Abstract: Apparatus for providing an offshore drilling operation in a sea, the apparatus comprising a drilling derrick support structure (2) having a base (4) to rest on the sea-floor (5) and a deck (7) to support a drilling derrick (1), the structure being in the form of a concrete block (2) having a hollow cavity to enable the block (2) to be floated to the site where drilling is to take place and being adapted to receive ballast into the cavity in such a way and in a sufficient quantity as to cause the block (2) to sink base-first and rest upon the sea-bed with the deck (7) clear of the surface of the sea, a drilling derrick (1) for mounting on the deck (7) of the block (2) and a tender assist barge (3) for transport to the site in down to 2 m of water to provide services, supplies and equipment to the drilling derrick (1).

Abstract: A restraint coupling assembly is provided for a double containment pipe system having an inner carrier pipe formed from a first thermoplastic material and an outer containment pipe formed from a second thermoplastic material. The restraint coupling assembly includes a carrier component formed from the first thermoplastic material and having a carrier cylinder conforming to the diameter of the carrier pipe, and having a carrier flange extending rigidly outwardly from the carrier cylinder. The restraint coupling assembly further includes a pair of containment components formed from the second thermoplastic material. Each containment component includes a containment cylinder conforming to the diameter of the containment pipe. Each containment component further includes an inwardly extending containment flange having an aperture therein with the diameter of the aperture greater than the outer diameter of the carrier pipe.