18 July - Mattress laying
Date: Sunday 18 July 2004
Position @ 1200 Local (GMT+1): 53°01.0' N 002°20.2' E - on the Leman Gas Field off the UK Coast
Next destination: Hull, England
ETA: Tuesday/Wednesday 20/21 July 2004
Distance to go: 106.0 nm
Distance sailed: Unknown due to amount of to’ing and fro’ing in the Offshore fields
Total distance sailed: Unknown
Current weather: Overcast, fine and clear
Sea State: Calm sea and low swell
Wind: E Force 2
Barometric pressure:1014.7 mmHg
Air temperature: 14.7°C
Sea temperature: 15.2°C
Above: The position map of RRS Ernest Shackleton. Click to enlarge.
More Work Offshore
During the course of the week, the vessel that was in the Southern North Sea, has since moved back to Immingham on the Humber, had a swift turn-around and then returned back to the Offshore gas fields. A triangular course that has seen us right back where we started last week !
However, the week has also seen the completion of the initial Charter for Bluestream and commencement of another contract for the same Client - this time using the onboard ROV’s (Remote Operated Vehicles) to inspect pipelines and ‘risers’. Our work has been largely within the 500 metre protection zone around these Offshore Installations. But I am getting ahead of myself. We were laying mattresses only last week, and can now go to our ‘on the spot reporter’ for an in-depth explanation of the process offshore…
Above: Picking up a mattress. Click to enlarge.
The photographs best describe the laying of the Mattresses.They were rather bulky and unwieldy to manipulate, but the deck boys and the crane operators managed to send all 25 of them over the side and juggle them into position across an undersea pipeline in the Southern North Sea. First, the lifting frame was brought over the next mattress in the pile and positioned so that it could be stropped up.
Above: Mattresses on deck. Click to enlarge.
The Deck Crew would then put in the strops. 16 in total.Careful attention had to be paid to the condition of the strops as they were inclined to chaff and shows signs of damage during the course of the operation. With 10 tonnes of concrete mattress to lift, safety was paramount. Here we see our very own Wavey Davey on deck overseeing the stropping and taking-up-slack ready for the next lift.
Above: The lift begins. Click to enlarge.
Once everyone was clear of the lift, the tension was taken and the rather solid-looking flat mattress lifted like a rather heavy duvet.The difficulty with the lifting operation was that the sea is not a solid platform. It has a tendency to keep moving !!Imagine trying to thread a needle .. On A ROLLERCOASTER ! Once the main crane lifted the mattress directly up in the air, the laws of motion intervened, and the whole load became a Pendulum ! This is where the skill of the crane operators is most important.The swinging load is manoeuvred swiftly over the side where it is out of the way of the superstructure and over the sea.
Above: The mattress is over the side. Click to enlarge.
Above: Easy does it....click to enlarge.
Lowered to the water…
Above: Splashdown! Click to enlarge.
…and ‘Splosh’ – straight in the water.
AND THAT’S THE EASY BIT !
Now the DP Ship is moved slowly into position over the pipeline using acoustic transponders, and with the aid of the ‘eyeball ROV’ already on the seabed, we can see in the TV Monitors on the bridge the position and orientation of the mattress down below. It amazes me how precise the mattresses can be laid in position.‘Down 2 metres’. ‘Up 2 meters’.‘Move the vessel 1 metre Starboard’… eventually, the mattress is laid exactly where required across the pipeline, achieving the result of anchoring the pipe to the seabed. Now comes the tricky bit !
At this point we have the Mattress in position, but still with a lifting frame attached. And attached to the lifting frame is a cable. And attached to the cable is a crane. And attached to the crane is a whole SHIP ! How to part the two leaving the mattress behind ? That’s where the specially-designed lifting frame is important.There is a simple lever that the ROV can move and it releases all 16 strops simultaneously so that the lifting frame can be slowly removed from the seabed and recovered to deck so that the whole process can be repeated again !
Gripping stuff. And the result of the entire operation can clearly be seen on the underwater camera mounted on the ROV and displayed here on the Bridge !
as you can see,… TV Monitors do not photograph very well at all !!
Wavey Davey's Wit Spot
And now a double helping to see you through the Summer.
Davey says : ‘There’s a fish in his Grand Piano’.........‘But it’s alright, because it’s only a Piano Tuna’ !!
Two lads were paddling in the sea off Cleethorpes.
