Lincoln Castle West Bank Stabilisation
After strengthening the lower retaining wall, Condor Engineering have started work on stabilising the slope of the West Bank. This is the critical section of the works and because of difficult working conditions due to the steep incline, Condor Engineering had to develop a unique drilling rig to allow safe installation of our bespoke mechanical anchors.
The drilling rig comprises of two sections, the chassis and the mast which holds the hammer drill. The chassis is a stabilised steel frame that is attached to an electric winch, which allows for easy and safe movement up and down the slope. The mast is controlled by a powered crank on the chassis. This allows the operatives to adjust the angle of insertion of the anchors.
The first job for Condor was to install a series of winch points along the top of the slope next to the castle wall, this was done by accessing the bottom of the castle wall via a shallower gradient slope on the south side of the castle.
A guide line had been installed onto the castle wall itself by our IRATA level 3 supervisor who is on-site to assist Condor Engineering and ensure safe working practice by all operatives. The first of the slope mechanical anchors have been installed this week, Condor Engineering is on course to complete this arduous project on time.
Condor Engineering excel in these situations due to our out-the-box approach to difficult stabilisation projects and years of experience having to solve unique engineering problems.
The next phase of stabilising the retaining wall involved using our bespoke load locker to apply force on the anchor bar which in turn enables the anchor head to turn and produce a compression effect on the ground between the anchor head and retaining wall. In effect squeezing the ground to give greater strength and stabilisation to the retaining wall.
The picture above shows the load locker in place and ready to be used. The process is relatively simple; firstly, an extender bar is attached to the anchor bar and then our load locker and its carriage are affixed to said bar. Secondly, a load plate and load nut are affixed to the end of the load locker.
Force is applied to the ram (Yellow Jack) via hydraulics to pull on the bar which turns the anchor head. Force is applied until the bar is loaded to two tonnes of pressure. The load locker is then removed from the anchor bar and a stainless-steel plate and nut are secured onto the pressured anchor bar. The bar is then cut flush with the nut to give an aesthetically pleasing finish.
Condor Engineering has an exciting week ahead as the operatives will be starting work on the slope itself, allowing them to use their newly acquired skills as IRATA trained operatives..
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