Spinnaker Tower, Portsmout

Portsmouth’s Spinnaker Tower is a Millennium project and a local landmark. At 170m high with an observation platform, it is built on a piled raft at Gun Wharf, a retail development within Portsmouth harbour.

Carillion Piling constructed 1400mm diameter piles in the harbour at Portsmouth adjacent to Gun Wharf to support Spinnaker Tower, a large landmark visitor tower. This project presented a number of logistical and environmental challenges.

The piling works were undertaken from floating craft in tidal conditions. The tidal range was in the order of 6 metres. The harbour was very busy especially with ferries. The site was in a constrained area, this necessitated careful planning of craft movements and material deliveries.

88, 1400mm diameter piles were constructed. The depths of these piles varied from 36 metres to 51 metres. Each pile required permanent steel casing. Polymer drilling fluids were used to support the pile bores during drilling. Two piles were load tested using adjacent working piles to provide reaction.

Client: Portsmouth City Council
Piling rig used: Casagrande B220
Contract value: £2.4m