# Possible Silly Question Regarding I.G.



## smithax (Jul 16, 2009)

I am trying to find a regulation that states that a loaded VLCC (with Crude Oil) must have the tanks inerted. I know its a fact (been a Master on VLCCs for 13yrs),but I just can't find it in SOLAS or MARPOL etc. Plenty of references saying an IG system must be fitted, but none (that I can find) that the tanks must be inerted.
I'm sure someone will know or find it easily.

Many thanks in advance


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## alastairjs (Feb 8, 2006)

smithax
For the UK, there is a legal statutory instrument which appears to cover the use of inert gas; "The Merchant Shipping (Fire Protection: Large Ships) Regulations 1998 (No. 1012)" Main body 
TANKERS OF CLASS VII(T) OF 500 TONS OR OVER 
Inert gas systems 
There is a link to the relevent part of the UK Statute Law Database here:
http://www.statutelaw.gov.uk/conten...2805377&ActiveTextDocId=2805499&filesize=7795
I believe it is the case that, even when a regulation is approved by the IMO, it is the job of each signature nation to write the agreed regulation into their own legal systems. In the UK this tends to be done via "Statutory Instruments".
Hope that is of some assistance. You will see there are references to other instuments within the body of this one. The topic is also covered in the Maritime & Coast Guard Agency's Regulations here: http://www.mcga.gov.uk/c4mca/ch08r2-3.pdf
Looking on the web it appears that the IMO are still in debate over the minimum size of chemical tanker to be covered by new regs on inert gas installations. There is no agreement yet on the minimum size of vessel to which new regulations will apply, "the discussions will continue at the next session of the FP Sub-Committee, in February 2011, with 5,000 dwt and 8,000 dwt both still on the table". The wheels grind exceeding slow!
Regards,
Alastair


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## Andrew Craig-Bennett (Mar 13, 2007)

Yes, but maybe I am missing something...Smithax seems to be right! The regulations say "...ships...shall be provided with...an inert gas plant..." They don't say "...the vapour space above cargo in tanks and all empty cargo tanks if not gas free must be filled with approved inert gas..." or words to that effect.


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## Billieboy (May 18, 2009)

Right Andrew! it was a Reccomendation for years before becoming an IMO requirement, but some countries have not made it a legal requirement.

It's an old fizzer that has been around for a long time. 

The danger is not when the vessel is loaded, but when it's tank cleaning, all Tanker Operating manuals stress the need for good operating I.G. systems; and the deck water seal of course.


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## smithax (Jul 16, 2009)

Thanks Gents, the closest I've found is IMO Inert Gas 8.2 which it is "essential.....".
It's frustrating, as we all know it a requirement.


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## Satanic Mechanic (Feb 23, 2009)

Maybe another way of putting it !!!!

Has the practice of tank cleaning in an over rich atmosphere been outlawed?


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## smithax (Jul 16, 2009)

Billie Boy,
Have you got the reference for the IMO requirement. 

The reason I asked the intial question was I was told it is Port Requirement only.


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## Billieboy (May 18, 2009)

Let's not get into over rich and lean explosions, I've seen enough.

I remember a big problem with a Russian crewed vessel that could not discharge it's cargo because the deck water seal wasn't full, this acted as a scrubber as well and there were several safety interlocks holding the cargo pumps off and cargo valves closed. It was some twelve hours before I was asked aboard to have a look. took fifteen minutes, there were red lights and flashing lights all over the place! The crew just didn't know what was happening. 

The borsh was good though!


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## Satanic Mechanic (Feb 23, 2009)

Try SOLAS reg 16.3


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## Billieboy (May 18, 2009)

smithax said:


> Billie Boy,
> Have you got the reference for the IMO requirement.
> 
> The reason I asked the initial question was I was told it is Port Requirement only.


Sorry Smithax, have memories but could not point to a book let alone the page that says it. It's been nearly 17 years since I last walked down the gangplank of a tanker. I do Know that it's a Port regulation to have the IG system in class and running prior to cargo operations starting in the Port of Rotterdam. It's in the Master's declaration after berthing prior to operations starting.


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## Satanic Mechanic (Feb 23, 2009)

Billieboy said:


> Let's not get into over rich and lean explosions, I've seen enough.


Thats not what I meant. I mean has the practice of over rich atmospheric conditions *actually been outlawed*. Because if it hasn't then almost by definition, lean atmosphere conditions i.e. IG are not the only option


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## Satanic Mechanic (Feb 23, 2009)

SOLAS REG 16

3.2.1. When the ship is provided with an inert gas system, the cargo tanks shall first be purged in accordance with the provisions of regulation 4.5.6 until the concentration of hydrocarbon vapours in the cargo tanks has been reduced to less than 2% by volume. Thereafter, gas-freeing may take place at the cargo tank deck level.


