The Southwold locomotives were also quite individual; not just the original 1879 2-4-0 and 1893 2-4-2 Sharp Stewarts but the more powerful 0-6-2 Manning Wardle, Wenhaston, which joined the line in 1914 to meet an anticipated increased demand for goods traffic generated by the opening of the harbour branch (the traffic never materialised).
...... I promised myself that one day I would use this chassis as the basis for the construction of a loco based on Wenhaston. That time has now arrived! As with most things in life, though, now I've actually made the model, I now know how I should have gone about the job - if I knew then what I know now and all that. Hopefully, though, if you want to follow in my footsteps you might benefit from my mistakes and learning curve.
My first task was to strip down the Zillertalbahn loco to its bare chassis. The bodywork was easily detached from the chassis; firstly by unscrewing the chimney, taking out the front coupling, ..........
....... removing the screws which attached the cab to the chassis and detaching what I assume is the 'brass' safety valve from the front of the cab.
The cab could now be separated from the chassis.
To detach the front end of the loco body, two screws were removed from just in front of the cab and the body was then slid forward to detach the lug at the front.
After removing the Massoth DCC decoder which I had installed soon after acquiring the loco, I was then able to size-up the chassis.
The trailing bogie was removed by unscrewing the two screws on the retaining plate. The bogie was set aside to be used in the completed loco but the pivot arm will need to be reduced in length.
The cab footplate was then carefully excised from the main chassis with a razor saw, leaving me with the main chassis. The wheels are the correct size for a 15mm:1ft scale model but, although the axle centres are about right on the leading and centre driving wheels, the wheel spacing is too narrow for the trailing driving wheels. However, as correcting this would require a wholesale rebuild of the chassis, I decided this was a detail which I could live with.
I next stripped down the chassis to remove any unnecessary wiring for the track pick-up system. On this U-class, pick-up was via carbon rods bearing on the backs of the driving wheels. An arrangement of brass contact strips inside the frames carries the current from the back of the pick-ups to a couple of bus-bars which run the length of the chassis.
All this paraphernalia was removed .......
..... and the chassis loosely reassembled for painting, later.
Having measured-up the chassis and compared it with the plans for Wenhaston found in the Middleton Press Branchline to Southwold (Mitchell & Smith, 1984) and in the March 1987 edition of Model Railway Constructor, I marked-out and shaped the rear footplate from a piece of 2mm thick (80 thou) plasticard.
I next cut-out the sides for the water tanks from 2mm plasticard.
To these were glued the ends, top and bottom of the tanks which were cut from a mix of 2mm and 1.5mm thick (60thou) plasticard - largely because I was constructing this model whilst on holiday abroad and had brought only a limited supply of 2mm plasticard with me.
I removed a section from the lower part of the inside edge of the tanks in anticipation of filling these with lead weights.
The curved edge of the tanks were built-up from scraps of plasticard and filler, sanded down with a needle file and sandpaper.
This will be fine-tuned later after a couple of coats of primer. The tanks were then glued to the footplate.
After hunting around the bits-drawer and garage at home for some suitably sized bits of cylindrical plastic, I found the diameter of a tube of silicon sealant to be spot-on for the smokebox. A piece of this was then cut to size .......
....... and glued between two pieces of 1.5mm thick plasticard, suitably shaped.After trying a few different types of adhesives, I opted for clear UHU to fix these parts together. The sealant tube is made from some sort of oily plastic which does not seem to accept most glues - presumably this is why this plastic is used for packaging sealants.
As with the curved section of the sidetanks, the concave curve where the smokebox meets the footplate was fashioned from offcuts of plasticard and dollops of filler, filed and sanded to shape.
The front and rear of the cab were then cut from 1.5mm plasticard.
The sides were also cut out (from 2mm thick plasticard for rigidity), and the cab was then attached to the footplate.
To provide additional support for the rear of the bunker, an additional piece of 2mm plasticard was shaped and glued to the centre of the cab rear.
The front half of the firebox was tackled next. A couple of pieces of 2mm thick plasticard were shaped for the front and rear of the firebox .......
and a piece of 1mm thick plasticard glued over it. This assembly was then glued into place between the side tanks.
I was not too happy with how this looked and so another piece of 1mm plasticard was glued over the top and the space left between the two layers was filled, filed and sanded. As I was working from a drawing and a couple of indistinct photos, I decided to use modellers' licence over the exact profile of the firebox. With the restricted room inside the body, I needed as much additional height as I could manage. Yet another compromise.
The leading edge was then rounded off with a needle file and smoothed off with fine sandpaper. The rear half of the firebox was constructed next in a similar way. I decided to make this slightly deeper than the prototype to accommodate the radio control receiver and motor controller.
This was then glued into place in the cab.
