Same shit, different ship

[DrWilly]

MalbecMike onnit again.

[dirk diggler]

I’ve smashed the fk out if 3 CP probes already on this job.

I’d considered mentioning Catholic Protection and Sacrificial Anodes in this thread…

… but it’s so fucking dull and boring that I was hoping you would bring it up and explain it.

So don’t stop there, you were doing so well!

[DrWilly]

I understand sacrificial anodes but not sure what catholic protection is… though I’m guessing some sort of cap or covering (like a condom) to completely seal the metal inside.

[dirk diggler]

Here’s a pic of a CP probe resting on a zinc block in a bucket of sea water to get things started.

[Mendip]

^ I'm on it.

[Molle]

not sure what catholic protection is

[dirk diggler]

ChatGP says…

Subsea assets, such as vessels, pipelines, manifolds, risers, and wellheads, are typically made from steel, which is highly susceptible to corrosion in the marine environment. To mitigate this, cathodic protection (CP) is applied, and anodes play a key role in this system.

Subsea anodes are used as part of a cathodic protection system, which protects metal structures from corrosion in seawater.


➤ How it works:
• Seawater is highly conductive, which accelerates the electrochemical corrosion process.
• To prevent corrosion, sacrificial anodes (commonly made of zinc, aluminum, or magnesium) are attached to the asset.
• These anodes are more reactive (have a lower electrochemical potential) than the steel asset.
• As a result, the anodes corrode (or “sacrifice� themselves) instead of the steel, hence the term “sacrificial anodes.�
• This creates a galvanic cell where the anode corrodes and provides electrons to the steel, keeping it cathodic (negatively charged) and thus protected from corrosion.


An alternative to sacrificial anodes is impressed current cathodic protection (ICCP), where a DC power source is used with inert anodes, but sacrificial anodes are more common for subsea structures due to simplicity and reliability.



During subsea inspections, ROV (Remotely Operated Vehicle) crews take Cathodic Protection (CP) readings to monitor the effectiveness of the CP system and ensure the structure is still protected.


➤ CP readings are taken for the following reasons:
1. Verify protection level:
• A properly protected steel surface should have a potential more negative than -0.800 V vs. a silver/silver chloride (Ag/AgCl) reference electrode in seawater.
• If the potential is less negative (e.g., -0.700 V), the structure might be underprotected and at risk of corrosion.
2. Assess anode performance:
• Over time, sacrificial anodes deplete. CP readings help determine if the anodes are still active or need replacement.
• CP readings can indicate if anodes are no longer electrically connected due to damage or poor installation.
3. Monitor coating damage:
• Subsea assets often have protective coatings. If the coating is damaged, the steel is exposed and CP demand increases.
• Localized drops in CP potential can suggest coating failures or high corrosion activity.
4. Support integrity management and maintenance planning:
• Helps asset owners make informed decisions about life extension, anode retrofit programs, or further inspection.
• Part of compliance with industry regulations and best practices (e.g., DNV, NACE, ISO standards).

ROVs use CP probes (typically contact or proximity probes) connected to a reference electrode. The ROV pilot maneuvers the probe to touch or come near the asset to measure the potential between the asset and the reference cell. The values are recorded and compared against baseline data or acceptance criteria.

[Mendip]

but not sure what catholic protection is… though I’m guessing some sort of cap or covering (like a condom) to completely seal the metal inside.

Guess again.

Cathodic protection is what prevents steel pipelines and structures corroding in the marine environment.

I'm not sure I like Dirk's AI stuff. I don't really like this AI thing much at all to be honest, I think it's the thin end of the wedge and best avoided.

This is more like it.



Basically Zinc/Magnesium etc sacrificial anodes are installed on a pipeline at regular distances to protect it against corrosion. The more reactive (less Noble) anode, sacrificially corrodes which maintains an electron flow into the steel pipeline, thus protecting it from corrosion. We check anodes for visual signs of activity, electronic connection to the steel of the pipeline and occasionally measure their CP (cathodic potential) to ensure adequate protection is being provided. The level of protection will decrease with age due to consumption by corrosion of the anodes. A value of around -1100 to -1200 mV is good for anodes. If we can find exposed bare metal on a pipeline we may also take a measurement on that, when values of around -800 to -900mV indicate protected steel.

It's not as simple as just installing a load of anodes on a pipeline during fabrication of course... a by-product of the anodes oxidising is hydrogen, and an over-abundance of anodes my cause hydrogen embrittlement of the steel pipeline which can cause considerable weakness. Protection against corrosion is a whole industry on its own and Dirk may find it

fucking dull and boring

but I find it quite interesting.

But not as interesting as rocks, or course.

Tomorrow I will find a few pictures of pipeline anodes, I promise. But in the meantime...

The CP probe mounted on the ROV.



