Graham gives a masterclass in creating a truly up-to-date modern image set!

MY LAYOUT, NETHERWOOD SIDINGS, is set between 1977 and 1981 in the Sheffield area. At shows we run firstgeneration DMUs of classes 114 and 123, but I thought it would be interesting to have a model of one of the units that operate the line today. It would also make an interesting modelling challenge, to see how different it is, building a truly up to date unit. The class 195 DMUs recently built for Northern Rail by CAF make a striking model very different from anything else.

The first challenge with any modern multiple unit (and I include anything post 1970 here as 'modern'), is getting hold of information. There are no published plan books or drawings. However, train operators and manufacturers are keen to publicise their new stock on their websites. An internet search turned up a pdf document published by Northern just before the trains entered service. This contained a line drawing with some key dimensions.

I used this, along with some side-on photos found on the internet, to draw side and end elevations in AutocadLT. I should add that this project was being done during lockdown 2, so I could not go out and photograph the real thing. As soon as the lockdown eased, I went to Sheffield station and took lots of photos of 195 018. I also made as many measurements as possible of key dimensions, like window and door sizes. The unit was stabled in a curved platform which enabled me to stand directly in front of it and get a good square-on photo of the front. This was then imported to AutocadLT, scaled to suit, and traced. This gave me the body cross-section profile.

Before getting too far into the project, I thought it wise to test the practicality of the build by making a small section of body side. The material I used for most of the model was Slater’s Plastikard of 0.040 and 0.060 inch thickness. The real vehicles are 24m long, which is over 500mm in 7mm scale, longer than a standard sheet; but Slaters sell larger sheets from the factory, so I bought a couple of these. I used 0.040in for the body sides and roof and used the 0.060in where I needed more rigidity, in the ends and for ribs supporting the roof.

The first stage of making a body side was to shape a piece of hardwood to the correct profile to use as a former. I printed the cross-section to scale and stuck this to a piece of Plastikard, then cutting it out to make a template for the body profile. I used this to check the shape of the wooden former. The plastic body side was heated and shaped over this former. The short test section went quite well but I had some trouble with the whole bodyside as it was difficult to evenly heat up a piece of plastic 550mm long. The Guild Forum was useful here, as a couple of members suggested wrapping the side and former in elasticated bandage before heating it. I did this, heating it in a fan oven set to 100°C. This worked very well.

The next task was cutting out the windows. I cut the windows on the test section by hand but decided a more accurate method was needed for the production sides. As I have a vertical mill with digital read out, it seemed a good idea to use it. I clamped the side, still on the wooden former, to the table and used a milling cutter to cut out the openings. I read the coordinates of the corners of the windows off the CAD drawing, divided by 43.5 then moved the cutter to each point. Machining plastic can be problematic as the plastic can melt, but I found that using a new cutter, low spindle speed and high feed rate worked well. Clearing up the statically charged plastic swarf was another matter though!

The sides were strengthened by cementing on another layer of Plastikard on the lower part of the inside. This was arranged so its top edge was at the right level to support the seats.

The windows on the prototype are flush with the outside of the body and glued into a recess. This can be seen from the outside as a black border round the window. I modelled this by gluing strips of plastic on the inside, overlapping the window opening by 1mm. This recess was then painted black and the glazing glued in with Deluxe Materials R/C modellers' canopy glue. The door windows were done in the same way, but had bigger corner radii, so an inner door was made from 0.030in plastic, with curved corners filed to final shape once glued in place. The doors themselves are part of the sides, with no scribed line to separate them. The rubber edges were represented by simply drawing lines on the painted side with a fine point indelible pen.

The cabs were always going to be a tricky part of the build, so I built them separately from the rest of the body then attached them when finished. I started with short sections of shaped Plastikard, which were formed to the side profile. These were doubled up in thickness at the front and glued to a bulkhead made from 0.060in Plastikard and shaped to the body profile. The rough shape of the front (looking from one side) was cut and the cut edges strengthened with a strip of 0.060in Plastikard cut to the width of the uprights each side of the windscreen. Horizontal pieces of 0.060in were then fitted at top of windscreen level, just below the driver's desk and at floor level. Using the drawing I had prepared, I cut a template for the headlight covers and used this when cutting the headlight openings in the front.

