NOV 20 Bodmin

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Layout information:

Layout name: Bodmin
Scale/Gauge: 18.83mm P4
Size (to include any fiddle yards): 20ft x 4ft
Era/Region: GWR 1928
Layout type: Exhibition layout. Based on a prototype, end to end

The origins of The North London Group’s layout Bodmin go back to the late 1970s. Having built a model of an imaginary station on a non-existent main line (Heckmondwike, Yorkshire, on the Midland Railway's projected line from Dewsbury to Bradford) the Group then made a deliberate decision to construct an accurate scale model of an actual station in the form of a branch terminus as a contrast to the through main line format of the earlier layout. The prototype chosen was the Great Western terminus at Bodmin in Cornwall and having selected that station we were then faced with the problem of finding out what it really looked like 50 or more years previously, as we intended that our model should be as accurate as we could reasonably make it. This layout was first exhibited at the National Model Railway Exhibition Easter Show at Central Hall Westminster in 1980, some forty years ago!

There were two stations at Bodmin. The first of these was the terminus of the Bodmin and Wadebridge Railway, which was the earliest railway to be built in the West Country and eventually came under the ownership of the London and South Western Railway (LSWR). Half a century later the Great Western Railway (GWR) built their branch from Bodmin Road on the main line to a terminus at Bodmin itself in 1887. This station was later re-named Bodmin General by BR. A second line running from the terminus at Bodmin to join the old Bodmin and Wadebridge line at Boscarne Junction was opened in 1888. The GWR was granted running powers over the LSWR to Wadebridge and always treated the line as a single continuous branch, the terminus at Bodmin being the only intermediate station.

As you look at the layout, the line that singly curves away under the bridge is the junction to Boscarne Junction and Wadebridge. The model is a replica of the station and has been built to be as accurate as possible. It shows the terminus laid out as it existed between the two World Wars and we operate when the GWR Small Prairie 45xx class were new to the line in 1928.

This was an extremely busy branch line that kept three locomotives hard at work all day and required two sets of passenger coaches to run the numerous services. Over forty trains are shown daily in the timetable. Since many of these trains ran the entire length of the line this involved their reversal at Bodmin resulting in nearly sixty arrivals and departures every day. For this reason, the workings which are demonstrated on the layout represent only part of the day’s operations at the station.

A particular feature of the traffic on the branch was the carriage of china clay. Loaded clay trains were worked down the Wenford Bridge branch of the LSWR to Boscarne Junction and then worked over the GWR through Bodmin to Par or Fowey. These trains were balanced by workings of empty clay wagons being returned back up the line. Our layout demonstrates the workings of these clay trains.

The line had fearsome gradients and trains approaching Bodmin from both Bodmin Road and Boscarne Junction were faced with a climb of 1 in 40 or more. For this reason powerful small prairie tanks and pannier tanks were employed on the branch. We do, however, for exhibitions, use some modelling licence and run a few different locomotives in keeping with the area.

Construction of the Layout

The layout sits on a metal frame especially constructed for the layout. This is really perhaps over-engineered but it has certainly stood the test of time. From this frame, a gantry structure stretches over the layout. This gantry contains fluorescent lighting to ensure the layout is well lit. Baseboards are made of a chipboard surface with a 2in by 1in softwood frame. This was standard practice when the layout was built. Again these boards have stood the test of time.  The prototype station was built on the top of a hill which was levelled. This explains why the station and yard are in a cutting. Very considerable effort was put into the construction of the layout. This is seen in the layout pictures – everything had to be as accurate as possible. The station and yard are 13ft 6in long plus the fiddle yard. Total layout length is 20ft and width just under 4ft.

Track has been constructed to a gauge of 18.83mm to P4 standards. Code 75 rail is soldered to rivets in ply sleepers and then the rivets covered with 2 bolt whitemetal chairs. Because Bodmin is an accurate model of a real station the group took care to reproduce as closely as possible the design and construction of the pointwork.

The group decided that train control and signalling must be totally integrated. All switching of circuits is achieved through the signal lever frame. The idea is that the signalman has only to ‘think signals’ and the train driver then drives his train as authorised by the signals. The signal box lever frame is fully interlocked electrically. Communication between the signalman and the fiddle yard is by means of block instruments. There are two sets of instruments at the fiddle yard end representing Bodmin Road and Boscarne Junction.

