Large sacks of Sand
Several large sacks arrive on site ready for embedding the geo-thermal pipes

Trench digging begins
Digging begins on the trenches for the geo-thermal pipes. We are using a double trench method which means we have to dig down to a depth of 1.8 Mtrs where the first layer of pipes will be placed. This is then back-filled to a depth of 1.2Mtrs and the second level of pipes are put in place.

Large piles of earth all around the site
As the trenches were dug, huge quantities of earth had to be stored on the site. Careful planning was required before work started to ensure that the digger could get access to dig the required trenches. Also, we needed to use a mid sized digger in order to work within such a small area.

Large Trench
We found digging a 900mm wide trench very dangerous because the quantity of sand sitting just below the soil at a depth of about 1.2Mtrs made the sides unstable. These regularly kept collapsing. In the end, we decided that as we needed two trenches side by side, it would be easier to dig one large trench 2.7 Mtrs wide. This proved much easier and far safer to work with.

Wide trench
On the final trench, we decided that for safety it might be better to use a 120cm trench bucket with the digger and just dig down to a relatively safe 1.2Mtrs. Once reached and levelled off, we then dug a further 60cm to reach the full 1.8Mtr depth required for the lower pipe run. This turned out to be a very efficient and fast way of working.

Gill digging to 1.8Mtrs
Once we reached the safe 1.2 Mtr depth we found it easy to dig down a further 600mm using a minimum width spade. Sand was then placed in the hole and the lower pipe dropped in. Sand was then placed on top and the thin hole backfilled.