Once satisfied with the general shape and dimensions (checked by laying it on the drawing), I sanded the taper in the sides. It needed a couple of cycles of filling, shaping and sanding to get a realistic shape. The cab roof was made by building up the profile from filler and smoothing it to shape, using the body profile template to check as I went. The headlight in the cab roof has a curved glazed front and this was cut from an empty drink bottle.

I made the chassis two different ways; I first tried folding up a brass sheet to make a U shape but found it difficult to fold such a long section accurately. I used this chassis for the non-powered car. I then tried fabricating a chassis by soldering brass angle to a flat brass sheet. This was better, but still not perfect as it was difficult to get enough heat in to solder it. As it was heavier, I used this chassis for the powered car. The front of the unit is swept up from the solebar to the area where the anti climbers are.

Anti-climbers are a feature of modern stock and are serrated plates fitted where normal buffers would be located. They are designed to engage with one another in a collision and prevent over riding of the vehicles. They can be seen on the inner ends of the units but are covered by a grey GRP cover on the cab ends. This swept up feature was represented by having a section of floor under the cab set lower than the main floor, but curving up to the front. A section was cut out of this to provide the coupler recess and this section was made with a U shape, bent from brass sheet. The anti-climber covers were built up from Plastikard and filler and sanded to shape, referring to photos and the drawing. Another feature not seen on first generation DMUs is the obstacle deflector (often incorrectly called an air dam). I shaped this from thin brass with bracings from heavier brass and brass tube. This was soldered beneath the cab floor.

The body shells were assembled by attaching the sides to bulkheads cut to the body profile from 0.060in Plastikard. At each side of the door positions the sides were strengthened with 6mm square plastic rod also shaped to the body side profile. These represent the door pillars on the prototype. More thick Plastikard was added across the top of the doors to represent the covers to the door operating gear. These pieces also provided additional support for the roof. The roof was formed from 0.040in Plastikard in the same way as the sides. There are two profiled sections to each roof and two flat sections where the air conditioning units are located. I attached black Plastikard 'floor' sections between the doors, to make the body shells into a tube structure for strength. Once the cabs were attached, the shells were given a couple of coats of Halfords white acrylic primer and sanded/filled where necessary.

The air conditioning units were built as Plastikard boxes. The cab air conditioning unit has a vent at the top and one at the side, both covered by metal grilles. The side one was made by scribing clear plastic and wiping silver paint into it, but the one on the top which covers a fan was not convincing when done this way. This one was made from 0.33mm nickel silver wire. A template was made on a piece of plywood with holes drilled round the outside of the fan. U shaped pieces of wire were held in these holes. The pieces were soldered together, then a length of wire was wound round on top, soldering it to the bars as I went. The units were finished off with pipes and wires formed from plastic rod.

When I started this project, I didn't plan to include an interior. However, as it progressed it became clear that the absence of an interior would be very noticeable through the large side windows. The seats in the real units are plastic shells with thin (uncomfortably thin!) covering on them. I recreated this by cutting the seat shells from 0.030in black Plastikard. These were made as pairs of seats. Each pair was shaped by bending it after heating it over a hot soldering iron. The seat coverings were cut from pale blue felt material stuck to the seat shell with double sided tape. The pattern on the seats was represented by dabbing with dark blue paint. The draught screens by the doors were made from Plastikard, clear and opaque pieces, with a length of nickel silver wire for the handrail.

To the side of the doors there are panels with door controls, emergency alarm call point, etc on them. The easiest way to represent these was to cut an image of them from a photo, print it onto transfer paper and attach it to the door pillar. It was quite tricky applying transfers to the interior of the body.

The inter-car coupling was another challenge. On the real unit the gangway looks like a single unit pivoted at each end, so this is what I did too. I formed a piece of corrugated Plastikard round a Plastikard frame to make a 'tunnel'. The floor of this tunnel was extended beyond the ends to give tabs that could be pivoted from the vehicle ends. Before going too far I tested that this would work on my layout. On reverse curves, 24m vehicles were always going to be a challenge, and so it proved. However, I found the unit would go round the layout and into the outer fiddle yard road, so I settled on that as a compromise. The ends of each car were cut to clear the gangway unit at maximum travel. In order to maintain the body shape there is also a solid inner end on each vehicle which is set back from the real end.

