Tuesday, 19 March 2013

Sub-soiling on the Helm Crag path

Last year we started work on a section of footpath on Helm Crag using a technique known as sub-soiling. We were helped originally by a group of volunteers on a National Trust Working Holiday and we recently re-visited it with a few of the Fix the Fells volunteers.

The weather was at times bitterly cold and there was continual flurries of snow, but when you've got your head down working it doesn't take too long to warm up.

The fence in the photograph below shows where we finished last year. The plan was to continue the path and put in another bend. Zig-zagging the path like this reduces the gradient and this in turn helps to stabilize the path.

Starting where we finished off last year

The idea is to dig off the top layer of soil until the harder (sub-soil) layer is found. This hard layer is removed, the soft upper layer is put into the hole and the sub-soil is placed back on top of it. The soil layers are basically being inverted.

It wasn't too long until the turfs were removed from the new section of path and the soil beneath them had been dug off.

Digging off the path

The next photograph shows the path with a drainage channel to the left. You can see now how the path is starting to develop. The soft material has been put back in and has been topped with broken rock and the sub-soil, which is the red-coloured material. This red soil compacts down really well and makes an excellent surface.

Topping the surface

By the end of the second day we had completed another section of path and turf lined the drainage channel. We've still got a little bit further to go until we've completely finished this section, so we'll crack on with it again later this year.

The finished section of path

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