July 2010
The site for this track was a small stretch of dunes along the northern coastline of the Isle of Man. The ground itself was very undulating and underneath the thick covering of beach grass and bracken was 'wind-blown shelly sand' or what is normally referred to as 'beach sand'. This was significant because unlike certain other forms of sand there is no bind whatsoever in beach sand. The track design clearly had to take this into account as any obstacles would need to be built with the knowledge that they would break down very quickly. Sharp doubles for example are a waist of time in beach sand, but a basic ski off will eventually become a form of double/triple/quad throughout time as the bumps following it develop and get deeper. Undulating ground is always better than having a single aspect of slope and whilst there were no really big hills there were plenty of different gradients to play with.
It took around half a day to come up with a design. Given the nature of the deep sand and rolling landscape there were very few obstacles in the design. Except for a terraced shelf cut into the top of one hill, the track followed the natural ground very closely. 3 mid sized (20m) jumps, 2 ski offs, 1 small step up, a short rolling whoop section and a long section of shallow rolling whoops. The track had 23 corners, was 1701 meters in length and 6 to 7 meters in width. Just one machine was used - a Komatsu D61 and the job was complete in only 6 days.
The vegetation covering this land was growing out of a thin layer of comparatively fertile dark brown sand that had presumably been turned that colour through hundreds of years of the dead bracken and grass composting. I was concerned that if I stripped off the vegetation revealing the yellow beach sand underneath it would not be fertile enough for the grass to grow back. I took the decision to blade the track outline along the length of its route so as not to lose the vegetation. This would not normally be the practice as it would leave the track surface lower than the sides, but in this case with the yellow sand beneath there would never be a danger of lying water. The jumps were created with the grass and bracken I was blading off but in areas of the track where there was no obstacles a different approach was needed to get rid of the grass. Firstly I stripped around 10 meters of grass into a pile then bladed a slip (hole) of clean sand into a pile in the other direction. The grass was then pushed into the base of the hole and the yellow sand was pushed back over the top of it. Despite this process it was a very quick job and with just one machine was complete in under 90 hrs.
http://www.youtube.com/watch?v=3zusMz306iw |