World's OFFSHORE VESSELS

[pilotdane]

Have legs ever become stuck in the soil? I assume the vibration of work, weather and waves could cause legs to settle into the soil. I'm curious if they can become so stuck that the barge does not have enough bouyancy to pull them free? I assume you could use a water jet or something similar to excavate and help break the suction.

[ombugge]

Have legs ever become stuck in the soil? I assume the vibration of work, weather and waves could cause legs to settle into the soil. I'm curious if they can become so stuck that the barge does not have enough buoyancy to pull them free? I assume you could use a water jet or something similar to excavate and help break the suction.

Ah, you have put your finger on another problem with jack-up rigs, especially of the 3-legged kind. You must have read up on Jack-up rigs, or have some knowledge of the beasts?

Yes, legs do get stuck at times and it can take a long time to get them free. but first to your next item.

To avoid that the legs penetrate further during drilling operation it is necessary to simulate the the worst possible load the legs can be exposed to during the stay at the specific drilling location. This is done by adding ballast, known as Preloading. Some of the newer rigs is able to jack with full preload on board and are less prone to damages, but most are not.

The way the weight on legs are obtained is to raise the hull above water, take on ballast to predetermined weight per leg and hold for one hour to test the soil bearing strength.

Unfortunately, sometime the legs settles as you add on weight and the hull gets in the water again. (The hull has to be kept level within 0.3 degr.)
Solution; dump back the preload until within allowable jacking weight, raise the hull and do it again.

This is repeated as many times as it takes to reach firm soil. I have done 8-9 such operations and reached a penetration of 120-130 ft. This could take a couple of days. In this process RPD may develop passed acceptable limits (See earlier posts) In that case the legs may have to be freed and the whole process starts all over again. Tedious, but also dangerous.

If the Airgap is too high and the penetration happens too rapidly (always at a single leg, not together) we get what is know as a "Punch through". That is what happens to the rig in the post above, and is a constant treat in soft soil with hard layers in between.

There are several mitigating methods, but that would be too lengthy to explain here. One method is called "Swiss Cheese" by the way. (Now, use your imagination)

Now for freeing the legs again; As you rightly said, there are indeed a water jetting system for this job. The hull is lowered back down in the water and pulled down above the floating draft to create excess buoyancy. Water is pumped down and ejected through nozzles at the bottom of the Spud Cans (Footing).

In theory this should break the suction and the legs can be raised gradually above seabed. It doesn't always happen like that. Usually one legs breaks loose first and you loose some of the upward pull on the remaining legs.

There are as many theories about the best way to do this as there are Rig Movers in the world. The longest I can remember having spent freeing legs is 3.5 days. The record is said to be 21 day on a functioning rig, mainly because of lack of knowledge and experience by the people on board.

With 4-legged Jack-ups the process is much simpler, faster and safer, but for some reason nobody is going for those as Drilling Rigs anymore. I have a concept ready, if anybody is interested.

[Clipper]

I have a concept ready, if anybody is interested.

I, for one, am fascinated but don't have the funding to qualify me as "interested".

Clipper

[ombugge]

There was a lengthy debate on another thread about UT 704s built at Sterkoder Yard. Here is one of the posts by Sterkoder:

UT704 built by Sterkoder, status today as far as I know:

"Majestic Tide" is still in service, with Tidewater Hulls Ltd.
"Mighty Tide" is still in service, with Tidewater Marine Intl Inc-Sng.
"Master Tide" is still in service, with Tidewater Marine Intl Inc-Sng.
"Brute Tide" is still in service, with Tidewater Hulls Ltd.
"OSA Vigilant" (ex. "Active Queen" ) is still in service, with Tidewater Marine Australia
"Cosl 671" (ex. "Atlantic Blåna" ) is still in service, with China Oilfield Services Ltd.
"Cosl 672" (ex. "Atlantic Vest" ) is still in service, with China Oilfield Services Ltd.
"Lutoga" (ex. "Lyutoga" ) is still in service, with Caspian Sea Oil Fleet

Can't come up with other UT704s built by Sterkoder, as I belive this was the lot

By coinsident I was working with one of the vessel, the Mighty Tide, this last week during seatrails off Karimun Island, Indonesia.
This one has never changed name or ownership since new and appears to be very much the same as when she left the yard some 27 years ago. Still going strong, as is her sister ship of this same design, including the first one, built in 1975/76.

