Page 18 - January February 2014

The Fildid & Wissat RR – a Garden Railway
Nick Prior
PART 4: Hard Landscaping – Rock Building
The rock we obtained from Wales came graded in two sizes, but within each grade the pieces came in a range of shapes and sizes. So we soon realised that building the rock walls would have to be conducted in the way a farmer would build a dry stone wall, with each rock being chosen to fit with the previous one. To achieve this, a selection of pieces of different sizes were laid out around the site and while our son Philip, who is an experienced brickie, actually built the walls, my job was to select the right sizes and shapes of rock. In the early stages this was very much a matter of trial and error, but as the work proceeded it became easier to select appropriate pieces.
We realised that it was important to select flat stones for the bed of the river, therefore these were chosen first. The building of the river the way we wanted it turned out to be an intricate task and is described in detail in the next article.
Philip decided that the walls should be built on concrete footings for stability and that the rock pieces should all be cemented together. For this purpose we hired a cement mixer, which was sited on the front drive. Through the process we used more than a ton of sand, plus shingle and more bags of cement than I can remember. Philip’s experience of wall building and his insistence in doing things thoroughly has ensured that after more than seven years none of the rock formation has shifted.
We found that in practice it was better to partially dig out and build the walls at the right­hand end of the site before finalising the sculpting and building at the left­hand end on the other side of the river. Indeed the left­hand end turned out to be more building up than digging out. Photo 1 shows the rock face for the right­hand end lower level completed and the footings in place for the intermediate rock face.
Since we wanted to create rock faces that looked as natural as possible, we did our best to provide variation along their lengths. For example, having chosen a dogbone shape for the lower level we decided it would be nice for the rock face to curve around at the right­hand end to make it appear that the track was following a natural curve. This was not only intended to give a pleasing effect but would also maximize the mid and upper levels at this end. To give added shape to this face we also experimented with bringing the base of the face forwards at one point, not only to vary the face but to necessitate the track curving around it. We were pleased with the result, the effect of which on the track layout is shown in Photo 2. We were helped in this arrangement by finding a couple of very large stones, and we then staggered the higher stones in the stack backwards to achieve the desired effect.
When building the walls we left spaces along the top to allow the level behind to have varied contours along its edge, and for example allow a dry stream bed to be created as shown in Photo 3 midway between the river and the right­hand end. As you can see, this extends from the top level all the way down to the lower level through gaps in the intermediate and lower rock faces, with the bed sculpted out between the rocks. Interestingly, we have found another entirely natural effect. The whole area where we live is an ancient wood that pre­ sumably used to absorb huge quantities of water. Now the wood is mostly built on, the hillside is riddled with underground streams. As a result we get a lot of water seepage in winter and the dry river turns out to have natural water flow in winter and after heavy storms in summer. We also left some gaps in the wall structure to provide spaces for plants to be inserted.
At the left­hand end of the site we took advantage of the greater dimension of the slope at that end and the need to provide a flat surface for the upper loop, to create a more commanding wall structure that would dominate this end and balance the trestle which we planned for the right­hand end. The result is clearly seen in Photos 4 and 5 where you can observe that we
not only built the structure to the level of the upper track but also created a raised plateau within the reversing curve of the loop (see also Photo 3 in which you can see that the rock wall extends right round behind the plateau). With this arrangement the track extends along the lower wall on a curved ledge with rock faces above and below it. With delusions of grandeur on my part, the intention was to mimic the High Line on the Durango & Silverton.
To break up the front of the rock face we decided to create a short tunnel feature beneath which the lower loop would extend. In creating this we took advantage of a very large flat rock which, as can be seen, rests at the back in the rock wall and at the front on an outcrop using stones chosen to create a ‘piled­up’ look. My wife has always referred to this as the flying buttress. We had more ambitious plans for a tunnel where the end of the loop extends past the side wall of a flight of steps, the idea being to camouflage this wall as much as possible. Since the top of this tunnel was right at the top of the structure, its appearance needed to be more random and broken up. We therefore created a former of strong wire mesh as shown in Photo 6. The tunnel was built around this with the stones firmly cemented in place, and once the work was completed and we were sure the cement was properly cured (we left it a couple of weeks) we removed the wire cage by deforming the sides so that we could extract it through the tunnel mouth. A fiddly job requiring some effort to bend the mesh, but successful. This tunnel has survived the intervening years, although we actively discourage people standing on it.
LEVELS
It is important at the hard landscaping stage to be clear about levels across the site. I wanted the lower and mid levels to be connected, and this necessitated the back run of the lower level being arranged on a rising gradient towards the short lower tunnel where a point connects the lower track with the inter­ mediate track.
I wanted the upper track loop to be gradient free and it was important to get the level of the High Line correct to match the eventual trestle structure which itself, as previously mentioned, was to be given realistic dimensions by lowering the upper loop about 15 inches below the lawn level. This arrangement required another rock face along the edge of the lawn behind the upper loop.
This rock face was to be built using the slate pillars shown in Photo 6 of Part 4 (December 2013). My initial thought was simply to lay the complete pillars in overlapping fashion. In retrospect this seems to have been a rather blunderbuss approach considering the care we had taken with the other walls. Indeed we quickly realised that this looked unnatural and we set to work carefully splitting the pillars and breaking the resulting pieces into shorter lengths. Fortunately, once these were stacked in place they resulted in a rather realistic­ looking rock face with all the pieces different. Having been disappointed with the initial look of the unbroken pillars I was very pleased with the final result, and the rock face here blends very well in texture and colour with the Welsh slate used elsewhere. We also satisfactorily achieved our aim of creating a realistic wall face with very little depth.
Next: HARD LANDSCAPING – The River
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