World's OFFSHORE VESSELS

[janihudi]

Drove around to try out some settings on my camera in the bright sunny day we have here in Kristiansund today.
The difference in these images from the blury first one, is that I'm moving away from the 'Auto' in some cases, and I set
the ISO to 64. I also got out of my car to prevent pictures being taken through heatwaves from my car cabin.
Hopefully these images are at least a bit better than the earlier ones.
"Skandi Captain" at Devoldholmen

was´t it better to take al lot of this ship photo`s in differnd set up`s,so you can see what the differnd of settings do.
i mean when you take photo´s of differend objects with differend set up´s
you don`t now how much the settings wil ingrease?? your photo

[Sterkoder]

Thanks for your tips, but "Skandi Captain" at that position at Devoldholmen.....: I got hundreds of images

[pakarang]

Don't you agree with me thinking that 5,8 millions is a bit stiff of a price for an old rescue vessel?

Are the walls gold-plated maybe?

[Sterkoder]

Don't know about the money, but anyway...., here are some pictures from the interior
http://www.finn.no/finn/boat/object?finnkode=20730667

[pakarang]

Don't know about the money, but anyway...., here are some pictures from the interior
http://www.finn.no/finn/boat/object?finnkode=20730667

Not bad at all... Me like!

[ombugge]

("Hagbart Waage" for sale, if you got NOK 5,8 millions)

What's all the pennants for???

[ombugge]

Pardon my ... ehhh.. Italian, but that newbuilt El Quaher is butt ugly...

Here is updated pics of El Qaher 1 taken two days ago, now raised to install top leg sections:


Looks a bit better with the legs in their correct place:


Getting ready to climb to the top of the legs for Jacking Test.
Good view from up there, especially standing on the Helideck:


The skid beams cantilevered over the sides will be removed when she gets down close to water again:


Still butt ugly, but at least a little better than in the earlier pics of a week ago?:

[pakarang]

WHat a peculiar and very strange looking.... ehhh.. contraption!

[ombugge]

WHat a peculiar and very strange looking.... ehhh.. contraption!

This is a fairly standard Jack-up rig, (Self-elevating Mobile Drilling Unit) capable of operating in 375 ft. (114 m.) of water.
There are abt. 450 such units in existence and used world wide. You must have seen many during your years at sea?

The major difference is that here there is not much water depth here. When they get up to the top of the legs during Jacking Test the "Air Gap" (Dist. from bottom of the hull to the water surface) will be something like 100 m. Not very good if you suffer from vertigo.

As mentioned in an earlier post, the Helideck will be at abt. the same height above water as "Fjellstua" in Aalesund. It would make some nice pictures, if the test was done at Skansekaia in Aalesund, don't you think?

I'm due to go back out there tomorrow, or day after. If they are up on top of the legs then I'll get some good shots, I hope.

[pakarang]

I guess it is a strange sight to me, as I have never seen something like this with my own eyes.

Wold like to have this option for some pretty cool aerial shots many a time, but I guess a helicopter would do the same job for me...

[ombugge]

I guess it is a strange sight to me, as I have never seen something like this with my own eyes.

Wold like to have this option for some pretty cool aerial shots many a time, but I guess a helicopter would do the same job for me...

At least it would be FASTER. Jacking speed is 1.5 ft/min.

[pakarang]

At least it would be FASTER. Jacking speed is 1.5 ft/min.

That is actually quite a bit faster than I had expected.

[Clipper]

At least it would be FASTER. Jacking speed is 1.5 ft/min.

How interesting, Ombugge. What type of jacking mechanism is employed?

Clipper

[Tom McNikon]

Far Scorpion in Bergen today

[ombugge]

How interesting, Ombugge. What type of jacking mechanism is employed?

Clipper

Rack and pinions. Four pinons per jacking frame, three frames per leg, for a total of 36 electric motors and gears.

