WM Plant Hire recently deployed their specialist ‘Spider’ excavator along their long reach machines to assist critical emergency embankment repairs that closed the line between Tunbridge Wells and Tonbridge in Kent
Calling in the ‘Spider’ Due to access restrictions to the site and overhead powerlines, the solution of using long reach excavators to reach the failed slope was not possible on one of the sections. Main contractor BAM Nuttall worked closely with their long-term specialist WM Plant Hire for the reach options and agreed on the Spider machine. ‘Being long reach specialists means we are constantly pushing the boundaries to solve problems. Specials like the 13 tonne Batemag Spider and 26 tonne CAT zero tail swing long reach are two such rare examples, perfect for difficult access and steep slopes where conventional machines don’t cut it’ says WM Plant Director Damian McGettrick. Working directly on the slope the Spider excavator was coupled up with a safety line and began the task of clearing the material, placing it outside of the overhead risk zone for removal by the 22-metre long reach alongside. Fitted with a 360-degree tilt rotate unit allowed any angle to be achieved with any buckets or attachments. The individual hydraulic legs made it possible to position the excavator on steep slopes over 35 degrees with stability derived from the ‘spider’ legs. A high power to weight ratio provides hydraulic power more in keeping with 21 tonne class excavators.
Prolonged rainfall caused a landslip to occur at High Brooms picked up by remote monitoring sensors in the same area. Engineers were immediately despatched to investigate and assessed the risk leading to the line closure. Fiona Taylor, Network Rail Route Director said: ‘It is essential that our railway is safe to travel on. We’ve had exceptionally wet conditions this winter driven by climate change and have suffered a number of landslips across the Southern region. This is a long-term challenge we’re facing and by taking another week to do this work, we can protect the line for generations to come.’ During the closure Network Rail managed to implement a permanent fix along the 160 year old cutting, which included regrading, soil nailing and netting to ensure no more slippage occurs. Over 5,000 tonnes of spoil were cleared and removed by train from the site.
Huw Jones BAM Nuttall’s Divisional Director, commented: ‘This work demonstrates the ingenuity, responsiveness and broadbased skillset of our team…working hand-in-hand with our rail supply chain partners, we were able to get the line open again less than three weeks after the slip was detected. I’d like to thank the whole team for its dedication and commitment to excellence over this period.’
For more information on the ‘Spider’ and other specialist long reach machines get in touch via the contact information below.