All the buildings at 'Bodmin' were constructed of a very distinctive local stone with high relief and an interesting colouring of basic greenish grey with facets of rust colour. The model buildings were constructed from Plastikard applying individual stones of varying thickness to build up the walls. Then each stone was carved in situ to produce the chunky appearance of the roughly cut stone. Each stone was then individually painted in acrylics to carefully bring out the high points and relief in the stonework. The walls and bridges were all subtly weathered.

To assist the viewing public in understanding the train movements we have installed an LCD display. Synchronised with the timetable this enables the public to fully understand the operating timetable as each train move on the layout is displayed on the monitor screen.

The construction of many parts of the layout was covered many years ago in a series of articles in the old Model Railway Constructor from 1981 to 1984. The groups’ website gives dates and contents etc. of each article and old issues can usually be purchased from the Vintage Carriage Trust at Ingrow K&WVR (details on their website). Many modelling techniques and materials, now almost standard practice, were simply not available when the model was built. Despite this the layout presents a convincing portrayal that has stood the test of time exceptionally well.

Rolling Stock 

When modelling a specific prototype at a set time it is important to use prototypical locos and stock. As mentioned the model is set in 1928 after the 45xx class were transferred to the line. We have three of these two scratch-built before the Mitchell kit became available and one of the latter kits. All are compensated (as are all locos and stock) and use Portescap motors operated on DC using ECM Compspeed F controllers (with the feedback switched off). None have failed on us in 40 years.  The other stalwart of the line is a 57xx Pannier; a Mainline body re-worked to remove the post-war top feed on a scratch-built chassis.  This really ought to be a 2021 class Pannier but no accurate or original drawings survive for this class so we have been unable to build a fully accurate model. Other engines visiting the line during the timetable sequence are a Bulldog on a military special, and ex LSWR 02 tanks on through workings. In reality, it is most likely that all through traffic to the line would hand over to one of the 45xx’s but we allow these for variety. 

Information on this line in the inter-war period is still becoming available and we now know that although GWR coaches regularly travelled through to Wadebridge, the through workings were always handled by GW locos and SR locos would not be seen at Bodmin GWR. Furthermore, there was one daily working of an auto train up the branch with a 517 class (later 48xx) 0-4-2T in charge. This was as part of one of those long diagrams the GWR were so fond of, taking a Truro engine on several branches around Cornwall. The regular branch coaches used in 1928 were a brand new ‘B Set’ of a diagram not available in kit form so this was virtually scratch built around a basic skeleton of a body shell.

Wagon stock was also carefully researched. The GWR were not part of the ‘common user’ arrangement for cattle vans so all such traffic on the line, except any loaded in SR territory would be in GWR vehicles. However it is the china clay traffic that required the most research. This was the primary revenue source for the line and originated primarily at Wenford Bridge handing over to the GWR at Boscarne Junction. Post WW1 the industry was segmented and traffic was carried in a mix of private owner wagons. However, the English China Clay (ECC) company was formed in 1919, merging the major operators and absorbing the smaller companies. The newly formed business had operational priorities and private owner wagons were not re-liveried overnight (in fact we doubt if many were ever re-lettered), therefore in our period there would be a mix of pre-ECC wagons and some re-liveried and bought new in their livery.  It also appears that ECC moved away from using their own wagon fleet for china clay towards using dedicated GWR wagons built specifically for the purpose in the mid-1930s. The necessary wagons were scratch-built from Plastikard and transfers designed and produced by PC models specifically for the project. 

Operationally, because of the gradients of the line, loaded trains are limited in weight for the run from Boscarne Junction so many trains are split and made up at 'Bodmin' before onward movement. The track layout precludes movement down the Boscarne Branch from all but the branch platform road so again this makes complicated shunting of freight traffic necessary. All movements are controlled by the correct signals.

Although there are some ‘fixed sets’ of wagons coupled together by 3 link or Screw couplings, the ends of these rakes and all other stock is fitted with Alex Jackson (AJ) couplings which are operated by electro magnets. These require regular maintenance especially after stock is packed away between operating sessions but are virtually invisible. During the design phase, considerable thought was given as to the position of the uncoupling electro magnets in order to minimise unprototypical shunting back and forwards.

