Wednesday, 20 September 2017

LNWR Precursor Tank

LNWR Precursor Tank No.44 built 1909.  3' 3" bogie wheels, exterior sand boxes and Bowen-Cook buffers.

Pete's Precursor Tank was built with the aid of a Dragon Models set of etches and the brass castings that come with the kit though without any of the white metal fittings supplied which were replace by components sourced elsewhere or by scratch building, an example of this being the smokebox door. Construction is complete apart from the cab interior which awaits delivery of an LGM brass backhead casting. There has been a good deal of improvement made to the basic kit and additional work has been done using contemporary photographs as reference to ensure that all exterior detail is included in the model. The basic inside motion parts from the kit have been fitted, viewed from the angle of the photo the slide bars are just discernable in the gloom between the frames.

The engine is powered by an M1833 motor mounted in an ABCGears gearbox which is mounted upright on the rear driving axle. Current pick-up is through wires bearing on the treads of the drivers and the rear of the bogie wheels on one side of the engine; on the other side the wheels are shorted by means of a wire inset behind the spokes. Slaters' wheels are used throughout, the axles run in brass bearings which slide in slots in the robust 0.7mm side frames. There upright motor leaves no space in the boiler for a flywheel, however the running qualities of the model were more than acceptable when she ran on the Carlisle club layout last Saturday.

The cab front is double skinned which allows the inner skin to be removed at this stage for detailing. The backhead and all its attendant fittings and pipework will be attached to this inner skin, an arrangement that also facilitates glazing at a later stage. Similarly at this stage the rear bunker assembly can be removed to allow access to the cab though later this will be soldered into place; the roof will be soldered on too as this will add strength to the structure. Nevertheless the large cab side cut-outs, generously proportioned rear windows and hinged opening doors will ensure that the cab interior detail remains much in evidence.

Monday, 14 August 2017

HR Passenger Tank... construction complete.

HR46 Passenger Tank.

HR46 was built without the aid of a kit, though there are two kits available for the engine neither the current Lochgorm kit nor the old Shedmaster/LGM kit was used, past experience suggested that scratch building this particular prototype was the answer. The model does however rely on LGM  for the majority of the castings required. Construction is now complete and the model awaits the paint shop. HR46 will be finished in plain though dignified Drummond II unlined green livery, which I can manage to paint myself.

The mudguards are fastened to the frames which rather restricts the movement of the bogie so the engine will not negotiate tight curves. At CDOGG on Saturday on the club layout she did not run as well as I had hoped and at times I noticed that the bogie wheels were lifting slightly on curves, a sure sign that all was not well. Back at home in the studio I set about remedying this problem and to this end I filed away as much metal as possible inside of the bogie wheel wells and painted this area with epoxy glue so there could be no problem with shorting out with the result that the engine now negotiates the standard 6ft radius curves and pointwork of my home test track in exemplary fashion, whether the model will now run similarly on a club layout remains to be seen. At the moment the engine runs without a flywheel, which is a situation that I'd like to remedy and one that I'm looking into.

HR46. The cab doors open and close and are fastened shut with a sneck similar to the prototype.   

The Highland Railway Passenger Tank bears many resemblances to HR53 "Lybster" which I built previously and which the design of the Passenger Tank was based on. There are also many differences, the Passenger Tanks were by no means copies of their predecessor.

Cab interior detail.

Detail of door sneck on inside of door, also tablet catching apparatus attached to cab side sheet.

Detail of mudguards attached to the frames. Note also the tank balance-pipe behind the step and the brake transverse shaft attaching to the brake pull-rod behind the mudguard.

Tuesday, 4 July 2017

HR Passenger Tank backhead and cab interior.

HR46 Backhead complete.