We were also measuring the continuous cathodic potential of a buried pipeline, hence the pipetracker frame (black and blue). The pipetracker collects depth of burial measurements and also we attach the continuous CP equipment to the pipetracker frame to continuously measure the field gradient given off by the pipeline along its length. The field gradient measurements are (ideally) calibrated by the occasional CP stab on an anode if we can get one, but impossible on a buried pipeline.

To be honest, I think that measuring the electronic potential given off by a buried subsea pipeline with a corrosion coat and a concrete weightcoat, by an ROV riddled with electronics and hydraulics, is a load of mumbo jumbo. But companies seem to make a living out of it...

A photo-bombing havmus (Norwegian rabbit fish) and ling. An unlikely pair.



And as Dirk will tell you, a pretty pointless CP stab being taken on the concrete coating of a pipeline. You need to contact bare metal to get any meaningful results.




Today we were working close to the Tyrihans field semi-sub platform, which I think was off our port side...



But it was foggy so I can't be sure. It may have been off the stern...



Or maybe off our bow?

Fukked if I know.




My shifts have picked up a bit since the last crew change. I have always accepted that training staff trainees is part of the job, even though I am basically training meself out of a job.

But, I have always drawn the line at training freelancers who should know the job and who I am in direct competition with for work.

Unless they are pretty.

I've spent a lot of time helping out the new Brazilian freelancer and today when she finished her shift she said to me in her husky Portuguese accent,

'Mendip, there is a special place in heaven reserved for you'

This cheered me up no end. I don't think I've ever had a compliment like that before... ever.

Although if she could have read my mind during the shift I don't think she would have been quite so complimentary.

And not only that, yesterday my favourite Norwegian trainee plated up the 6pm Saturday evening steak meal for me to eat for my own evening meal at 6am.

Un-asked!

This made a lovely change from tinned mackerel and salad.

It was a big meal... I think she's trying to fatten me up!

[malmomike77]

'Mendip, there is a special place in heaven reserved for you'

This cheered me up no end. I don't think I've ever had a compliment like that before... ever.

Hmm perhaps she's suggesting her competition is going to arrive there .....

[hallelujah]

Although if she could have read my mind during the shift I don't think she would have been quite so complimentary.

Were you wondering what Yogi would look like dressed up in her knickers AGAIN?

[Mendip]

^ What a strange comment, I'm not some kind of weirdo.

I dress up Anna in lingerie... never Yogi, he's a boy.


Yesterday we finished up the Tyrihans project with a 40km gas export pipeline to the Asgard B semi-sub platform. This enables connection to the Asgard Transport Pipeline, a 720km long gas export pipeline to the gas terminal near Stavanger. From there, some of the gas will doubtless be exported to the UK and elsewhere around Europe.



There must be some extra works going on at Asgard B and we weren't allowed into the platform safety zone due to a Flotel (for extra accommodation) alongside the semi-sub. The anchor array would be a real problem to our ROV.



The nearby Asgard A FPSO, I'm sure Dirk would agree, another Muckle Brut.



Just to the right of the Asgard A FPSO, the flare at the Kristin Platform was just visible, around 20km away. Visibility wasn't great, and my phone camera even worse, or else the platform would have been easily visible on the horizon. Kristin also ties back to Asgard to enable its gas to enter the export pipeline to be transported south.



The Transocean Spitsbergen drill rig that we saw in Kristiansund was apparently at a Kristin satellite well, another 15km further on, well out of our field of view.

Completion of the Tyrihans project finished our work at Haltenbank, after which we began the two day transit oop norf to the Northern Cape. After an hour or so we passed Aker BP's Skarv FPSO with attendant safety boat. There was also a drill rig nearby... there really is a lot of activity in the Norwegian Sector at the moment.



There's also been a lot of activity at my meal times lately. My favourite trainee plated up a lamb shank for my 6am evening meal yesterday which was most welcome. These were my first sprouts for five weeks and I've 'put it out there' that I haven't had a portion of peas since I left Thailand. I am confident my trainee will sort this out. She really is an excellent pupil (although she did forget the gravy with the lamb shank).



We are now at 69 degrees north and well inside the Arctic Circle. The midnight sun would definitely be visible from here, if it wasn't so bladdy cloudy.



We passed Bodø around twelve hours ago, where Spurs recently beat Bodø/Glimt in the semi final of the Europa League cup before stuffing Man Utd in the final.



Just now we're passing the northern Lofoten Islands and will pass Tromsø during the night. Sadly we're too far offshore to see anything during this transit. The skipper must be in a hurry.

[taxexile]

with a mixed crew on these boats is there much "hanky panky", or in sailor speak "fucking", going on.

[Reg Dingle]

^ I dont think Achmed boarded this year

[Mendip]

^

^^ Sadly not in my cabin.

On my second ever trip, when I was young and vulnerable I was taken advantage of by an older and experienced Norwegian stewardess. Back in those days we had a lot more port calls and this ridiculous industry-wide zero tolerance toward alcohol was still a few years away. Things tended to happen.