Here is specifications for the jacking system on this PPL Pacific 375 type:
Jacking System
Number of pinions 36
Number of jacking motors 36
Normal jacking load 43,560 kips
Preload jacking load 58,608 kips
Jacking speed 0.36 m/min
Load monitoring
Rack Phase Differential monitoring
Local and remote control
(FYI 1 m.t. = 2.205 Kips)

If you look back in this thread you will find some closer looks at the jacking system on another of these rigs, incl. the Jacking Control Panel.

The "El Qaher I" had come down close to water again today:

Obviously without completing a jacking test to the top of legs, since the scaffolding is still in place up high.

Here is a pics taken from PPL Web site showing another rig way up there:

[Clipper]

Rack and pinions. Four pinons per jacking frame, three frames per leg, for a total of 36 electric motors and gears.

Here is specifications for the jacking system on this PPL Pacific 375 type:
Jacking System
Number of pinions 36
Number of jacking motors 36
Normal jacking load 43,560 kips
Preload jacking load 58,608 kips
Jacking speed 0.36 m/min
Load monitoring
Rack Phase Differential monitoring
Local and remote control
(FYI 1 m.t. = 2.205 Kips)

Fantastic detail Ombugge, thank you. The trouble though, is that I now have more questions

• Are the jacking loads "per motor"?
• Do all 36 motors work together or does it jack one stage (ie. one frame on each leg) at a time?
• Differential monitoring is the really interesting part for me. Do you know any more detail? For example what type of sensors are used? Is there any redundancy?
• How are the frames locked together at their end of travel?
• I'm wondering about the corrosive effects of seawater and the need to reverse the jacking operation to eventually recover the platform. Do the motors and/or racks need to be removed from each frame as it passes through the platform?

Thanks in advance

Clipper

[ombugge]

Let me try to answer the questions you are asking one by one and in simple terms.

The "Jacking Loads" given here is total load. Pinion load; J.L./36

This is a 3-legged independent leg rig. I.e. you can operate any one leg different from the other. This is mostly done in order to keep the hull level when the legs penetrate the soil differently. All jacking motors on one leg work together, however.

Rack Phase Differential (RPD) is a very complex subject and was not really recognized and understood until some 15 - 20 years ago, after severe leg damages was experienced on some of the newer rigs with high tensile steel legs.

This has to do with the load per leg cord becoming different due to uneven torque on the motors, which cause the leg braising to be at different levels by a few mm. in the horizontal plan, which again causes uneven loading of each cord in the leg. Uneven soil strength under each cords may also contribute to this situation.

On these new rigs it is possible to measure RPD continuously by electronic means, and to equalize the torque by operating one cord alone for a very short time.

Earlier, we just listened to the noice. If it became uncomfortable to the ears we measured the RPD manually and tried to adjust the level of the hull to ease the friction.

The Jack Frames are fixed to the hull while the racks are fixed to the legs, which moves freely through guides in the hull. Jacking is thus a continuous process. Jacking speed is the same, up or down and regardless of weight.

Some rigs has hydraulic jacking system, where "stroke length" of the cylinders goverened. You have to stop and recycle frequently, but that is a different type of rigs and a different story.

As for corrosive effect, it is not a problem as long as the motors and gears are weather proof. Ample grease protect the rack teeths from corrosion

Moving these contraptions between drilling locations is also a different story. It require special knowledge of soil conditions and loads to foresee how the legs will penetrate the soil.

If it is not done right you get what is known as "rapid penetration", which can end up becoming "punch through", when the legs and jacking system can be badly damaged, or legs sometimes have been broken off and come crushing down on the rig, like here:




This particular design was the first to get electronic Rack Face Differential detection and correction system installed, some 15 years ago.

I have moved this rig and her 4 sisters many times without any major problems after that. Many hairy experiences on other rigs with high tensile steel legs of that same early 1980 generations, built with a life expectancy of 15 year and still around 30 years later.

