Graham Clark

The Heljan air-braked wagons were a very welcome addition to the range of RTR models now available in O. They are accurate models and are superb runners. However, there are only two types of wagon to choose from, the VAA van and the OAA timber-sided open. I thought it was a shame that Heljan only made these two wagons and didn't make the chassis available as a spare part for us to put other bodies on. I need a few SPA steel plate wagons for my layout and thought I could put an SPA body on a Heljan chassis. I was therefore delighted to see Heljan selling second grade wagons at knock down prices at Telford and I bought a VAA van to convert. Just in case I became tempted to leave it as it was, I bought the EWS liveried version as that would force me to do something with it.

On getting the model home I stripped it down and compared the chassis to drawings and photos of the SPA wagon. That is when I discovered that the chassis that Heljan modelled was not right for an SPA wagon (apart from the two prototypes, which apparently never entered revenue service). The solebars of the Heljan chassis are shallower over the W-irons and deeper in the centre of the wagon, whereas the SPA has a constant depth throughout. While it would be possible to cut the Heljan solebars down, there wouldn't be much of the Heljan moulding left. So I looked at what else I could make from the VAA van. The VBA and VCA designs are similar, but according to David Larkin's book, they didn't operate very widely. The much more common van was the VDA. I therefore decided to convert it to a VDA.

The main differences between a VAA and VDA are that the body of the VDA has four doors rather than two, has the end bracing on the outside as opposed to inside and has a slightly different solebar shape. All these differences are pretty straightforward to make to the Heljan model.

Start by stripping the model down. The body is held on by two screws up through the floor and once these are removed, it can be prised off. I found it easiest to remove the couplings first. The chassis can then be stripped down by prising off the solebar mouldings, which releases the wheels. On my 'second grade' model one of the wheel discs was loose and it was easy to glue that back on at this stage.

The solebars were modified by cutting into the ends to make the depth constant from the ends to the inner edge of the W-iron. The flange of the solebar was then carved off from the centre section between the W-irons and a piece of 0.040in Plastikard glued on to make the solebar deeper. The Heljan plastic is quite hard but can be glued with MEK. I then added new lower flanges to the solebars using 0.015in Plastikard strip. Photo 2 shows a modified solebar.

The body conversion entails changing the door arrangement and adding end bracing. I started with the body sides. I filled in the old door handle holes with filler and cut new ones by drilling in each corner and cutting out with a piercing saw, finishing with files. The Heljan plastic is quite thick, but seems to be normal polystyrene. Rectangles of 0.040in Plastikard were glued into the holes, flush at the back, leaving an indent at the front. The handle mechanisms fit in these recesses and were made up from pieces of Microstrip and Microrod, using photos as a reference. The areas of missing side ribbing where the old handles had been removed were then made up with thin Microrod glued on. I reduced this to a semi-circular section first, by scraping it with a scalpel.

The doors won't be an accurate representation of a VDA as the vertical lines of rivets are still in the VAA position, but I could live with this. The final alteration to the sides was to add two vertical lengths of Microstrip each side of the centre position to represent the door edges. I first scraped the area where these are stuck flat using the edge of a small file before solvent welding them on. One of the pictures shows the van side before repainting.

Modifications to the chassis in Plastikard

The body before repainting

The hardest part of the alterations to the ends was to remove the Heljan paint. This needs to be done as it is necessary to stick the new Plastikard bracing on securely by solvent welding it to the Heljan plastic. Soaking the end of the wagon in brake fluid overnight helped, but it was still necessary to scrape and sand the end to get the paint off. The buffer beams unclip from the ends and need to be cut down in depth and refaxed so that the front face is flush with the end. While they are off the wagon pare off the rivet detail as the vertical bracing will need to be glued here. Cut off the centre section of the lip on the bottom of the van end and reduce the thickness of the outer sections which remain, so that the buffer beam sits flush with the end. It can now be glued back on.

The vertical ribbing on the ends was made from 15 thou Plastikard strip flanges glued to the wagon end. The webs were then glued on to these and the horizontal bracing added. Finally the outer flanges of the verticals was attached (there are no outer flanges on the horizontal bracings). For strength, I used brass angle for the corner angles, attached to the van end and buffer beam using cyanoacrylate.

The body was sprayed with Vallejo Mahogany Brown, which is a close match to the Heljan Railfreight brown, then a coat of gloss varnish followed before adding the transfers. Finally a coat of matt varnish was sprayed over to seal the transfers. The underframe was reassembled and the brake handles altered by shortening and reshaping them, using photos as a guide. The underframe was then painted black and weathered slightly before being reunited with the body. The completed VDA van is shown in Photo1. Since the original Heljan sprung suspension was unaltered, superb running is assured.