Barnfield Construction Limited approached P&D Environmental to assist in the drain down of the Leeds and Liverpool canal outside Weavers’ triangle, Burnley. The scopes of works were to supply specialised plant and labour to assist with the installation of stop logs and the drain down of the canal. The works were implemented over the winter shut down of the canal network.
The works were required to facilitate the removal of an abandoned sewer main that went below one of the buildings that were being re-developed. The building showed significant signs of subsidence in the location of the old sewer pipe, the pipe had to be removed from the canal bed and both ends grouted to prevent any further movement.
P & D Environmental limited were contracted to cut and install the timber stop logs, supply marine plant to carry out the installation of the timber stop planks, install bulk bags to act as a sump area to contain water ingress, removal of fish and de-water the canal.
The main works entailed the open cutting of the canal from bank to bank, the grubbing out of the sewer pipe, and the pressure grouting of the remaining ends of the pipe, the re construction of the canal bed and re sealing of the puddled clay.
Due to space being at a premium, large pumps had to be used for the drain down of the water, a hi-ab lorry had to install the pumps on a small platform beside the canal to prevent the public from accessing the pumps. Before the canal could be drained P & D Environmental limited had to undertake the fish removal and relocate the fish to the unaffected sections of the canal, in order to carry out the fish removal, all permits and consents had to be arranged.
After the fish removal work the de-watering of the canal was carried out this was achieved over a 38 hour period. A small amount of water ingress was seen through the old stone work under the bridge at the location of the stop logs, this was contained with the use of a 3’’ pump over the course of the work.
The works were completed on time and P&D Environmental re-attended site to re flood the work area in a controlled manor. As the canal re flooded the props were removed and the small excavator was re-loaded on to the pontoon, the stop logs were lifted from the channels and transported back up the canal for offloading.
Once the timbers were removed, pumping equipment was de-mobilised from site and bulk bags lifted from the water. The canal was now fully re open on time for the start of the boat traffic.
