Diamond Drilling

There's a lot happening on site at the moment.  The blockwork is finished on the biomass boiler house so it's ready for the horizontal steel supports that will hold up the roof.  The landward end is being backfilled ready for this.  Damien Summerscales, who is putting in the strengthening rods - see last week's post - has nearly finished, and the architect is due down this weekend, so hopefully work can start shortly on the roof of the main, north block.

The main interest today was a team from UKdima Engineering Ltd, site drilling specialists, of Stirling, who were there to drill two 450mm diameter holes through the base of the castle wall into the room which gave access to the well.  The holes angle up at 15 degrees.  One will take the biomass boiler extract, which will go up one of the castle chimneys, the other will carry the water and drainage pipes.  The heating system will access the castle through the well itself.

The men on site today were Alasdair Smith, right, and Liam Martin, who were kind enough to show me how their machine worked.

The drill holes are passing up through a blockwork buttress which was built last week.  The bit works very much on the same principle as the attachments I have for my hand drill which I use for making large holes in wood.  The rotating drill bit - blue - has to be forced against the rock wall, and this is done by turning a handle which connects a cog to the ratcheted steel rail that angles up beneath the bit, this rail being bolted to the blockwork.

The two black pipes are attached to a hydraulic unit, from which fluid is pumped to turn the drill bit. The yellow pipe is for water to cool the 'sharp' end of the bit.

As with oil-drilling bits, the teeth here are tipped with diamonds, which....

....can be seen in close-up here.  How long they last depends on the hardness of the rock.

Alasdair and Liam arrived on site yesterday and hope to be away by the weekend, though much depends on how resistant the rocks of the castle wall prove to be.

Many thanks to Liam and Alasdair for their patience in explaining their work.