Lister 5/1 Diesel

Drawbar Trailer Design & Build

Designing & Building Our 6-Wheel Drawbar Trailer Page 6


Once we had the chassis more or less ready to build up, we got all of the extrusion material down from the factory where it had been delivered, mostly on our shoulders! We live two streets away from the factory so it was just as easy for two of us to walk down with the lighter pieces. Cutting to size was an issue, particularly with the larger width of the side rave extrusions, and we eventually finished up using a steel 1mm cutting disc in a hand grinder to achieve some accuracy and finish. We did buy a circular chop saw, and that was OK for some parts, but the small cutting disc did far more work.

Rita stands at the front of the house while I take a shot of the chassis, just after we started on the body.

We had to build up an outer framework of side rave extrusions, so that when we came to fit the body sides and front and rear panelling, they would have somewhere to fit onto. The support extrusions were on pretty quickly, less than a day if I remember rightly, but then we got into the corner extrusions and the side rave extrusions, and it wasn't so simple!


The extrusions were stored on the floor by the trailer, wrapped in a green tarpaulin. We had regular visits by 'travellers' and the like, so we had to cover up anything that would be easily disposed of, not so much of a problem in 2012 when I am writing this, but in 2011 it was a big problem. The very long top cant rail extrusions were pushed down by the side of the house, as they were too long to go in front with the other stuff.

After cutting the large honeycomb sheets, the first two pieces are laid in place.


The next consideration before we got too far ahead of ourselves, was to fit the winch mounting before the floor was sealed in place. There are no bolts or screws holding the floor, it sits in place on beads of Parabond600 adhesive/sealer, and the top is sealed with Sikaflex 221. The winch was bolted through the floor on spacers, so that all stresses were taken to the chassis and not through the honeycomb.

The winch was a 5000lb pull 12V type from ebay, and it has done the job well.

Once we had the flooring sorted out, we had to strip off the protective film on both sides, which took two of us over an hour. Once it was off, we applied the sealer onto the cross bars and laid the panels in place. We then ran sealer into the joint between the panel and the chassis and left it to cure. Once it had gone off, there was no getting it out again, not without a lot of work.

On top of the flooring in the back, we had arranged for two lengths of heavy chequer-plate to go on top of the honeycomb sheet. This was to protect the surface against stones in the tyres of the engine trolley and general wear and tear.

The rear compartment floor in place with chequer plate and winch (Temporarily Installed)

The compartment where the engine was housed had to have four strong points for lashing the engine and trolley down, so we had previously arranged for four of the corner gussets on the chassis to have 16mm holes in them, and when the floor was fitted, we punched holes for the spacers and then bolted the eyenuts in place from below.

Hole in chequer plate and honeycomb for lashing eye.

Lashing eye bolted in place on its through-spacer.

In timeline terms, these eyenuts were fitted a week or so later than we are picturing it here, but it fits in better with the narrative this way.

We now had most of the floor covered, and we also had enough off-cuts to go over the side supports as well, giving us a full-width floor with almost no restrictions, other than the wheel boxes in the back which acted as mudguards. The panel on top of the front step was also cut and made ready, so that we could make a start on fitting out the side rave framework all the way round the chassis.


The framework takes shape as the flooring panels are fitted. One side rave extrusion is laid in place.

We played around with some odd offcuts to see how the side rave and corner extrusions would fit together, and how they compared with the theoretical assembly on paper. In fact they agreed pretty well, the biggest problems were dimensional creep and innaccuracy in measuring or cutting material. We would improve, but in the early stages it was all new to us and we didn't really have a lot of input, other than the Aalco rep who was very helpful.

Playing with bits and pieces one evening after dark.

The construction of the body was fairly simple and generally followed truck body practice. The outriggers carried the main body weight in the absence of cross-members, and each outrigger had a stainless steel bracket bolted to it, which then sandwiched the body panel between itself and the external side rave extrusion. All of the brackets were pre-drilled, so all we had to do was to place the body panel in place and drill through from the inside, then bolt it up.

One bracket, bolted in place but no body panel between it and the side rave extrusion..

As we moved round the chassis, we used off-cuts of GRP/Ply to space out the brackets so we could get the holes drilled in the right places. It worked out fine, but we knew that eventually we would have to bring the main sheets down from the factory yard where they had been for a few days.


Two main sheets of GRP/Ply sat on pallets in the yard, with the smaller front sheet on top, waiting to be cut to size.

The side panels, trimmed to size and with the cut-outs to fit the side rave extrusions on the chassis.

We continued with the side rave framing, and it took about a week to finish off, with one section having to be re-done as I wasn't that pleased with what I had done. Generally it looked pretty good, if a little complex. All of the nuts and bolts and brackets looked a bit Heath-Robinson, but once in place the side panels would smooth them out. The GRP/Ply sheets are 463 plus VAT each for the 23ft X 8ft sheets. 156 plus VAT each for the 8ft X 8ft sheets.

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