03 Jun - To Aberdeen, to install the ROVs
RRS Ernest Shackleton Diary
Position @ 1200 CET: 57° 17' North. 1° 40' West, 15 nautical miles from Girdle Ness Light.
Conditions: Wind North-west by west, force 5/6; Barometer 1020.1 mb steady; Air Temperature 10.2° C; Sea Temperature 9.2°C; Overcast and clear.
The final grab-full of mud from the seabed was brought onboard RRS Ernest Shackleton on Tuesday morning, 29 May, at 0900 CET, in a position some 250m off the Oseberg Field Centre Platform. Once the samples had been taken from the grab the task of preparing to demobilise started. With the vessel heading back to Haugesund the scientists and crew started packing the containers with all the samples, removing hardware and disconnecting the multitude of electrical cables and water hoses. This was a far quicker job than when setting up some two weeks previously !
A short period of time was spent during the passage to Norway to run some tests on our Dynamic Positioning equipment and the vessel arrived at the Killingoy Base Berth (Stolt Offshore), Haugesund at 1840 CET and by 2100 CET all the equipment and personnel had been discharged ashore.
During the night the decks were cleaned and prepared for the next work period, which will start on arrival in Aberdeen.
At 0500 CET, Wednesday 30 May, the vessel sailed from Haugesund and set course for Aberdeen for the overnight crossing. After a calm passage RRS Ernest Shackleton embarked a Pilot at 0600 on Thursday 31 May, who took us to our berth at Regents Quay, Aberdeen, where we were all fast, starboard side alongside, for 0700 BST.
Awaiting us on the quayside was a prefabricated structure, weighing about 22 tonnes, which had been designed to fit over the ships two forward hatches and onto which the control cabins for the Remote Operated Vehicles (ROV's) would be placed. Once the gangway was down the mobilisation started with personnel from Stolt Offshore and their appointed contractors coming onboard to move into cabins and get all the equipment prepared for the forthcoming survey of BP-Amoco assets in the North Sea.
In order to get the prefabricated unit onboard, two large mobile cranes were required, along with skilled knowledge of a foreman who would ensure that the cranes were correctly directed. The initial move was to get the structure from the position on the quayside to one beside the ship, and then to make the lift onboard.
Following a few minor teething problems, the structure was finally lowered into place. The welding teams then made a start on securing the legs into place on the deck, leaving the structure suspended over the ships hatches. Once secure, three containers were then lifted and welded into place. Once completed, the next stage of the mobilisation is to place onboard the three ROV's, two Lynx and one Tiger system. Then the long task of connecting all the wiring between the cabins, ROV's and Survey spread (for the supply of navigational data) in the Dry Lab Aft can begin.
The ROV's onboard are made up of several parts. Firstly there is the Launch and Recovery System (LARS), which is situated on the ship's deck and is used to deploy the Tether Management System (TMS). The TMS is lifted out of the LARS using a small crane mounted on the LARS, and then once over the water the TMS is lowered down to the required depth. Within the TMS is the ROV itself and once at the correct depth the ROV is then driven out of the TMS, which has 200 m of umbilical. Once the work to be carried out is completed, the ROV is then driven back into the TMS and this is then lifted back up onto the deck into the LARS. I hope to get some pictures of all the various component parts in due course to give a better understanding of the operation.
Also fitted during the Aberdeen call was a very large Satcom dome, measuring over 3 m and once in place it dwarfed the Funnel Top, where it had been placed. This system operates in a different manner to the Inmarsat system fitted onboard the ship for normal communications when the vessel is working down south. Inmarsat provides us with one single line that we have to access when required, and allows us the option of either phone, fax, data or telex. The system provided by the charterers gives us five permanently connected phone lines and one data line. All these lines terminate within the charterer's office in Aberdeen, and this means that anyone now wanting to phone us can do so by using an Aberdeen number and not an international number, regardless of where we are operating.
The mobilisation was done throughout the day and night with two 12 hour shifts being employed. The final task prior to sailing was to ensure that all equipment is secure for sea, as one never knows what weather is ahead of us !
With everything now ready the vessel prepared for sailing. The Pilot boarded at 1000 on Sunday morning to take us out of Aberdeen Harbour and to a trial site some thirty five miles away, where the two Lynx ROV's will be fully tested before making a start on the survey work. Once clear of the harbour a full fire and boat drill was held to ensure that all the newly joined personnel were made fully aware of what their muster points/stations are in the event of any emergency arising onboard.
Forthcoming events. Start survey operations