[Clipper]

Let me try to answer the questions you are asking one by one and in simple terms.

The "Jacking Loads" given here is total load. Pinion load; J.L./36

This is a 3-legged independent leg rig. I.e. you can operate any one leg different from the other. This is mostly done in order to keep the hull level when the legs penetrate the soil differently. All jacking motors on one leg work together, however.

Rack Phase Differential (RPD) is a very complex subject and was not really recognized and understood until some 15 - 20 years ago, after severe leg damages was experienced on some of the newer rigs with high tensile steel legs.

This has to do with the load per leg cord becoming different due to uneven torque on the motors, which cause the leg braising to be at different levels by a few mm. in the horizontal plan, which again causes uneven loading of each cord in the leg. Uneven soil strength under each cords may also contribute to this situation.

On these new rigs it is possible to measure RPD continuously by electronic means, and to equalize the torque by operating one cord alone for a very short time.

Earlier, we just listened to the noice. If it became uncomfortable to the ears we measured the RPD manually and tried to adjust the level of the hull to ease the friction.

The Jack Frames are fixed to the hull while the racks are fixed to the legs, which moves freely through guides in the hull. Jacking is thus a continuous process. Jacking speed is the same, up or down and regardless of weight.

Some rigs has hydraulic jacking system, where "stroke length" of the cylinders goverened. You have to stop and recycle frequently, but that is a different type of rigs and a different story.

As for corrosive effect, it is not a problem as long as the motors and gears are weather proof. Ample grease protect the rack teeths from corrosion

Moving these contraptions between drilling locations is also a different story. It require special knowledge of soil conditions and loads to foresee how the legs will penetrate the soil.

If it is not done right you get what is known as "rapid penetration", which can end up becoming "punch through", when the legs and jacking system can be badly damaged, or legs sometimes have been broken off and come crushing down on the rig, like here: [IMG] [IMG]

This particular design was the first to get electronic Rack Face Differential detection and correction system installed, some 15 years ago.

I have moved this rig and her 4 sisters many times without any major problems after that. Many hairy experiences on other rigs with high tensile steel legs of that same early 1980 generations, built with a life expectancy of 15 year and still around 30 years later.

Thank you Ombugge, you clearly have a very interesting job. I understand a lot better now, in particular that the Jack Frames are fixed to the hull.

I also found this document, which seems to describe the same/similar jacking system and adds further to my understanding, though I confess that some aspects remain a complete mystery because not all the specialised terms are explained.

Never mind, I will learn more one day if I get a job in the oil industry

Thank you again Ombugge for your time spent answering my questions.

Clipper

[ombugge]

Thank you Ombugge, you clearly have a very interesting job. I understand a lot better now, in particular that the Jack Frames are fixed to the hull.

I also found this document, which seems to describe the same/similar jacking system and adds further to my understanding, though I confess that some aspects remain a complete mystery because not all the specialised terms are explained.

Never mind, I will learn more one day if I get a job in the oil industry

Thank you again Ombugge for your time spent answering my questions.

Clipper

The RPD was pretty well explained in the Noble article, which describes a different design to the PPL P-375. The jacking system is also slightly different in as much as there are only one rack per cord and the pinions are in line, not on opposit sides of the cords.

RPD is a very complex subject and not easy to understand, unless you are directly involved, like I was when the first RPD monitoring and correction system was installed and commissioned on the rig type you see with the broken leg in my earlier post. (No longer belonging to Maersk at that time)

By the way, I'm no longer doing Rig Moving, nor going Offshore very often. 35 years of it was enough. I'm dealing with simpler and less stressful things these days.

[Clipper]

Ombugge,

Having done my training with Honeywell in the 1970s, instrumentation and control systems have always been a source of great interest to me. The general principles are always the same but the details always differ from application to application.

I'm dealing with simpler and less stressful things these days.

"less stressful" - a good choice of words given the subject matter.

Thanks again

Clipper