I like the roofs of my locos to be removable to facilitate detailing and painting. A framework of 2mm plasticard was made to be a snug fit inside the top of the cab. I tend to glue items like this together with Superglue as it dries more quickly than solvent adhesives which means I can more readily move on to the next stage.
To this was attached a piece of 1mm plasticard (held in place with clothes pegs until the glue set).
The roof was then test-fitted......
Next,the sandboxes were constructed. The sides were constructed first from 1.5mm plasticard and then, when the glue had set, oversized tops and bottoms were added.
Once the glue had set, the tops and bottoms were trimmed to size and the whole thing lightly sanded. I've found from experience that this is a more accurate way of ensuring the tops and bottoms actually fit the sides. The same method was used for the toolbox which was attached to the footplate beside the smokebox. One source suggests that the toolbox was needed because when the loco was delivered it was found to be underweight over the leading driving wheels.
The outer frame of the toolbox was then added from 4.5mm wide strips of 1mm thick plasticard.
The inside section of the coal bunker was tackled next. Having no details of its appearance, I assumed it would be similar to other tank locos. A piece of 2mm thick plasticard was cut to size and then a 14mm x 14mm hatch was cut into the middle of the bottom edge. Two strips of 1mm square plasticard were then glued vertically either side of the hatch and a 16mm square hatch cover was cut from 1mm plasticard.
Two 2mm x 1mm strips of plasticard were then glued on top of the strips to provide a grooved slideway for the hatch cover.......
....... which was slotted in to be allowed to slide up and down.
On returning from holiday, I had a slight change of plan. I removed the rear of the cab so I could add some detail to the backhead of the firebox. A set of whitemetal detailing parts was obtained from GRS (Garden Railway Specialists) and these were affixed roughly where I felt they would have been on the original loco.
Next, the chimney, tank fillers, safety valves and whistle were attached to the top of the smokebox and firebox. These again were provided by GRS as whitemetal castings. I was stumped when it came to finding a dome, however. Nothing which GRS had available was suitable, but a trip to the local supermarket resulted in the purchase of a bottle of after-sun cream with an interesting-looking domed cap.
This proved to be more or less the right size - but actually would have been entirely accurate had I been constructing the model in 16mm scale(!). The cap was shaped to fit the boiler, glued on and liberal amounts of filler used to merge the dome into the curve of the boiler. The was smoothed down with various needle files and increasingly smoother grades of emery paper.
The mouldings provided by GRS for the safety valves seemed to be missing a couple of vital components - the coiled spring and a the actuating lever. The spring was fashioned from a coil of multi-core solder ......
... while the lever was cut from a sheet of brass. The whole assembly was fixed atop the firebox and filler applied and smoothed to fill the inevitable gaps.
Before moving to the next stage, the battery was fitted into the body. Because the motor housing is quite prominent on the chassis, there was very little space in which to fit the battery pack. I opted for a 12v 6800mAh Lithium-ion battery which can be obtained from China via a well-known online auction site.
The pack was too long to fit into the available space and so the outer casing was removed, as was the integral switch and wiring loom.
The battery pack could then be slipped in towards the front of the side tanks. At the same time a quantity of .22 calibre air rifle slugs were poured into the back of the smokebox and fixed in place with liberal amounts of Superglue - I know from experience that my locos benefit from as much additional weight as I can squeeze in.
The battery was then shrouded in masking tape and the body given a couple of coats of grey Halfords primer from a rattle-can aerosol.
The interior of the cab was then painted in acrylics.
..... and ½" fibre washers were glued into the spectacle openings.
The rear of the cab was also primed and fitted-out with washers, before being re-glued on to the body.
Pieces of lead, cut from a length of roof flashing were glued into the bunker to provide some additional weight.
The trailing bogie was tackled next. Firstly,a new pivot bracket was attached to the rear of the chassis block and drilled to accept the pivot. As the chassis splits down its middle, this plate was glued only to one half of the chassis with Superglue which seems to be the only adhesive which LGB plastic will accept.
A corresponding hole was drilled in the end of the pivot arm for the trailing bogie ..........
.... and a 2mm bolt was passed through and held in place with a double lock-nut to allow the pivot to swivel without becoming unscrewed.
A cradle for the axle boxes (from GRS) was constructed from 2mm plasticard .......
After testing and finding the bogie had a tendency to derail, a support for the pivot spring-plate rescued from the original U-class model was then attached above the pivot. The pivot arm was also shortened to bring the trailing bogie closer to the main chassis. This was another compromise - the trailing bogie should be further forward but I was concerned that bringing any closer to the main chassis would lead to problems over some of the tight curves and the LGB R1 points which I have on my railway.
At this stage, I decided to install the rest of the electrics. I was using a Mac Five motor controller from Brian Jones and a transmitter / receiver set which I had acquired cheaply from the ubiquitous online auction site ..............
The wiring circuit for this set-up is fairly straightforward.
