Limpet Dam 

A roll on roll off ferry had collided with a unloading pontoon at Harwich International Port.The bulbous bow of the vessel had penetrated the side of the pontoon causing immediate compartment flooding and considerable structure damage.

The pontoon was fixed to restraint piles removing it would prove costly. Following a diving survey  Europa Diving proposed to repair the damage with the use of a limpet dam, this would create a dry environment to carry out the repairs.

Once in position the water would be pumped from the flooded compartment causing the limpet dam to seal against the pontoon sides and bottom creating a dry environment

3600 Kg/M2 of uplift ( hydrostatic Pressure ) alone would hold the limpetdam in position, however extra wire ropes were secured from the limpet dam to the inside of the pontoon for safety. Now our welders could go to work.