Action Day at Wallbridge – Story One
Wednesday 19th January was a gloriously bright day… the sort of January day that all canal users enjoy. A nip in the air and clear blue skies reflected in deep still water. But, how deep is it now and how deep will it be?
The Mitcheldean based surveying company, Monument Geomatics, were there with some high tech equipment and a boat. (Well, a dinghy) to find the answers to those questions.
Monument Geomatics Chief Executive Marc Ashly explained that he and his team Richard Marston and Ashley Dyer have been contracted to conduct a Bed Profile Survey of the canal from Wallbridge Upper lock through to Brimscombe.
A bed profile survey uses the familiar ‘tripod and a person with a pole in the distance’ often seen at building sites. But this is on water, hence the need for the dinghy.
Ashley Dyer, seen here left, explained the use of his tripod mounted Total Station.
The electronic device sends an infra-red beam, which reflects off a prism that is mounted on top of a Detail Pole held by his colleague. The equipment measures angles and distances.
The picture below shows Marc Ashly holding the Detail Pole to take two measuring ‘dips’ at each position.
The first goes down into the water as far as the silt. The second passes down through the silt to the hard bed of the canal.
This process is repeated every 50 metres along the canal with up to ten dip points across the width of the canal.
Richard Marston explained “Obviously we use the dinghy where we can but where it won’t float it is down to us in our waders.”
Work continues next Monday and we wish the Monument Geomatics team more blue skies and ice free water.
Click on the icon below to find out more about Monument Geomatics.