# Floating Oil Storage Vessels



## chadburn

I watched a programme in regards to a Tanker which had been converted to a Floating Tank Farm, she had made her own way round to Brazil and when she was plugged in offshore the Master turned over the vessel to the Tank Farm Boss as she was no longer a vessel. The question I ask is what happens to the Main Engine after it is shutdown, is it ever run again, is the fuel and propshaft permanently disconnected? Thanking you in anticipation.


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## McCloggie

It depends Chadburn.

If the tanker has to be dis-connectable for, say, South China Sea or Gulf of Mexico then all ship systems will be kept and the ship can use the main propulsion plant as required.

My present job will entail sailing the tanker under own power from Singapore to North West Europe where we will go into dry dock, take off the propeller, pull the shaft and tow the ship to the North Sea Field where she will stay for at least 8 years.

It really depends on where the Field location is, length of Contract, the need to dis-connect in severe weather etc. Also, you need to consider what the "main engines" are used for. On one job the MEs were actually generators, providing electrical power to thrusters and to two conventional CP props.

There is really no hard and fast rule here. Client demands come into play as do the well characteristics - can you use off-gas from the process plant for power, do you burn crude or do you load MGO on a regular basis. It depends on the Contract.

In the North Sea, the norm is to keep the ship on station but my experience is that if she can be dis-connected and sailed to a yard when required, this will be cheaper than having a static, non-dis-connectable mooring system.

As I said, it really depends on location, length of Contract and Client demands.

McC


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## chadburn

Thanks McC. the tanker/ storage platform concerned was off the coast of Brazil and it took crude from two rigs, stored it and piped it to a Tanker when required, I gained the impression rightly? or wrongly? that the M/E would never be used again which seemed a waste. She was a former Mearsk Tanker which had been converted in Singapore if I remember correctly.


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## McCloggie

Sounds like my last job - the Peregrino FPSO.

Yes, you are correct. We took new-build Maersk Tankers ship (Maersk Nova I think) sailed her to Kepple in Singapore, did the conversion, sailed her to Brazil under own power and then decommissioned the ME.

You must remember that if the ME is still going to be used then it needs to be maintained, run etc. and this of course needs qualified people, maintenance etc. 

It really is the cheaper option to simply properly decommission the ME and leave it in place. Believe me, it is common practice!

McC


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## McCloggie

Peregrino was not just storage, she is a production unit as well! Check my gallery for photographs.

McC


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## chadburn

McCloggie said:


> Sounds like my last job - the Peregrino FPSO.
> 
> Yes, you are correct. We took new-build Maersk Tankers ship (Maersk Nova I think) sailed her to Kepple in Singapore, did the conversion, sailed her to Brazil under own power and then decommissioned the ME.
> 
> You must remember that if the ME is still going to be used then it needs to be maintained, run etc. and this of course needs qualified people, maintenance etc.
> 
> It really is the cheaper option to simply properly decommission the ME and leave it in place. Believe me, it is common practice!
> 
> McC


Thanks McC, That was the name of the vessel now that I remember, you have touched on my question, when you say decommision what exactly does that entail, is the intermediate prop shaft removed and set aside, tail shaft clamped as it is now legally? an installation rather than a ship. I laid up two vessels but that was a straight forward standing down (although decommision could be the right word as they both had armouries on board) until the legal ownership was decided. The transition from ship to installation seems to be a lot more involved to comply with legal requirements?. I left the M.N. in 1981, this is all new information for me. Regards Chad.


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## McCloggie

Firstly, yes, there is a difference between an "installation" and a "vessel" but this is mostly to do with Regulatory Compliance - ATEX regulations for example do not apply to a vessel but do for an installation and IMO/SOLAS regulations apply to a vessel but not an installation. So, you can have one tanker with different requirements - a veritable nightmare!

Again, the level of decommissioning will differ from case to case. On the present job we will remove the rudder and prop (as we are installing a stern thruster and they will effect the thruster operation) and pull the tail shaft. On Peregrino, the decommissioning was done offshore and I think they locked the shaft and rudder.

We also consider the age and state of the ship systems - will any be used when the ship is an installation and if so do we need to replace/upgrade (say cables) or will we put in a new system and get an exemption for a single voyage. Space is an other consideration - will a thruster motor fit in the engine room as it is or do we remove existing equipment etc.

In short, there is no hard and fast rule and virtually all the jobs I have done have all been different.

McC


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## Satanic Mechanic

chadburn said:


> I watched a programme in regards to a Tanker which had been converted to a Floating Tank Farm, she had made her own way round to Brazil and when she was plugged in offshore the Master turned over the vessel to the Tank Farm Boss as she was no longer a vessel. The question I ask is what happens to the Main Engine after it is shutdown, is it ever run again, is the fuel and propshaft permanently disconnected? Thanking you in anticipation.



Actually doing a conversion right now.

As McC says there are a few combinations, in our case we will use the engine to get on station and basically forget about it, remove it from continuos survey. We will also install a stern tube seal that is designed for stationary shafting using grease


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## chadburn

Thanks for the further info(Thumb).


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## Satanic Mechanic

I have the latest MAN guidelines for laying up engines if your interested


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## chadburn

Thanks for the offer, I think others on the site will also be interested on todays measures for laying up engines, although I gather that it is unlikely the Peregrino's engine will be run again. The way the Worlds weather is changing I would have liked an engine that could be used in an emergency if the Tugs could not attend. Has a new FPSO Boss a Marine Engineering background or Petro Chems?


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## McCloggie

Again, it all depends on the job Chadburn.

Bluewater's dis-connectable FPSO Munin had a Master/OIM who was a fully qualified MN Captain. We then had a Technical Manager (Chief Engineer) and a Production Manager for the topsides. Maersk's FPSO in Australia had an OIM and the Marine Supervisor assumed the role of Master if the ship had to dis-connect. 

For Peregrino, the Offshore Installation Manager (OIM) who took over from the passage Master happened to be ex-Maersk Tankers and was Master qualified but that was more by luck than anything else.

I know OIMs who came from the Safety side of things and were neither MN Master nor CE!

You have to remember that an FPSO is primarily regarded as an installation and will not normally move off location so the STCW rules do not normally apply. Consequently, the Superintendents offshore may well have a marine background, but he OIM ma often come from a different, management, background.

The onshore guys though are the ones with the real experience.

McC



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## chadburn

Thanks McC, I did hear the OIM say when he took over from the Master that he had sailed with the Master years before, he did not say as to whether he was Engineering or Deck as far as I remember which led me to the question. Although on reflection the hint was there as the handing over Master would not have given his gold to an Engineer!!!


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