Walsworth Models which, with some revision, will be issued under this label as a kit. The tender is much in evidence in early photos of Small and Medium Goods engines and of the Glenbarry class. These locomotive classes were all rebuilt and upgraded by Mr. Jones in the later years of the C19 and the tender similarly underwent changes, in particular the braking system was modernised; the most noticeable feature of the changes was the replacement of the old wooden brake blocks with metal brakes and my model includes the features of the rebuilt version of the tender. There are no kits in 7mm scale of any appropriate locomotive to run with this tender and I know of no plans to remedy this omission. For my part I have an "18" class, Small Goods, in rebuilt form, in the early stages of construction in my studio, this will be no. 27, built in 1863, which survived as the last of her class until 1923. 

The design of the tender is derived from earlier HR four-wheeled ones and owes a debt to LNWR practice. The buffers are from Slater's, revised and altered to self-contained ones. Note that the tank is the full-width of the tender, with platforms, which sit on the frames, front and rear. 

Most of the castings used to complete the model are from the Laurie Griffin range, Laurie produces a list of useful parts for a Small Goods building project. The white metal springs and tender-top tool boxes are my own castings. The water filler will be replaced by an LGM casting of a more appropriate Jones design. 

I used a drawing of a Jones "Loch" tender for the details of the brake cylinder, pull rods and linkages beneath the tender.   

Highland Railway Type B goods brake van.



Highland Railway Type B goods brake van d.25

I was aware that Walsworth Models had produced a kit for this attractive 6-wheel van and when I saw it on the Highland Railway stand at MRS earlier this year I thought it looked a quality product and I bought one. The kit proved to be well designed and etched in modeller friendly nickle silver, though rather let down by the quality of the brass castings.

I made several changes as I built the van, perhaps the most radical was altering the curve of the van roof which I thought was too flat. To do this I soldered a new correctly curved top onto the van ends, it wasn't a lot different but it made all the difference and I felt it looked better. However this small alteration had the unforeseen knock-on effect of having to remake the roof lookout windows, front and back, to match the curve of the roof and this was not a small job. I cut them to shape using a  pattern that I made from Peter Tatlow's very credible drawing on page 180 of his "Highland Railway Carriages and Wagons". I noticed that the windows on the drawing were a little different to those supplied in the kit so remaking them proved to be a definite improvement to the model.

I thought that the way the kit was designed left the edges of the windows very thin, about 0.25mm which is less than half an inch, so I soldered 0.45 n/s sheet behind all the window openings, lookout, doors and van ends, so the glazing would now be set in over an inch and give the van a more chunky feel. I also beefed up the rather slim footboards with a lamination of 0.25 strip and cut down the upper footboard to allow room for horse hooks on the solebars.

The axle boxes and springs were cast as one piece in brass, the use of this material being I suppose an attempt to upgrade the quality of the kit. However something had gone awry at the casting stage and the axle boxes were set at an awkward angle to the springs and there was nothing I could do to fix the error other than cut the offending axle box off and discard it. The springs by themselves were acceptable and I soldered them to the solebar without the brass axleboxes which I replaced with some nicely cast white metal ones I had in hand from a Lochgorm kit.

The couplings and safety chains that enliven the buffer beam I made myself; the safety chain hooks came from the spares box as those on the etched sheet were over-etched out of existence. The coupling hooks are sprung fairly stiffly, largely to facilitate removal when I paint the model. I don't want the springs to allow the coupling hooks much movement if any.

The improvements I made to the van are small though the effort in making them was huge, I think it was time well spent though you can judge for yourselves by clicking on the photos to enlarge them.   

The suspension system and brake gear.

The two near axles are mounted on a centrally pivoted bogie, the rear axle is screwed to the floor; a long 0.6mm rod runs the length of the floor and acts as a self centering spring on the bogie. Unseen are the screws that hold the superstructure to the underframe to allow access to the interior for glazing at a later stage.

So watch this space... I'll be working the van to a finish now; tomorrow the etch primer then the paint shop as I need to photograph the painted model in time to make the deadline for the Highland Railway Journal.