TENSIONER INSTALLATION OF BRUCE DENNLA

INSTALLATION STEP 1

AHV LOWERS THE STRING OF EQUIPMENT TO THE MUDLINE, THE SWIVEL PREVENTS ANY TORQUE IN THE JUMPER WIRE FROM WRAPPING THE REACTION ANCHOR FORERUNNER WIRE AROUND THE JUMPER WIRE. THE LANYARD OPERATED SAFETY ARMING WEDGE ARMS THE SPRING LOADED RELEASE AS THE EQUIPMENT STRING CLEARS THE AHV STERN ROLLER.

INSTALLATION STEP 2

DRAGGING FORCE ON THE DROGUE CHAIN ORIENTATES THE ACTIVE ANCHOR AS THE AHV MOVES AHEAD OR ASTERN AT 0.5 KNOTS WHILE PAYING OUT WORK WIRE AT 0.5 KNOTS TO STRETCH OUT THE CROSS-TENSIONING SYSTEM ON THE SEA BOTTOM. THE REACTION ANCHOR HANGS IN A FLUKE-DOWN ATTITUDE FROM THE TRIPLATE WELL CLEAR OF THE JUMPER WIRE AND READY TO STAB INTO THE SEA BOTTOM. THE SPRING LOADED RELEASE ACTIVATES WHEN THE BOTTOM SUPPORTS THE REACTION ANCHOR.

INSTALLATION STEP 3

AS THE OPPOSED ANCHORS PENETRATE INTO THE SEABED SOIL, TENSION IN THE WIRE FORERUNNERS INCREASE UNTIL THE FIRST OF THE TWO SHEAR PINS IN THE SHEAR PIN PLATE PARTS. THE 11-LINK LENGTH OF CHAIN ON THE SHEAR PIN PLATE STRETCHES OUT AND CAUSES A DROP IN THE CROSS-TENSIONING LOAD. THIS IN TURN CAUSES A DROP IN TENSION IN THE AHV WORK WIRE WHICH IS RECORDED AT THE AHV WINCH SIGNALING THAT THE FIRST SHEAR PIN HAS PARTED. THE AHV WINCH LOAD JUST RECORDED IS THEN RE-ESTABLISHED TO HOLD THE ANCHORS FOR 15 TO 30 MINUTES AT CONSTANT LOAD BEFORE INCREASING THE LOAD BY, SAY, 10 PER CENT TO BREAK THE SECOND SHEAR PIN.

INSTALLATION STEP 4

WHEN THE SECOND SHEAR PIN PARTS, THE ACTIVE ANCHOR HAS BEEN INSTALLED TO A KNOWN LOAD, HELD FOR 15 TO 30 MINUTES, WHICH PARTED THE FIRST SHEAR PIN FOLLOWED BY A TRANSIENT PEAK LOAD 10 PER CENT HIGHER WHICH PARTED THE SECOND SHEAR PIN.

RECOVERY OF BRUCE DENNLA REACTION ANCHOR

AFTER COMPLETING RECOVERY STEPS 1 AND 2, A MOORING LINE IS THEN ATTACHED TO THE SUBSEA CONNECTOR MODULE ON THE FORERUNNER OF THE INSTALLED ANCHOR AND BUOYED OFF READY FOR HOOK-UP TO AN FPU OR FPSO.

BRUCE IS A REGISTERED TRADE MARK