Three tasks dominated this work party. The newt fences around the compound and Phase 1 were subject to some major surgery; a long run of stock fence on Phase 2 was completed; and the construction of the permanent base of the Phase 2 channel at Crickheath was pushed on. Although the weather during working hours largely behaved itself, the prolonged spell of rain in the days before the event made parts of the site a sea of mud, and kept the pumping gang in almost full-time employment.
Volunteer charity days have become popular with many large employers. On Friday we were hosts to two groups of five volunteers each from Openreach and Arcadis – the latter being the company responsible for the design of the Phase 2 channel. After a tour of the site and an induction they got stuck into remodelling various newt fences. As work on Phase 1 is now completed the now redundant newt fences were removed. Additionally the erstwhile fabric fences around the compound were replaced by plastic versions. Both groups worked very hard and, judging from the image, enjoyed themselves. They weren’t forced to wave – honest!
The largest group of volunteers worked on a 160 metre long stock fence on the offside to Phase 2. The purpose of this fence is to keep cattle away from the adjacent newt fence. The work took most of the first two days and used both mechanical and manual post knockers to produce a very smart looking fence.
On arrival at the site on Friday much of the channel at Crickheath site was flooded to a depth of half a metre or so and thus the first task was a lengthy bout of pumping. The water comes from a stream which drains a large area of adjacent farmland and enters the Crickheath compound. In days of old this stream connected to the culvert near Pryces Bridge via a ditch along the offside of the canal. Over the years subsidence has destroyed the ditch and the water now flows into the channel.
Even with four pumps in use it took until the morning tea break on each day to be able to see the bottom of the channel. The pumping involves considerable volunteer effort – not just setting them up but also keeping them free of the debris which rapidly causes blockages. Eventually the channel was excavated to below grade, and following an application of cement grout and covering with sheets of geotextile and geogrid, stone was spread to bring the level up to grade. It was encouraging that the section of the channel bed treated in this way during the last work party was more than capable of taking the weight of excavators and dumpers.
We have now had a little experience of work on the Phase 2 channel and it is already proving to be more difficult than what went before. In this connection the observations by one of the geotechnics specialists who were our guests on Friday were telling. He had never encountered a site which had such a variety of soil types or where the ground conditions changed so abruptly and so frequently. We have so far managed to overcome the various problems associated with the site and look forward with trepidation to the future challenge.