BAM Ritchies

Case Study: Padstow Lifeboat Station

Client: RNLI

Consultant: Royal Haskoning

Location: Cornwall

Date: 2005

BAM Ritchies undertook a major marine piling contract at Padstow, Cornwall for the new RNLI lifeboat slipway station. The work involved the installation of 41 tubular piles into rock sockets in a marine environment.

The drilling rig used was a unit specially developed by BAM Ritchies’ Plant Department for this marine operation and mounted on a jack-up barge. To ensure correct pile positioning, the rig moved along rails fixed to the jack-up.

Drilling to rockhead was carried out using a 980mm diameter conductor casing, followed by a NUMA 240 down-the-hole (DTH) hammer with an 864mm diameter button bit drilling a 5.2 metre deep rock socket. The hammer required a compressed air supply of 4,000 cfm at 12 bar. Biodegradeable oils were used throughout the operation.

Two different pile diameters were installed - 813mm for the boathouse and 752mm on the slipway. The pile tubes were grouted into position using a high strength OPC grout.