I knew that I'd made a mistake when she started to bring me morning cups of tea to my cabin to get me up, and it taught me a valuable career-long lesson... there really is no escaping when stuck on a boat and it's better not to start anything.

Things do still happen of course but generally the guys are quite protective of the females onboard, and married guys 'having hanky panky' is quite frowned upon.

If the companies involved get wind of anything going on they will generally split the perpetrators up and assign them to different vessels.

I heard of a married with kids English surveyor who impregnated a Filipina stewardess, then wanted nothing to do with it, and the shipping company no longer allowed him to work on the boat. I think they did the right thing.

[taxexile]

Mendip

there really is no escaping when stuck on a boat and it's better not to start anything.

probably very sensible.

[Mendip]

^ To be honest it's not as though I have much say in the matter these days... I seem to be the same age as most of these girls parents.

I'll be happy with a portion of mushy peas with my meatballs for breakfast tomorrow.

[Joe 90]

On my second ever trip, when I was young and vulnerable I was taken advantage of by an older and experienced Norwegian stewardess.

I bet that's one in your wank bank

[Joe 90]

I'll be happy with a portion of mushy peas with my meatballs for breakfast tomorrow

How times change

[Mendip]

^ Yes, an eclectic wank bank indeed!

(and I have a bowl of peas waiting for me)


The north-west tip of mainland Europe. After two days of transit we have rounded the islands around the north-west tip and changed heading toward the east. We are at 70 degrees north, just under 71 degrees, but still no midnight sun. It's too cloudy.



The work starts at the Melkøya refinery, located on an island just next to Hammerfest when we survey a pipeline northwards into the Barents Sea.

In the meantime, while the ROV boys were elsewhere...



... I sneaked out into the hanger to get a few sneaky pics of the Survey ROV without my PPE on.

A lot of equipment is mounted on the ROV for these pipeline inspections.

The business end...



And the arse end.



And the obligatory selfie so the daughter can see her old man at work.

[DrWilly]

Wow, that ROV is a lot bigger than I realised. Some of the other pics with it dropping in and out of the water made it look like it was only a foot or two long. I can see now it’s more like 7 foot long.

[Mendip]

^ Try 5.5m x 2.5m x 2.2m (l x w x h).

[DrWilly]

That’s a muckle brut!

[Mendip]

^ Certainly is!

After two days of transit, yesterday we finally changed heading towards Hammerfest on the north coast of Norway. The weather was perfect for the transit so we made good time.



It's a bit bleak up here. For me, once you've seen one bare, rocky mountain you've seen them all. I much prefer the lush greens of the SE Asian jungles.



The Melkøya gas terminal was our destination. Melkøya is a small island just off Hammerfest and I reckon it must be the most northerly gas terminal in Europe, maybe even the world?

Melkøya is the Norwegian word for the island, Muolkkut is the Sami word. My trinee reckons that the Sami people look the same as Norwegians but are just 'different'. She couldn't really explain why.



Norwegians get tax breaks to work in this God-awful part of the world. I'm not sure that I could do it, but the great thing about visiting places such as this is that returning home to Korat doesn't seem so bad after all. And I'm starting to miss my dogs.

There's probably no passport office within a 1000km of this place either.



But anyway, we had some gas pipelines to survey.



After inspecting a couple of lines making landfall at the terminal, we started heading out to the north-west on a 160km gas export pipeline from the Snøhvit (Snow White) field. Once there we have a load of infield lines to survey which should take us up nicely to next week's crew change. My crew change.



Yesterday my trainee was quite excited... she had heard that I liked peas and had plated me up a meal... with a bowl of peas! What a nice gesture.

I was also quite excited about this... my last peas were in Korat over five weeks ago...

Until I saw the meal. Either I've upset her in some way of Chitty joined the catering crew at last port call.

Jaysus... a slice of meat loaf with a piece of pollack and some other stuff.

I think.

I hate to throw out food but there was nothing else for it, and into the waste food hole it went. I'm not used to throwing out any food at all at home. If the wife or then gardener refuse any leftovers, there's the dogs and then the chickens. There is quite a strict pecking order but everything gets used up and no food goes into the bin at home.



But losing this 'meal' was OK because I'd also put aside a beef curry at midnight for my 6am meal... and the peas had come out again with the curry!

Happy days!



I added the trainees bowl of peas and it was pea city... and I've been farting for over 24 hours straight. Peas don't usually have such an effect on me but I think after going cold turkey for five weeks, this portion was just a bit too big.

And the problem with working with females... I had to keep leaving the office to let rip... they have not only been loud but pretty pungent as well.



A lesson learnt.

And guess what this was?



Yep, the sun at the start of my midnight shift.



The Midnight Sun.

Beautiful, but I still couldn't live here.

[malmomike77]

Peas don't usually have such an effect on me but I think after going cold turkey for five weeks, this portion was just a bit too big.

its horrendous the impact lack of peas has on your gut biome

[DrWilly]

Which plate did you throw out? They both look equally bad.