Operation

During an exhibition, the layout operates with four persons: a signalman operating the turnouts, interlocking and signals using the lever frame, two drivers and one fiddle yard operator. In addition, we have found that if we have someone at the end of the layout they can answer questions from the public and this allows for the operators to concentrate on their tasks and produce a professionally presented running layout. The schedule of train movements is fairly intensive and demands keen concentration by the operators. The operating sequence is based on the prototype Working Timetable with some additional ‘As required’ Q trains. A card system is used by the operators explaining what is required and a display informs the public of the time of day and the purpose of the move.  If I was to be critical perhaps the china clay traffic is a little heavy for 1928 as is the volume of special traffic, but these make the sequence more interesting for both the public and operators.

Lessons and Learnings

The layout was very well built by pioneers of P4 modelling. Maintenance and repairs have been minimal with the exception of the bracket signal where wear in the crank mechanism and the use of solenoids has become a problem. If doing it today we would use servos. When built and from our experiences of the then-current H&M point solenoids a slow action point motor was needed that reduced the amount of stress on the point blades which also moved realistically. This was achieved by a purpose-made mechanism incorporating a rotary motor based on a Tri-ang X04 motor and these are still in use. This would not be necessary today with Tortoises or Cobalts taking their place. Scenery is perhaps a little dated; bushes and trees being created out of foam cut up in a food blender (which promptly burnt out with the strain!) on either metal wire frames to create the trunks or wire wool for bushes that then rusted to dust. Grass was dyed lint glued face-down then ripped off which gives a good long grass effect but nowadays this would be mixed with static grass.  

The layout has passed the test of time with flying colours. It has not escaped some serious traumas over its 40 years, not the least of which was being deluged with water during a flash flood. Only the fiddle yard (the bottom sections when stored) was affected but this too survived with a little remedial work.

Basic lessons applicable to other layout projects are:

• Model something that is interesting to operate – there is far more chance of keeping your interest once the novelty of a new layout has gone, and develop a sequence or timetable to stretch the operating team.
• Prototype research is essential, work out how the layout will operate at an early stage and design appropriately.
• Baseboards need to be solid, well-aligned and square. Weight may be an issue but extra labour can sort this whereas a twisted board or bad joints will always result in poor running.
• If it is a club layout or one with several contributors, an owner or ‘gaffer’ and tough quality control is essential.
• Track needs to be well built and consistent, ‘Rivet & Ply’ track will last 50 years.
• Removable buildings (perhaps on a ‘basement’ set into the baseboards) are easier to repair when damage occurs.
• Get the correct locos and stock for the period and do not compromise on quality, scratch-build, or commission/design kits as necessary. This will differentiate your layout from others. Have spares.
• Do not wear out your team or over expose the layout by exhibiting the layout too much, but conversely take it out enough to keep it in use.
• Have somewhere to erect the layout as an entirety, practice is essential for a professional well run and reliable exhibition layout.

Mention must be made that a great many people were involved in the construction of Bodmin. Rather than miss anybody out no names have been mentioned. Unfortunately, some members are no longer with us. We trust that the layout remains a testimony to all who have been involved.

The 'Bodmin' layout is currently still on the exhibition circuit and recently exhibited at the Peterborough Show where it performed near flawlessly, a tribute to the skill, care and professionalism of the builders. Given the set-up time, realistically only two day shows are practicable. If you are interested in information on the North London Group, visit the website http://www.thenlg.org.uk/ alternatively, search engines seem to find it easily. 

Future projects

The North London Group is still active and meets every month just off the North Circular in Hendon.  New members and old friends are welcome (details are on the website). There are talks, film shows and modelling evenings with test tracks. However, we have suffered from our own success and several members have or are building their own layouts at home and therefore have little time to build another large club layout. The average age of the club members is also significantly higher than when 'Heckmondwike' and 'Bodmin' were built. The committee would certainly give their support and would dearly love for a group of members to propose a new club layout, backed with realistic plans including manpower to achieve this. 

Layout detail

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