Here she is, towing the newbuilt Pipelaying/Accommodation Barge "AZIZ" out from Jurong West Anchorage, Singapore:


A bit closer view from Stbd. side:


From Port side:

This is a bit blurry since it was taken from a bucking launch.

From the stern:


Some more details for those who like that:








Heading into the sunset, towards Malacca Strait with the Aziz in tow:


I also have some "action pictures" of the Mighty Tide handling anchors, but that will have to wait for another post.

[Sterkoder]

Thank you so much for those pictures, 'ombugge'!!!!
What's the story about different IMO-numbers on the "Mighty Tide"??
One nr. on the side of the bridge house and one different on the side of the hull, above the plimsol mark.

[janihudi]

the two one's are standing very close to each other on the bridge,sterkoder and are also of another type

811 on the hull and 8ll on the bridge, they stand closer

[Sterkoder]

the two one's are standing very close to each other on the bridge,sterkoder and are also of another type

811 on the hull and 8ll on the bridge, they stand closer

So embarrassing for a guy like me, enjoying details....
I must admit, I thought the bridge wall IMO-nr. started with 88, but now I see they are totally alike....

[Steve.B]

Very interesting photos Ombugge, very much appreciate you posting them. So often i am guilty of enjoying looking at the photos people post and do not post a thank you, but i guess a lot of posts just saying thank you would get monotonous. But, just so all of our image posters know, i do greatly appreciate the time and trouble that you go to!

[janihudi]

I must admit, I thought the bridge wall IMO-nr. started with 88, but now I see they are totally alike....

same here sterkoder i also tought that the second 8 was missing something,but i have'd look at the hull

[ombugge]

To finish off the postings about Mighty Tide, here she is handling anchors for the AWB Aziz during sea trail off Karimun Island, Indonesia. Not much "action" as this is in inshore waters and dead flat calm.

Mighty Tide alongside Aziz to receive Anchor, Buoy and Pennant wire:







Some of the Iban Riggers from Aziz is assisting the crew of M.T. hence so many people on deck.

Anchor secured on deck and ready to run:


Pulling the anchor off deck:


Anchor wire paid out to full length of 1400 m.:

Ready to set the anchor on bottom and "splash" the Buoy.

Moving in to get the next anchor wire:


Wire connected, lining up to run out:

This one without an anchor, as we were testing winches only.

Sea trial completed. Heading back to Singapore. Crossing the East bound Traffic Separation Zone in the very early morning:

[pakarang]

Very interesting to see how the operation is done: slightly more preparations to lay out the anchor, as opposed to "normal" ships. Precision work indeed.

[Clipper]

By heck, they even find time for some fishing.

Clipper

[ombugge]

By heck, they even find time for some fishing.

Clipper

No, they are ready to catch the heaving line from the barge.

[ombugge]

For all you "details freaks" let me present the newbuilt AWB "AZIZ", built in China in 2009 with additional equipment installed in Singapore.
The barge is still not entirely ready, with some of the pipelaying equipment and a 500 m.t. SWL crane yet to be installed, but it was rushed out for a job that doesn't involve pipe laying or heavy lifting. Here she is.

View of Stbd side with Pipelay Bay (Firing Line):

Leaving Singapore for Sea Trails

View of Port side :

Returning to Singapore after Sea Trails.

View of Stern with Stinger Support A-Frame and mobile Saturation Diving Spread:


Closer look along Port side w/ Pipe Handling Davits and Air Diving Spread:


Boat Landing on Port side w/ "Swing Rope" to assist in safe boarding:


View of the Work Deck w/2 Crawler Cranes, 75 and 50 m.t. SWL respectively:


View along top of Firing Line on Stbd. side:


Helideck as seen from top of Accommodation Block:


Helideck Fire Fighting System being tested:


More to follow.

[ombugge]

The living conditions on this barge is quite good relative to some of the AWBs coming out of China.

Here is a typical 2-men room for Supervisory personnel:

There are also some 1-men room for Senior personnel, like Barge Superintendent, Client Representative etc.

4-men room (large):


4-men room for workers:

All rooms have attached bathrooms, some shared between two rooms.

Messroom for crew and workers:

There is a separate Messroom for Senior personnel, but not in use at this time.

TV Room. Also used for Safety Briefing etc.:

There are also Recreation Rooms, Prayer Rooms and a Gymnasium.

Communication Dome on top of Accommodation Block:


Radio Room:

Which also holds navigation equipment, such as Radar, Echo Sounder, Compass etc. (Not much of a view from here)

The Aziz has 12 x 25-men life rafts with space for 300 pers. placed 4 x 3 on either side:

Total 24 rafts + 1 spare on board. (Total capacity; 600 pers., or 200% coverage)

Muster Station on either side at 1st Level:

The yellow "boxes" are for easy identification, and who goes in which raft.

