SAR "Commercial Street" - LMS "Wellingford & Bakewell Bridge Railway" - GWR "Porthminster" - Port Dock Station

Thursday, 20 June 2013

Porthminster Modules & Track

Construction of the modules proved to be more difficult than first thought due to the shapes needed to produce each module. There are so few straight lines in the plan that each module is different from the next physically in shape and depth.  There seemed like mountains of scrap timber left over due to the immense number of jigsaw cuts needed to produce the curved track beds and profile boards.  The first module constructed was the end module with the tin mine.  The two bridge modules were made up without the semi-hidden main line storage loops. Then the two Penwith Station modules were constructed keeping in mind that there was no room for slip ups in their dimensions so that when the last module was constructed that they all meet up without alignment issues.
The layout viewed from the branch junction end. All track work complete.
Operators will be in the central isle while public viewing around the outside.
Once the modules were set up and all clamped together, all the joins were drilled for two alignment dowels and two (3/8”W X 2 ½”) bolts with wing nuts. Each module has its own fold down legs with gas struts attached. These will hold the legs in place during assembly/disassembly allowing a speedy set up and pull down time. The main timber frame of each module comprises mainly Pine of 63 X 19mm cross section. All the baseboard tops and track beds are 6mm MDF. All the profile boards are 3mm MDF. The last part of the plan was to arrange and construct the semi-hidden storage loop timberwork behind the view block of the bridge modules. Some very tricky woodwork was needed here.
Looking along the backdrop with the viaduct to the left
(front of the layout) and the semi-hidden passing
loops for the two main lines.
The reason this layout is being built is due to the acquisition of that beautiful Brunel Viaduct. So it was carefully removed from the cut out layout pieces in which it was built on and arranged on the new modules. On the original layout the last owner had built the viaduct as one piece, but was thankfully only resting, not glued to the piers. The viaduct was trimmed to 3m from the original 4.5m. Some juggling of the deck was needed to allow future cuts to be made at the joins of the modules so that none of the fans would be in the way.   Each pier was trimmed to length so the timber fans and deck would be level. The deck was then aligned to the track plan and clamped. All the piers (cast from plaster with a timber core) were then glued and screwed from underneath to ensure a solid foundation to finally glue the deck to. Once all the glue had dried, cuts were gingerly made at the joins of the modules – a tedious task keeping in mind I didn't want to destroy any of the timber guard railings along the deck. Though the viaduct was laid with code 100 track, ballasted and glued in the 1960s, it was in remarkably good condition so I consciously decided to leave it unmolested and marry it to my code 70 Peco track at either end.
The The Class B Brunel Viaduct with Class A stylised piers originally
built by Kev Loughhead in 1969 for his Moping Branch Railway 

Click on the photos to enlarge

Always seeking a challenge, the tracklaying was begun with difficult areas tackled first. The scissors situated in the middle of Penwith Station yard was made up using four Peco medium radius points and the short crossing. Careful trimming allowed for all the components to be superglued together producing a very unique piece pleasing to the eye.
The five Peco track components needed to produce the scissors for Penwith 

As I was nearing completion of the track work for the branchline junction in Penwith I had no choice but to hand make the double curve crossing. To get a smooth transition of curves and to get the curved points to fit, the crossing needed the curve of the branchline to start on the diamond rather than after it. I was quite happy with the result and running different types of vehicles through the crossing showed up a few adjustments needed for smooth running.
The double curved diamond crossing under construction.
The crossing in place.