I based the Drummond Passenger Tank backhead, to some extent, on that of the HR Loch class engines, for which a GA drawing exists. My presumption is that the Loch backhead followed standard Highland practice, so in taking this as my example I should be working on the right lines. I also took note of the backhead of the preserved Caledonian Railway 0-4-4T which my wife photographed from inside the cab. I thought that a Scottish engine, similar in many respects to the Passenger Tank, might afford some insight into the mysterious world of backheads c.1900.

The castings used in my reconstruction were mostly from LGM though I found the castings on offer from 62C Models useful too and of good quality, the injectors being from that source. Most of the castings I used were reduced in size and remodelled to some extent to suit the miniscule backhead. As an example, the bottom parts of the water gauge castings were cut off and replaced by a small tap, made from a hand rail knob and a length of fine wire, which reduced their length and enabled me to fit them above the shelf over the firedoor, which I reduced in width to leave room for the firedoor opening lever which is on the right, you can see its handle just below the water gauge.

On the left hand side of the spectacle plate can be seen the driver's brake valve which is connected to the injector on that side by a "flexible" connection. In reality the two are not connected at all, the flexible hose only butts against its continuation in the dark corner of the cab to enable the inner spectacle plate and backhead assembly to slide upwards for removal. There is an inner and outer spectacle plate, which much simplifies glazing at a later stage.
There is a metal plate on the cab floor under the firehole which is a detail I took from the preserved Caledonian engine, the floor planking, which is flush with the metal plate, is made of stripwood from a model ship kit.
The handle of the token exchange apparatus, which is out of sight outside the cab, protrudes into the cab behind the cab door stanchion.
The reversing lever, which attaches to the inside of the left hand inner tank, was a mini construction project in its own right. The tanks flank the backhead on either side of the cab and detract from the already restricted area of the cab, leaving little space in the model available for an engine crew ( see my previous post for a solution to the crew problem).

Tuesday, 6 June 2017

HR Passenger Tank... more progress.

HR 46 Superstructure practically complete.

The superstructure is almost complete and detail work is well under way. Castings for the tank top water fillers need a little modification and the dome needs rather more drastic surgery as I had to remodel the (wonky) safety valves which are mounted on top of them.
The smokebox door is made from 0.45mm nickle silver sheet cut to shape and persuaded into a convex shape in a doming block after which much filing produced the result above.

Cab interior partially finished

Some of the cab and backhead fittings are in place in this view, most of the castings have been sourced from LGM and need modifying for best effect. On the left cab side wall is the driver's brake valve that I cut down to size and at the same time moved the handle to the nearside, this apparatus will have a pipe that connects with the left hand injector which has yet to arrive though I've ordered what looks like an appropriate pair from 62C Models. Fastened to the the right of the spectacle plate is a lubricator again cut down from an LGM casting to a more reasonable size. The backhead water gauges look too big and need reducing in length, I may cut them down and add a small tap to the bottom which might leave room for me to fit a firebox door handle. The handle for the tablet catcher can be seen protruding into the cab between the stanchion and the inner side tank.

Opening door with cut-out to accommodate the tablet catcher mechanism. 

The hinged door has a sneck which fastens behind the front cab stanchion to keep the door closed. Inside the cab can be seen the coal hole door which opens by sliding upwards : beyond is the brake stanchion.

HR 46 Crew in action poses.

The driver is from the "Heroes of the Footplate" range which is now available from Chris Smith at "Invertrain". The fireman is my first essay in producing a shovelling figure, moulds for this are currently under development. Adding figures to the cab points up the very restricted space in which crews worked in these little engines.

Saturday, 13 May 2017

HR Passenger Tank Progress

Cab interior and backhead detail

My aim is to finish the sheet metal work first before adding the castings to the model. The brass backhead seen above is made from an etched fret supplied by Lochgorm Kits, it awaits fittings from LGM's 2-24 Drummond Backhead set. Though there is no drawing nor other direct evidence for the backhead fittings I believe they must have been fairly standard ones, much like those of the Loch class, for which there is a drawing, though adjusted to fit a smaller prototype. There is an inner front spectacle plate, to which the backhead is attached, which slides upwards so that this unit can be removed and worked on as a separate module. The circular brass window surrounds were etched to my own design.

