These two thames water sewer connections via timber heading we carried out on behalf of Balfour Beatty at the Queen Elizabeth II Hospital in Hertfordshire. The connections to the surface and foul water sewer systems had to be tunneled under the road so that the ambulances and emergency vehicles could still be used 24 hours a day.
We excavated the marked area for the sewer connection to reach the manhole, any of the unwanted spoil was disposed of to a registered tip. The timber frame was installed in the heading and this was built down until the water manhole for the sewer connection was reached. Any possible ground water was pumped out and directed to the nearest water drain.
On completion of the sewer pipe installation and packing the heading with concrete the drive shaft was reinstated with asphalt and compacted to 200mm depth. Our two sewer connections by timber heading allowed the vital works of the emergency services to continue unhindered.