‘My, ain’t your feet dirty’, says the one.
‘Yes’. Replied the other. ‘We didn’t get to come last year !!’.
And after those efforts, aren’t you glad Davey is heading home this week and taking his own particular brand of wit with him ?
Thanks Davey – and have a good leave.
BACK TO PORT.
By Tuesday evening, we had laid the last of the Mattresses on the pipeline and then it was back to the Port of Immingham on the Humber for additional equipment and personnel. Bluestream had completed this one task and had others for the Ernest Shackleton to do.So we required additional equipment for Underwater Inspections and also additional Inspection Engineers.So welcome onboard ‘Douglas Barnett’ and his colleague ‘Steve Bancroft’.
HOW TO GO FROM ANTARCTIC TO THE NORTH SEA – CAREER-WISE.
November/December 1989 was the first and last time I experienced sea sickness!
I was returning home from Signy Island on the RRS John Biscoe (ZDLB), going through Drakes Passage having completed my two-year stay as the Diving Officer. Not the best of times to arrive home. Having been used to living with a maximum of 22 people for two years the thought of Christmas shopping with what seemed like the whole population of Swansea was quite daunting.
Having survived that, it was time to earn a crust and so back to the Diving, working first in local rivers and docks. Not quite as unpolluted as Signy! It wasn’t long before I started working in the North Sea, once again doing shallow air diving work for the oil industry. In time I went from the North Sea to the Middle East where the water was a lot cleaner and warmer!! Time to move on in the industry, so moved from shallow air diving to Saturation Diving where the limits are a lot deeper where you no longer have to ‘fin’ your way to the work site, you just walk along the seabed (so much more civilised!) The downside? Living in a decompression chamber for 4-5 weeks in which some you can’t stand up to your full height.
Throughout the Oil industry there is an emphasis on inspection and maintenance. It’s cheaper to repair an Oil Rig than build and install a new one so now there is a whole sub industry. Companies specialising in various modes of inspection, from Ultrasonics, Radiography, Surveying, Corrosion all the way down the line to a diver with a tape measure. Sometimes you might get all these on the same job. It can be a little hectic at times unless it’s co-ordinated correctly utilising as much as you can at any one time to reduce the time to do various jobs therefore reducing costs on daily hire of equipment and personnel to the clients i.e. the oil companies. This is something that I’ve now moved onto - finally getting out of the water as it were.
With all the above working on the various structures that needs inspecting, reams of data are produced which needs collecting and putting in some semblance of order and this all comes under the roll of the Co-ordinator - as well as writing up a final report to submit to the Client.
Which brings me to the present as I’m writing this from RRS Ernest Shackleton, which in the summer gets chartered, to companies working for the Oil industry. We are at the moment Inspecting a number of Oil Rigs looking for Damage, Corrosion and areas which could in time or in the right conditions be detrimental i.e. where pipelines are not supported by the seabed in regular places leading them to a possible rupture. So this is all inspected with the use of an ROV (Remote Operated Vehicle) with all aspects of the Oil Rig looked at and put onto video. Any suspect areas are commented on, gradually building up a history on certain areas, which if they were to fail, could be catastrophic to the personnel on the Oil Rig and the environment.
18 Years ago I sailed to Signy on RRS Bransfield to spend 2 winters. Now Signy is no longer a winter base and the Shackleton has replaced the Bransfield. Some say this is progress. For me, my time on Signy set me up for life with an experience some will no longer have the opportunity to have first hand. I wish they could. And this present vessel?… The Bransfield had a certain charm; the only progress here is I won’t be getting seasick!!
(Editor – he obviously hasn’t experienced the Shackleton in a head sea across the Drake Passage yet ?).
Written by Steve Bancroft.
Signy Diving Officer 1988/89
FROM IMMINGHAM, BACK TO THE OILFIELDS.
We had arrived in Immingham at 0915 on Wednesday morning (14th), after an overnight steam up the Humber and through the lock gates.
On the bridge the Master ably advised by the Humber Pilot had Mike, the 3rd Officer looking on.
Manoeuvring against the tidal Humber River, the ship was positioned for it’s entry into the lock gates on a grey morning.This was a marked contrast to the last arrival in Immingham back in May (23rd) when we had returning FIDS onboard, and didn’t get to the gates till late at night.
