Work Begins On Major Drainage Survey Of Severn Tunnel - continued
The culvert ranges up to 1200 mm wide and up to 500mm tall. Over a number of decades, the original brick-built culvert has been repaired, so in some places is lined with concrete or steel.
One of its main tasks is to collect water from the ‘Great Spring’ which seeps into the tunnel. An estimated 50 million litres of the spring water are pumped from the tunnel every day and released into the River Severn.
The joint Lanes Group and Amey teams had to walk three miles to the Welsh end of the tunnel, then up to another mile into the tunnel, to reach their work sites, with equipment transported on rail trolleys.
Working in 12-hour shifts, two four-person teams - made up of two CCTV survey engineers and two Amey track operatives - worked away from each other from a central point, overseen by a Lanes Group supervisor.
Robotic crawler cameras were used to record HD-quality video of the inside of the track culvert. This method was augmented by the deployment of zoom-focus pole inspection cameras.
Lanes Operations Manager Mark Scott, one of the site supervisors, said:
Where track ballast had blocked the culvert, stopping the crawler camera from getting through, the pole camera allowed us to look past the blockage and ascertain its condition.
It was one of the approaches we devised for this particular project to allow us to maintain high levels of productivity in challenging conditions, as we want to achieve as much as possible in the track possession time we have.
The Severn Tunnel was built by the Great Western Railway between 1873 and 1886. It held the record as the longest main line rail tunnel until the High Speed 1 tunnels in Kent opened in 2003.
Beam Grab Improves Delivery of Precast Elements
Lynx Precast supplies a range of products to all sectors of the UK construction industry including housebuilders, main contractors, groundworkers, civil engineering contractors, builders merchants and self-builders.
Lynx Precast understands that each site and customer has different delivery requirements and expectations, and that when delivering its products, vehicles and material handling attachments must be specified to suit.
To aid in delivering customer service, Lynx Precast contacted B&B Attachments to supply it with beam grab attachments.
The grabs fitted to Lynx Precast crane delivery vehicles, assist in the smooth delivery process of beams where “supply only” customers do not require the aid of mechanical offloading facilities on site.
Each Beam grab, with optional lifting hooks and a rubber pad gripper arrangement, is designed to pick up a range of different sized beams and profiles. Lifting either 4 or 6 beams at once, the beam grabs supplied to Lynx Precast also have individual ball lock valves fitted, which enables single beams to be clamped and released when required.
The universal crane mounting plate enables the attachment to suit various adaptors, and the quick release couplings allow a quick change over to alternative attachments when required.
Our customers are our priority. We wanted to make our delivery process as smooth and as safe as possible. The Beam Grabs supplied and manufactured by B&B Attachments have helped us to achieve this. The ease of use and reliable operation of the attachments when moving our products has also helped improve daily productivity.
says Andy Teasdale, Managing Director at Lynx Precast.