The bogies on the class 195 are inside-framed with lots of detail visible. I just modelled the most visible parts of this detail. The basic structure consists of two brass frames with brass block spacers held together with M2 countersunk screws. A flat plate is bolted to this with spacers to a similar flat plate on which the Canon can motor is bolted. A train of nylon spur gears runs in the gap between these plates with nylon bevel gears driving the axles. The wheels are unlike any available from the trade (and we were in lockdown anyway, so supplies were patchy), so I turned my own from steel bar to the Guild finescale profile. The outer faces of the wheels were shaped to represent the brake discs and the disc mounting bolt holes represented by spot drilling dimples into the wheel face. I used a rotary table to ensure these dimples were regularly spaced.

The detail on the bogies was built up from brass sheet, starting with the outriggers which support the suspension air bags. Once these were soldered on, I soldered pieces of thicker brass to the frames, to act as outriggers to support the brake callipers. The caliper units themselves were fretted out of thin brass sheet using a picture on the Knorr-Bremse website as a guide. The brake pads were cut from thin fibreglass PCB material, in case they touched the wheels and caused a short. The various dampers were made from brass tube and wire, but the yaw damper brackets were a problem (they have proved to be a problem on the real units too!). If attached to the body, as prototypical, the bogies of the model would not be able to rotate sufficiently. I therefore attached them to a plate on top of the bogie which rotates with the bogie. This plate is hidden behind the solebar. This also simplified the attachment of the roll and pitch dampers, all of which were made from various sizes of brass wire. The electrical pickup is on the 'American' system, with one bogie picking up from each rail. The non-powered car has no pickups.

The unit was painted with acrylic paints, using Halfords gloss white as the base colour.

The blue was brushed on using Vallejo Model Color paint (a mix of medium blue and intense blue). The grey roof and underframe was Vallejo medium grey. Most of the marking on the sides, such as 'Northern' and 'n' lettering, door markings, door release panels, etc., were made as transfers using photos of the real units as the artwork, tweaking where necessary using an image editing program. The body shells were given a few light coats of gloss varnish from an aerosol can, to seal the transfers.

On the real units there are dot matrix destination displays at each end and on each side of each car. I thought it would be an interesting challenge to fit working displays to the model. I used the smallest OLED displays I could find. I used graphic displays, as these gave more flexibility than text displays. The displays are driven by a 4-wire I2C bus, which runs from each cab to a computer board mounted under the powered car. There are also LED lights fitted along the ceiling of each car and in the cabs. All these lights are controlled by the computer board. This is a small microcontroller board known as an STM32. The program it runs reads the DCC signals on the track (using the NMRADCC Arduino library), determines which function buttons have been pressed, and switches the lights on or off as appropriate. For the destination displays, five destinations and 'not in service' have been programmed in and are selected by functions F4-F9. All this electronics does mean a lot of wires, and the inter-car connection is made by a 15-way D connector mounted inside the gangway between the cars. The traction control, and headlights, are done by an ESU LokPilot decoder

The finished unit certainly looks very different to my BR blue stock, and with the latest Northern Rail lettering and passengers wearing face masks, it is bang up to date.

Building it was quite different to my other models, particularly the cabs, as the windscreen reveals quite a lot of the cab interior. The flush glazed windows proved easier to build than on a first generation DMU. Similarly, the doors were quite straightforward, being just painted on. I did consider making a transfer for the whole of the door detail, but didn't go forward with this as I thought it would be difficult to colour match the printed door colour to the painted body side. One obvious difference to earlier stock is the livery – with BR blue stock, there is just the numbering and OLE warning signs. The 195 has a plethora of lettering, signs and symbols all over it. Fortunately, waterslide transfers are now easy to make with a computer printer. As a lockdown project, the time taken to build it was not a great concern, but it did take up six months of modelling time, which is quite a bit longer than I would normally spend on a 2-car unit. It was an interesting challenge, and one I would do again – the other service we run on my layout is Trans Pennine, so a 68 and Mk5 coaches would make a good project.