More to follow.

[ombugge]

In the Generator Room there are 6 generator sets, 800 kWe each:


Top of the Exhaust duct is covered by spark arrestor net to avoid any sparks flying in the air when working alongside active Oil and Gas Platforms:


There are 2 Reversed Osmosis Water makers, each able to produce 50 Cbm/day of drinking water from seawater:


Working in the tropics it is important to keep the Living Quarters cool. There are 2 Air-conditioning Compressors:

They are new, although not of the most modern type.

The ballast system is also rather "primitive":

All manual operation. No "sophistication" here.

The Aziz is a dumb barge (non-propelled) and has to be towed between locations.
Here the main tow bridle are being recovered:


Tow connections are Smit brackets type, rated for 100 m.t. SWL:


When in operation the Aziz is held in position, or moved along while laying pipe, by means of a 8-point mooring system.
Here is one of the 8 x 70 t. Mooring winches place below deck:


And a Fairlead at the edge of the barge:


One of the 8 x 12 m.t. Delta Flipper type High Holding Power (HHP) Anchors:


More to follow

[G. of S. Florida]

Ombugge, many thanks for the photos of the Mighty Tide and the work she was doing. Most interesting. One thing that I noticed was that on her port and starboard sides, near the stern, she had her name, Mighty Tide with Port Vila just below it. I immediately thought of the QE2. After she arrived at Dubai they painted over Southhampton and put Port Vila in its place. Can you or someone else advise as to where this Port Vila is. Again thanks for the photos.

[ombugge]

The Mooring winches are remotely controlled from the Anchor Control Tower, which is situated on top of the Accommodation Block and under the Helideck.

Here is the Control Panels for the 8 Mooring winches, each with a computer screen showing all necessary data and CCTV screen showing the winch:


Also in the Tower is the Pipe Tension and A/R Winch Controls:


For the upcoming job in Burma the Aziz has 5 x 30 m.t. SWL Pipe Handling Davits installed along Port side:


She also carries mobile 6-men Saturation Diving Spread, rated for 200 m. Water Depth.
Here is the Diving Bell and Launch/Recovery A-frame:


The living and de-compression Chamber:


In case things should go wrong and the barge has to be abandoned while divers are still in saturation there is a Rescue Chamber, which can be jettisoned, or will float up if the barge should sink:


Clear instruction to anyone "finding" the Rescue Chamber:


There is also an Air Diving Spread for use in shallow water (Less than 50 m.):


More to follow.

[ombugge]

The Pipe Laying equipment is only partly installed. Welding, doping and X-ray stations are still not in place, only Tensioners and Rollers. No Stinger is carried.
Pipelaying is not required for the upcoming job in Burma, however.

Here is the after most roller guide in the lay bay. The height can be hydraulically adjusted:

From here the pipe goes onto the stinger, which has adjustable rollers to create the right curvature of the pipe, depending on water depth.

2 x 40 m.t. Tensioners, able of handling pipe with 60" (152 cm.) OD in water depth up to 100 m. or more:


Here is a closer look at one of the tensioners:


A look along the Firing Line, looking Fwrd.:


Pipe Transfer arrangement, looking Fwrd.:

Rollers on the left is feeding pipes from the deck outside. On the right is the Firing Line.

Pipe Transfer arrangement, looking aft:


Line-up table:

Move the pipe from the feed line to the firing line.

Details of the transport rollers:


Transfer and line-up Control panel:


Overhead cranes:


Hope this satisfies the curiosity of even the the biggest "detail freaks".

[ombugge]

Ombugge, many thanks for the photos of the Mighty Tide and the work she was doing. Most interesting. One thing that I noticed was that on her port and starboard sides, near the stern, she had her name, Mighty Tide with Port Vila just below it. I immediately thought of the QE2. After she arrived at Dubai they painted over Southhampton and put Port Vila in its place. Can you or someone else advise as to where this Port Vila is. Again thanks for the photos.

Port Vila is Situated on the island of Espirito Santos in the South Pacific. Capital of Vanuatu. (Formerly New Hebrides)

Used to be jointly administered by Britain and France, in a "Condominium (as opposed to a Colony) but now an independent nation.

Popular "Flag of Convenience", especially among American Owners since the registry is actually controlled from the US.

Famous as the place where Bungee jumping was invented.