The reason for these lock gates at the Humber Ports is that being tidal, the River Humber can give a difference in water level of up to 6.5 metres in a day (Spring Tides), and so they keep the water level in the docks constant by use of the lock gate entry.This particular day (14th) the water level was to vary as much as 3.7 metres as seen in the Hydrographic Office’s Admiralty Tide Tables which list tidal forecasts for the year.
Once alongside, we had only 7 hours of loading and changing of personnel before the Pilot was back onboard and we were heading once again for the lock gates.For those who were on the night-shift, there was the opportunity to go ashore and travel to Grimsby for a little shopping, but for others it was business as usual onboard.For the next leg of Charter, we required an additional DPO (Dynamic Positioning Officer) and so sailed from Immingham after the arrival of Alan Peerless who drove up by hirecar.We had only said ‘goodbye’ to Alan on the 7th, so it was a very swift leave-period for him indeed.The additional DPO was necessary due to the nature of the work inside the Offshore Installation’s 500 metre protection zone.
With Alan safely onboard, the vessel departed once again for sea.
The remainder of the week could be described as ‘boring’ unless you get excitable about launching an ROV over the side to take reams and reams of video tape of underwater structures ? The inspection of the underwater structures and risers is well documented in previous North Sea Webpages, and here is a picture to remind you of a ROV-Eye’s view of the operation, taken from the 2001 North Sea Season.
Refer to Diary No.12 from 05th August 2001 which features the excellent pencil drawings of Barry Pearson.
The vessel’s Daily Position Report, or ‘posrep’ is produced by the Master and sent to BAS and Riebers ashore.
It sums up the typical day on Dynamic Positioning perfectly.
Vessel on auto DP approaching Leman platform.
1200‑ Vessel proceeding to Inde. platform
1425 ‑ Vessel entered 500m safety zone of Inde. Platform
1515 ‑ 1618 ‑ Tiger ROV deployed for riser inspection.
1637 ‑ 1910 ‑ Surveyor ROV deployed for pipeline inspection out to 500m.
1915 ‑ Vessel cleared 500m safety zone.
1927 ‑ 2025 ‑ Vessel on passage to next Gas Field.
2057 ‑ Surveyor ROV deployed for pipeline inspection towards the platform.
2110 ‑ Vessel enters 500m safety zone of next Platform.
2200 ‑ ROV recovered.
2245 ‑ Tiger ROV deployed for riser inspection.
Midnight ‑ Vessel clears 500m safety zone and proceeding to Leman Gas Field.
Author : Master RRS Ernest Shackleton.
SUNDAY : And today the last of the Riser inspections will be completed and with some remaining tasks to perform, we anticipate a return to Hull to demobilize early in the next week. The weather during the week has been balmy and sunny to grey, torrential downpours and squalls.Saturday afternoon saw a particularly spectacular lightening display at sea and when the rain fell, so did the temperatures and we were treated to a display of hailstones falling on the ship. The sky was totally obscured and dark as night, so the lights on the bridge were switched ON. But it soon passed and this morning, by contrast we were treated to the nicest of sunrises which although caught on the web-camera, cannot do justice to the majesty of a morning in the Southern North Sea Gas Fields in July.
Click on the Image to see the sun, the rig, the ship, and a perfectly beautiful morning.
Finally, our arrival in Hull this week will herald the end of yet another 4-month voyage for the Graham Chapman crew of the Ernest Shackleton.The Clients will all demobilize, the crews will change but the DPO’s will remain onboard to complete their 6 week tour of duty.We welcome onboard John Marshall’s team who will take you through the rest of the North Sea Season, the Portsmouth Refit and the journey down South to Montevideo where we will once again join you on the pages of the Ernest Shackleton Web Diaries.
So for this season , it’s ‘Cheerio’ and ‘Have a fruitful Summer’ from all the crew.
Forthcoming Events: Finish survey of the Risers, lay the remainder of the Mattresses still onboard, and when completed, return to Hull for our long awaited Crew change. The GPC Crew will disappear to the 4 ends of the country on leave to be replaced onboard by the JBM Crew. Next Job ?? To Be Advised.
Contributors this week: Steve Bancroft (ex-Signy) for his potted view of Antarctica to North Sea Career and Capt Graham Chapman for letting me purloin a section of his daily POSREP.
Diary 08 may be written by Sunday 25th depending upon my relief.
Next week we have a new member joining the fold.Javed Ansari/ETO Comms,will take over from me and may be persuaded to take up the reins of Web-editor.