Wave Protection to Caisson Breakwaters

Breakwater Wave Scour

Caisson breakwaters can suffer from loss of bedding material and settlement where wave or current induced scour occurs at the caisson toe. This can lead to cracking and failure of the breakwater. Water flows through the voids created, causing progressive failure.


Fabric formed concrete mattress can be utilised to produce an interlocking plain concrete slab sealed against the caisson wall, protecting the bedding material from wave action ensuring structure stability. The large interlocking slabs can be up to 1.2m thick, are highly durable, do not roll or displace like other modular systems and can be placed on uneven surfaces and slopes.


The formwork is laid, anchored to the structure, and pump filled in situ, adjusting to the undulations of the bed. For construction ease, panels are sized to suit the contractors required pour volumes, and the fabric units are lightweight and readily installed by divers working from the breakwater with land-based plant.


  • Reliable concrete position and thickness
  • Level & sloping beds
  • Avoids washout
  • Known grout pour volume – no losses
  • Environmental benefit – concrete containment