Brian Jones or from Maplin - Order Code: AK08J) is quite important, given the propensity Lithium-ion batteries have for catching fire if short-circuited it's a wise precaution. The 2.5mm DC charge-socket (Maplin order code - JK10L) was wired-up first, followed by the switch (Maplin order code FH36P), with heat-shrink insulation (Maplin order code - N03FT) covering all the connections as once the wiring is stowed away it will be fairly inaccessible.
Then all the components were packed into the various nooks and crannies which had been left for them and the remaining space in the side tanks was filled with chunks of lead hacked off the weights in the original loco.
After some initial test running, I tackled the cab handrails. The upper supports were fashioned from 1mm thick brass sheet and the handrails themselves from 1.5OD mm brass tubing.
The handrail assemblies were then glued to the tops of the cab sides with the bottoms of the handrails slotted into appropriate holes in the footplate.
And a little more test-running was then called-for.
To fill the void underneath the cab, two sideframe sections were fashioned from 2mm thick plasticard.
These were then attached beneath the cab .......
.... and a piece of lead weight from the original U-Class loco was glued between them......
..... while another piece was cut and inserted into the chassis between the cylinders to counterbalance the weights fore and aft.
Two lengths of 1.5mm OD brass tube were shaped and inserted into the ends from cheap retractable ballpoint pens and glued beneath the sandboxes. The buffer beams were also cut out and rivets applied (from Cambrian Models - Order code NA7).
After adding some cosmetic filling and rubbing-down with fine emery, the interior of the cab was masked off ........
...... before a coat of Halford's Rover Brookland's Green was applied from a rattle-can aerosol. Once this coat had hardened off, it was rubbed-down before another final coat was applied. The buffer beams were then picked out in red Plasticote paint and the subframes were painted with black acrylics. The top rim of the chimney and the spectacle frames were painted with Plasticote brass paint. Crushed coal was glued into the coal bunker with exterior PVA.
And some more test-running was carried out until the battery became exhausted.
I hit a small problem when recharging the battery until I realised that the 1.6 amp auto-reset fuse was preventing me from recharging the battery at 2 amps (obvious really) and so the charger was reset to charge at 1.2 amps.
I now turned my attention to the smokebox. First of all it was painted matt black - black acrylic to which some talcum powder had been added. I then drilled three 1.5mm holes to take the handrail knobs - cast in whitemetal and available from GRS.
A handrail knob was threaded on to a 60mm length of 1.5mm OD brass tube which was then shaped to fit the top of the smokebox.
The handrail was then fitted to the top of the smokebox with epoxy. At the same time, the smokebox door handle (rescued from the U-class loco) was glued on to the smokebox door.
Four guides and two angles were fashioned from 1mm dia brass rod. The angles were soldered to the end of a 100mm length of 1mm rod and the guides were fixed into holes drilled near the rear edge of the side tanks.
The long rod was then threaded through and on into the front of the cab. The angle was slotted into the back of the sandbox and everything was fixed in place with Superglue.
The nameplates were then glued on to the sides of the tanks with epoxy.
The loco was then test-run again.
After putting the loco into service, I became disappointed in her performance. She seemed to struggle up some slopes and run away down others. At first I assumed this was a feature of battery control which, unlike DCC control, does not include load compensation for the motor. However, after some enquiries on the G Scale Central forum and some close scrutiny of the loco under load, I realised the problem was being caused by the bracket supporting the valve gear rubbing on the track.
I realised that on the original U-class loco, the upper end of the bracket hooked into a part of the footplate which I had removed. I decided that I needed to replicate this missing piece of superstructure. Casting around my various odds and ends, I happened upon a length of 6mm wide and 1.5mm thick brass strip. This was bent to fit over the motor block.
I then filed a slot into each end to accommodate the upper end of the valve gear bracket and then a short piece of 0.5mm diameter brass rod was soldered to the end of the new bracket.
The top of the valve gear bracket was then slotted into new bracket and the brass rod bent round it.
Two holes were drilled into the upper part of the bracket and a couple of self tapper screws inserted to hold it in place.
Since writing the above, the loco has been fitted with a driver made from Fimo and a brake standard in the cab.
I am still in two minds as to whether to line the loco in gold as all with other locos in the fleet. Somehow, leaving her in an unlined state gives her an even closer relationship with Wenhaston, the Southwold loco on which my model is based.
My researches have shown that although Wenhaston was lined when delivered from Manning Wardles, she was then painted plain dark green, which she retained until she was scrapped - though in her latter years her paint faded and her underlying original livery began to show through:
|Wenhaston towards the end of her working life - Source: Southwold Railway Trust|
In the meantime, a sound card has been added which includes a coasting effect varying the volume and tone dependent on whether the loco is accelerating or decelerating - see How I added a steam sound card to a battery loco