HR 46 sheet metal work nearing completion.

The Highland built four of these little Passenger Tanks in 1905/6, based on Drummond's solitary HR53 of 1901 which was the subject of an earlier scratch building project on my Blog.

From the four possibilities I decided to model HR46 in original condition with the boiler bands on show rather than being covered by a saddle, which seems to have been added later across the side tanks of all these engines. Both front and rear spectacle plates are double to facilitate glazing.

Cab interior showing coal hole with sliding door.
You may notice that there's an "L" shaped angle piece covering the join between the boiler and the spectacle plate. This was made from "T" section brass, which can be persuaded to adopt a curved shape rather more easily than "L" section, which is quite intransigent. The rear flange is filed off the "T" section after it has been bent to shape to form the required "L" section.

The coal hole has a sliding door which adds interest to the interior of the cab, there will be much more detail in the cab before the model is finished and of course consideration is already being given to the poses and positions of the crew.

HR46 showing opening cab doors.

I've been poring over photos to try and understand the way that the sneck that holds the door shut from the inside works and I think I've got it; it's quite simple really and I'll see if I can replicate it in miniature tonight! There's a tablet catcher attached on the left hand side of the engine so the door will need a slot cutting in it to accommodate the operating mechanism of the apparatus which goes between the door stanchion and the tank side sheet.

Monday, 24 April 2017

A GSWR Timber Wagon

GSWR Timber Wagon

I built this little Scottish timber wagon recently from a Dragon Models Celtic Connections kit, it's now complete and awaiting paint and transfers. The wagon also needs a twin to make it viable as a load carrying vehicle. I thickened the wagon sides to a scale 3" and modified the brake gear on the etch to conform with that of a timber wagon rather than that of a pig iron wagon, which was the braking system on the etch. I also removed the raised lettering from the number and loading plates as I intend to design and print some improvements myself. The wagon floor is Plastikard planking mounted on the brass wagon bed. Length of the wagon over buffers is 120mm; weight is 175g. Though not an easy build, the wagon certainly looks the part and cries out for a mate to keep it company.

Wednesday, 29 March 2017

HR Passenger Tank

Highland Railway 0-4-4T Drummond Passenger Tank

I decided to build my latest project, a HR Passenger Tank, without the aid of a kit although I was aware when I commenced the project that there were two kits available for the engine... I didn't think that either would be of much help. Laurie Griffin's lost wax castings for this particular engine once again are proving to be indispensable however. I began construction at the end of February and these  pictures chart my progress. The engine is up and running and will have a test run under club conditions on the CDOGG layout at the weekend.

Much of the mechanism is revealed in this rear view.
Chassis and mechanism in close-up.

I've shorted out the wheels on the right hand side of the engine and rigged up wire pick-ups bearing on the top of the left hand side driving wheels, the pick-ups should disappear nicely into the front splashers and side tanks.
The n/s pick-ups are mounted on copper clad insulation board from where a wire leads back indirectly to the motor terminal. The motor gearbox is from ABCGears, it's a Mini 7S with an M1824 motor which will have to run without a flywheel as there is insufficient room for one. It's not the ideal motor-gearbox configuration, though as I had it in stock, it'll have to do.

Rear bogie top view, note guard irons tight behind rear wheels.

I added extensions to the LGM white metal bogie side casting for this engine from 0.4 n/s sheet, the rear guard irons are attached to these...mixed solder and glue construction. The centre hole is for the pivot which at the moment is un-sprung though I'm thinking about this. Wheels run in 1/8" bearings without compensation.

Rear bogie underside
The pick-up arrangement can be seen in this view of the bogie underside. A detachable wire screws to the CCIB and leads to the motor. The right hand side wheels are shorted out, one with a wire and the other experimentally with conductive silver paint, which seems to work well.