How I constructed Beeston Castle using Thermalite blocks

Beeston Castle station on the Peckforton Light Railway is supposedly situated adjacent to the entrance to the ruins of Beeston Castle (see A tour of the railway). Since Beeston Castle station was constructed, ten years ago, my representation of this illustrious piece of medieval architecture has been a mound surmounted by an insignificant 'temporary' cluster of sandstone pebbles cemented together (see Progress Report 15).

Replacing this with something more worthy has been on the agenda for some time and now has at last been accomplished.

Before starting work, I considered various ways in which the walls and towers of the castle could be represented - cast concrete (eg see How I cast two overbridges in concrete), foamboard (eg see How I constructed the water mill), carved expanded polystyrene or carved Thermalite blocks. I was alerted to this latter technique by my good friend and fellow modeller, Greg Hunter - http://www.members.optusnet.com.au/satr/hebel.htm (Hebel is the equivalent of Thermalite in Australia).

Before starting work, I prepared the site by laying some concrete foundations for the walls and the gatehouse. I used my usual mix of three parts builders' sand to one part cement.

While this was setting, I bought two standard sized Thermalite blocks (215mm x 100mm  440mm) from my local builders' merchants (approx. £1.50 each).

One of these was sliced in two longitudinally with an old panel saw (it had lost a few teeth and so was no longer usable for wood, but ideal for this job).

One of these halves was shaped irregularly with the saw ......

....... and then cut into smaller pieces appropriate for the site. These were then scribed with an old flat bladed screwdriver and a pad-saw blade.

This process was repeated until sufficient wall sections had been completed.

For the towers of the gatehouse, two six inch wide blocks were cut from the second Thermalite block.

A card template (6" diameter semi circle) was used to mark out the shape of the tower ......

..... and it was roughly shaped with the panel saw.

This was then tidied-up with a flat-bladed rasp.

The battlements were marked out on the top of the tower (roughly 1" square) .......

..... and then a series of holes drilled to a depth of 1" using a masonry bit.

Holes were also drilled in the back of the tower to meet the vertical holes.

The top was then prised off with the flat bladed screwdriver.

The battlements were then tidied up with the rasp and the screwdriver. Mortar courses were scribed near the top of the tower.

Holes were drilled and linked between the mortar courses to represent arrow slits.

Mortar courses were then scribed around the rest of the tower ........

...... and then vertical lines were scribed to create blockwork.

The completed sections of wall were then test-fitted on site.

The bridge section between the two towers was shaped. To reinforce the joint between the sections, a couple of short lengths of rail were inserted into holes and then the bridge section was glued into place using exterior PVA.

The blockwork on the walls were then coloured using cement dyes, diluted and brushed into place with a small paintbrush.

The walls were then concreted into place using my usual mix of concrete.

When the concrete was half-dry and still in its 'green' state the mortar courses were scribed between the sections of wall.

In some places the blockwork colouring needed to re-applied. However, the outcome seemed to be a lot more impressive than what preceded it.

When all the concreting has set, I will give the give the structure a liberal coat of masonry waterproofing compound to help the Thermalite resist the ravages of frost damage.

However, for an outlay of under £5.00 overall, I think this structure is great addition as a backdrop to the station.