Access to underground chamber systems is often achieved by lifting manhole cover lids; inserting lifting keys into their keyways, then lifting the lids from the frame and placing them on the pavement surface near the chamber opening.
A keyway full with debris leads to incorrect lifting of a manhole cover out of the ground. This can often take much longer than required and can be potentially dangerous to operatives.
Manhole lid keyway pockets are often filled with debris which prevents the insertion of lifting key equipment to such an extent that operatives attempt other unsafe methods of lid removal.
A long time can be wasted on site by operatives attempting to clear keyways enough to allow key insertion, particularly where covers have not been accessed for some time.
We have solved this common issue with a simple, but effective remedy: An anti-blockage keyway insert which fills the lid keyway pocket with a material prevents detrimental debris ingress, but allows the insertion and rotation of a lifting key.