- Often built in front of seaside resorts.
- Very expensive.
- They aim to completely block the waves and their effects.
- Life span of approximately 75 years.
- Can cause the erosion of the beach in front of them.
- Socially reassuring for local residents.
- Wooden "fences" built at right angles to the coastline.
- They aim to stop the movement of material along the beach due to long shore drift.
- Their primary intention is to build up the amount of sand on the beach.
- They have a life span of approximately 25 years.
- Large steel mesh cages filled with large rocks.
- Aligned at right angles to the coastline.
- They aim to do a similar job to wooden groynes.
- Expected life span of 20 - 25 years, as the steel will rust.
Rip Rap / Rock Armour:
- Large boulders, of 10 tonnes or more, are used as a sea…