Southsea team preserving historic walls


Historic seawall remains are in good hands, thanks to construction techniques employed by Portsmouth City Council’s Southsea Coastal Scheme.

The Scheme is using specialised hydro-demolition to remove concrete to the east of Spur Redoubt, where it is in close proximity to 17th century historic walls that were recently uncovered during revetment clearance.

The method is being used to demolish concrete walls without damaging any historic fabric and is conducted under the supervision of an attending archaeologist.

Metal sheeting has been deployed to protect historic walls, as well as a netting enclosure to contain flying debris.

Southsea Coastal Scheme Technical Lead Chris Koster said:

“Since the Southsea Coastal Scheme started in September 2020, we’ve been committed to protecting the historic discoveries that have been uncovered during our works.

“Right now, we’re using hydro-demolition which involves using high-pressure water jets to strip newer concrete from the remains of recently unearthed historic walls.

“This vibration-free method is ideal for the project as it’s a very specific technique that only removes concrete from a targeted section, so it avoids damage to sensitive areas.”

Once hydro-demolition is over, the exposed remains will be covered over after being surveyed and recorded by Wessex Archaeology, in consultation with Historic England and the County Archaeologist.

The Southsea Coastal Scheme is the UK’s largest local authority-led coastal defences’ project, worth more than £100M. It will stretch for 4.5km from Old Portsmouth to Eastney.