The Missing Mile: 300 Metres Dug and Discoveries Unearthed
By Andy T.
Autumn has arrived and bang on cue the weather has changed which will undoubtedly slow down progress digging the Missing Mile. The first showers thankfully suppressed the dust but quickly turned the layers of dust into a very sticky slurry.
We have made cracking progress during the dry weather with at times volunteers working 4 days per week. To date we have dug in the region of 300 metres on the east side of the motorway with all three excavators and the four dumper trucks being extensively used.
The first section of 150 metres has been lined with clay and is ready to receive water. Applying the clay lining has been a real challenge. A combination of techniques has been developed; working from the top of the bank with an excavator, from the base of the canal and along the banks using a sheep’s-foot remote control roller. This is the slowest part of the process.
The stability of the roller has caused a few problems, it appears to find any soft spot in the clay, gets stuck and at times does tend to want to lie down on the job !! This then requires assistance from one of the excavators to stand it up again.
Digging for the new lock has now commenced, as this will be the deepest dig several challenges will have to be addressed. The dig will be created using terraces, each approximately 1 metre wide and deep, this approach removes the need for piling or shuttering and will also make the back fill task easier once. Water management will cause problems as the base of the dig will be below the water table. To combat the continual ingress of water two sump holes will be dug with float-controlled pumps running full time.
Luckily most of the digging has revealed a clay base, however in one of the pounds gravels have been found, these need to be dug out and replaced with clay. The size of the gravel deposit is being explored; however, it extends below the water table so every hole we dig rapidly becomes a metre deep puddle.
In the gravel animal bones were found, a mixture of ribs and vertebrae. Luckily the Water Recovery Group were on site and one of their team was able to identify the bones as from either a small cow or a horse, further research is required.
Alongside the animal bones the team have identified an archaeologically interesting area, pieces of roman pottery, post holes, remnants of preserved post and planks alongside a number of un-known objects and smaller bones. To preserve the material progress has now stopped and an exclusion zone created around the site. We await decisions from the archaeologists on the next steps. Watch this space for updates.
