How I cast a loading bank in concrete

The principle outgoing freight from Bulkeley Station on my railway is soft fruit, and so I decided a loading bank would be a useful feature to enable the local fruit growers to transfer their produce from horse drawn cart, steam lorry or these new-fangled motor lorries to box vans. Previously, I had constructed a cattle dock with Jigstones castings (see How I constructed a cattle dock), but since then I have sold my Jigstones moulds and so this option was not available. I did consider making it from timber, but decided I wanted something a bit more robust. Having cast a couple of over bridges in concrete (see How I cast overbridges), I decided to use the same principle for the loading bank.

Firstly, I surveyed the site to decide how long and wide the loading bank could be.

I figured that it could be 12cm wide and 105cm in length, following the curve of the siding.

To keep things simple, I decided to create the curve with a series of straight sections as this would make the shuttering easier to construct.

To hold the shuttering in place, I decided to drill holes in the concrete (breeze) blocks which form the trackbed for my railway (see How I lay my track) at a regular distance from the nearest rail to the loading bank. The ends of the sleepers actually proved to the the ideal spot for each hole.

Plastic rawlplugs were then inserted into the holes.

The next stage was to prepare the shuttering. Matching lengths of 2" x 1" and 1¾" x 1" timber were cut. As one side of the shuttering would be resting on the sleepers, it needed to be ¼" narrower than the other side.

To ensure the holes in the narrower piece of shuttering were in the right places, each piece of shuttering was rested on the track and the position of the relevant rawlplugs was marked on the underside.

Holes were then drilled through the shuttering to coincide with the marks.

Before the shuttering was fixed into place, the inside of each piece was marked to represent random stone blocks.

The mortar courses were then picked out with glue from a hot glue gun.

The narrower pieces of shuttering were screwed to the rawlplugs and the other side connected to them using spacer pieces.

As the outer edge of the loading bank extended beyond the breeze block foundations and so the easiest way to secure the furthermost side from the track was to use the spacers - otherwise I could have used rawlplugs to fix outside pieces of shuttering.

Three parts sand and one part cement was mixed with a couple of sprinkles of black and red cement dye. This was trowelled  into the shuttering and puddled down with a short piece of wood to try and eliminate air bubbles.

The concrete was left for 24 hours and then the shuttering was carefully unscrewed. The concrete was still in its 'green' state and so quite fragile and so I had to be very careful not to damage the mouldings.

The stonework had come out quite well. One advantage of working on the mouldings while the cement was green was that any imperfections on the top surface could be smoothed off with a trowel.

I left the mouldings to set for another 24 hours while I worked on the slabs for the surface of the loading bank. I decided to make these from 5mm foamboard, which I had to hand after the construction of the boiler house for the sawmill (see How I constructed a boiler house - pending).

Sixty-six 20mm x 30mm slabs were cut out.

The upper edges of each slab were then chamfered with a knife  ........

...... until all sixty-six had been done.

The upper surface of each block was textured .......

..... by dragging a flat-bladed screwdriver randomly across the surface.

The underside of each block was scored to help with the adhesion of the glue.

The slabs were then given a couple of coats of red oxide primer from a Halfords rattle can aerosol.

To fix the slabs to the concrete base, I opted for Gorilla Glue. As this is activated with water, the surface of the loading bank was dampened ........

.... and a small strip of Gorilla Glue was then applied to each slab .......

...... before being fixed into place, leaving a gap of 2-3mm between them, ......

...... until all sixty six had been laid.

Offcuts of wood were then carefully placed on the slabs and weighted down with bricks and rocks. Gorilla Glue expands as it sets and so the slabs needed to be held in place until the glue had set.

After another 24 hours, the weights and wooden planks were removed. Unfortunately, some of the slabs had lifted,presumably where the weights had been insufficient.

The worst offending slabs were prised off with a flat-bladed screwdriver ..........

....... and re-glued, this time with lead weights placed on them.

Once the glue had set, excess glue was chipped off with a screwdriver blade. SBR additive was painted on to the top surface of the loading bank and a sloppy mix of concrete with 50/50 SBR and water was prepared. The concrete was then applied to the top of the loading bank and between the slabs.

When this had set, the slabs were picked out with sandstone coloured acrylic paint.

The 'blocks' on the sides of the loading bank were painted with watery cement dyes - a mix of red, brown and black, varied in tone.

The loading bank was then tested.

In reality, a loading bank such as this would have been wider. However, space was tight and I wanted to leave some space for horse drawn wagons to be able to pull up beside it. Hopefully, as it is constructed from concrete, it will survive the ravages of the weather quite well. The slabs are a bit too bright and garish at the moment and so I will tone them down with wash of mucky cement dye. Also, in time, the paint and dye colours will fade.