Problem: These Blast Fences were a design and build solution that would protect plant and personnel working on a runway behind the breakaway thrust of Boeing 747 aircraft. We also had to limit the height of the fences to allow the wings of taxiing aircraft to pass over them.
Solution: Firstly, we developed a design principle that allowed us to calculate the wind velocities at various distances with different fence configurations to give us the optimum solution. And secondly, we decided that the perfect solution was a hydraulic system which allowed the fence to be raised or lowered within 15 seconds avoiding any risk to aircraft. The hydraulics were fully redundant so any single component failure would not affect its operation.