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## Billieboy (May 18, 2009)

Agree 100% SM, *always less than 1% gas with or without oxygen is the safest gas volume*


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## david freeman (Jan 26, 2006)

I am a little rusty on regs- in Black and white print! Tanks do not have to be inerted-It depends on the Master as to interpretation of his operational proceedures on board as to its actual implementation. No Help There for the barrack room lawyer? But among your operational intructions especially in the 60's after the 'Malpassa -Kinghorkn and Another Shell VLCC? (Matra) blew up or had a tank explosion off the coast of Africa whilst tank cleaning with tradition equipment (Butterworth portable and fixed macines and axia water driven air ventilation fans). I believe the following guide book was a essential part of any ship that was owned or charted by one of the oil majors and was The Instruction book/aid to operations called Tanker Practice BY The International Chamber of Shipping (ICOS) I believe was more catagoric and itemised or gave advise about the use of IG whilst a tanker was in transit loaded ship/lightship or proceeding to drydock and doing at sea tank inspections and possibly Tank Diving(Removing loose scale by hand) whilst simultaneously tank washing and 'gas freeing' in another part of the tank system. You are approaching the subject as a barrack room layer!-good luck to you, But your crew depend on your judgement and that of the mate in how you utalise the plant and ship at your fingertips. Do not waste the experience of history.
THE ICOS Tanker Practice under British Maritime regs may have or is part of the required guides books to be carried in a ships masters library under the Nautical Publications Regs in the 1960's -1990's? and maybe today under the equivalent IMO Guide lines- which a ship may be tied too under its charter party. I am an old F-rt? and an engineer to boot, I may be wrong but I hope not! That's my bit on the soapbox! Your turn now what are you going to do? Good luck!


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## smithax (Jul 16, 2009)

Thanks for inputs.

Billie Boy 16.2 seems to deal with purging rather than a "steady at sea condition"

SM thanks for the input as well. I may to look at the Company Operations Manual, if I can get it, and quote that.

(Thumb)


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## Billieboy (May 18, 2009)

Don't know what company it is Smithax, but the Shell and BP(they invented IG) operating manuals may be treated as bibles where IG and cargo ops are concerned. For other liquid cargoes, I'd take the Stolt Cargo handling manual over any other, especially where, "Blanketing cargo tanks", is concerned. Flue gas from the Boiler or IG generator is not the only inert gas available.


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## Andrew Craig-Bennett (Mar 13, 2007)

I _thought_ Sun Oil invented IG, way back in the Thirties, and BP adopted it to reduce corrosion rates?

Shell had their minds concentrated for them quite wonderfully by the _Mactra_ and the _Marpessa_ tank washing explosions.

Somewhere at the back of my mind is a little footnote to the effect that there was a strong rumour that one of the Chinese coastal tanker fleets was extremely "relaxed" about IG, as recently as maybe eight-nine years ago, and I fancy they argued that they did not "need" to use IG, but it wasn't a fleet that I had to do with and it may be folklore.


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## smithax (Jul 16, 2009)

Thanks Chaps,
I'm not much of a Barrack Room Lawyer, I'm just trying to find out who pays for some inerting.Thanks for the input about it not being a requirement.

The Company concerned is a reputable Manager, but as I'm representing the Charterers it will be difficult to get any Operating instructions.


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## Andrew Craig-Bennett (Mar 13, 2007)

Smithax, I'd be amazed if it isn't a _terminal _requirement.

Mind you, I've been amazed before!

Edited to add - penny drops - should we not be looking in ISGOTT?


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## James_C (Feb 17, 2005)

Andrew,
About a decade ago we were at anchor discharging Motor Spirit into coastal barges midstream off Shanghai. 
Not only did it look like many had just discharged a full cargo of coal (suspiciously large tank 'hatches'), but most seemed to have a family onboard with a few even having a coal brazier burning away merrily down the aft end!
(EEK)


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## smithax (Jul 16, 2009)

SM I see your point now, apologies for my misinterpretation

Andrew as you said, it is a terminal requirement, i'm just tring to prove it is also a requirement at sea when loaded.


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## callpor (Jan 31, 2007)

david freeman said:


> I am a little rusty on regs- in Black and white print! Tanks do not have to be inerted-It depends on the Master as to interpretation of his operational proceedures on board as to its actual implementation. No Help There for the barrack room lawyer? But among your operational intructions especially in the 60's after the 'Malpassa -Kinghorkn and Another Shell VLCC? (Matra) blew up or had a tank explosion off the coast of Africa whilst tank cleaning with tradition equipment (Butterworth portable and fixed macines and axia water driven air ventilation fans). I believe the following guide book was a essential part of any ship that was owned or charted by one of the oil majors and was The Instruction book/aid to operations called Tanker Practice BY The International Chamber of Shipping (ICOS) I believe was more catagoric and itemised or gave advise about the use of IG whilst a tanker was in transit loaded ship/lightship or proceeding to drydock and doing at sea tank inspections and possibly Tank Diving(Removing loose scale by hand) whilst simultaneously tank washing and 'gas freeing' in another part of the tank system. You are approaching the subject as a barrack room layer!-good luck to you, But your crew depend on your judgement and that of the mate in how you utalise the plant and ship at your fingertips. Do not waste the experience of history.
> THE ICOS Tanker Practice under British Maritime regs may have or is part of the required guides books to be carried in a ships masters library under the Nautical Publications Regs in the 1960's -1990's? and maybe today under the equivalent IMO Guide lines- which a ship may be tied too under its charter party. I am an old F-rt? and an engineer to boot, I may be wrong but I hope not! That's my bit on the soapbox! Your turn now what are you going to do? Good luck!


David is probably referring to the Tanker Industry guidelines ISGOTT "International Safety Guide for Oil Tankers and Terminals" first published in 1978 by the International Chamber of Shipping (ICS); Oil Companies International Marine Forum (OCIMF) and the International Association of Ports & Harbours (IAPH); it is now in it's 5th Edition and provides very comprehensive guidelines on the use of inert gas. From my own experience which I have to admit is getting a little rusty, the general rule applied by most if not all the Oil Major Charterers, Tanker Terminals and some Port States such as USCG apply the maxim, if fitted use it at all times, particularly to inert gas systems regardless of the cir***stances. I would guess the cost is included in the rate therefore it's for owners account. Regards, Chris


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## bill connolly (Oct 28, 2006)

At the Sullom Voe Oil Terminal, no tanker with an oxygen level in the cargo tanks above 8 per cent would be allowed to load.
The vessel had to leave the berth and go to sea to bring the oxygen level down.
It was rather expensive for the ship owner.


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## Andrew Craig-Bennett (Mar 13, 2007)

smithax said:


> SM I see your point now, apologies for my misinterpretation
> 
> Andrew as you said, it is a terminal requirement, i'm just tring to prove it is also a requirement at sea when loaded.


Sorry!

Actually, I've just remembered something - I'm sure that there is a warranty in the hull and machinery insurance policy that IGS shall be used. There certainly was such a warranty in the middle 80's when I first got involved with VLCCs and it is very very seldom that the insurers delete a warranty once imposed. So - owner's account.


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## Billieboy (May 18, 2009)

With Crude oil and IG Systems, one does NOT get rusty, the pipelines do!

Operating Seafarers who get, "Rusty", on IG and the regulations(advice), pertaining thereto, usually end up Dead! 

I do hope Smithax, that you are NOT, looking for a way out of running an IG system!


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## smithax (Jul 16, 2009)

Andrew
Many thanks for the H&M point, thats sounds right, and certainly logical.


Billieboy, 
I am probably a bit rusty on the direct operaion of IG, been in an office for over 2yrs, and havn't been C/O for about 15ys

(Thumb)(Thumb)


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## Andrew Craig-Bennett (Mar 13, 2007)

On a similar note, I recollect being hailed across Statue Square in Hong Kong by someone well known to many here either as Cadet Captain in Union-Castle or as Safety Director of World Wide - Bill Codrington (Captain Sir William Codrington, Bt,) with the word's _"Andrew! You're sure to know - what's the regulation that says Koreans have to have hard hats and safety boots - the Old Man thinks I'm running a holiday camp on his ships - I can find the regulation for Filipinos but not for Koreans!" _

The Old Man was YK Pao, of course. I couldn't think of a regulation either. It's in the Filipino POEA Contract. I think we concluded that the requirement for protective clothing was in the HK flag regs and so it "ought" to apply!


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## Chris Isaac (Jul 29, 2006)

Sadly Bill Codrington passed away in 2006.


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## kevinseery (Jul 20, 2007)

The point of inert gas is that the space unoccupied by cargo contains less than the amount of oxgen required for combustion. So if the tank is empty it needs to have been purged with IG until the oxygen level is below 8%. Once the cargo is loaded the space above it probably contains only hydrocarbon vapours and, importantly, no oxgen to support combustion. So really the answer is that IG is only needed when loaded if the pressure in the vapour space falls e.g. at night when the temperature falls, and IG has to be used to keep the pressure positive.(Thumb)


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## smithax (Jul 16, 2009)

For those who are interested, the Owners did pay for the initial inerting, but a few interesting points came to light.

The CP should have stated that the ship was to be inerted on delivery, as the charterers knew of the ships non inerted condition at delivery they could have commented at that time.

There is no broad requirement that a(Thumb) ship be inerted at sea, assuming gas free, as she could be loading/carrying a cargo with a flash point above 60F not requiring IG

Thanks for all your inputs

S(Thumb)


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