Member Info for MCB55

Any major incident that impacts safety/operations and hence lives/cash flow/reputation should always be subject to a root cause investigation to make sure it never happens again! I trust that has been done!?

SG2
I agree in many respects, hence my "underwhelming" comment at Stobie's comment that it was just chance....twice!! Albeit he is a FD and not expected to know much technically, but still he is representing the Company!.
In the professional world of operations/engineering there is no such thing as happenchance! It is or should be all thought through in nauseating detail. The only possibility of chance was maybe the "snag" or latterly if there was a defective rope! I only hope that both instances have been analysed in detail both operationally and technically as to what went wrong and all suitable measures put in place to ensure no further repeat. IF it is/was brushed off as just one of those things that happen...twice....then there really is a total lack of professionalism, and that would be worrying!!

I certainly hope there is no systemic failure in BW operations/engg!
However I am underwhelmed by the Stobie/Stiffel comment that the two failed attempts so far were just "chance"!!

As for the rope being available "at the end of the month", I hope that is conservative as the weather is looking good for the 24th, shame to miss it!

Yup WW on 23rd now gone on windy.com!!

MH,
What weather site are you looking at?
Windy.com looks perfect for 23rd, too far away to be confident though!

Sat 23td weather looks good on windy.com.
Fingers crossed.!

Oops wrong board,,

Saturday 23rd is looking like a good weather window, fingers crossed,

However might still be better than constantly breaking ropes though!

One solution would be to use a constant tension winch, preset to protect the rope, even though it may sound good, BUT what happens if suddenly rope is let out, even a bit, at the critical latch point!?

I agree that a snatch due to heave with a short rope at latch point is most likely cause! As you say the catenary would not absorb much and neither does a short rope! Could be the proverbial 7th wave!

A couple of possible causes of rope failure are:
1) A DP drive off at the critical moment - unlikely IMO!
2) The rope was damaged during early pull in by rubbing/catching at the side of the moon pool, due to AM being off centre - possible I guess? However the point of rope failure was close to the buoy as it happened as about to be latched, any rubbed rope would be on the winch drum by that point.

I also agree!
My question is IF the acceleration due to heave is only ca10%, THEN this is will be well within the swl of the rope or at least well within its mbl (break load), which is ca 2x swl, so what massive overload (ca 2x swl) caused the rope to fail?

WW,
Generally agree, heave is the major, if not the only component, to create added stress on the rope, other than the weight of buoy plus attachments.

BTW I assume the AM has some sort of heave indication!?

aduk,
Fair enough that could be done, i am not a mariner, but can see that, not sure how much heave would be "dampened" though. Also thats what happened with the FPSO in Brazil, they didn't have DP though, so been done before anyway.

Ok accepted!

We (the public) don't know the cause of failure of the rope and probably never will!
It could be:-
1) A defective rope.
2) They reused the previous snagged rope, which was not knowingly damaged.
3) It could be an overlaod, either close to swl or well over. In which case a major problem.

So overall unless the load was at or below the swl (and can be proven to be by load records) and therefore 1) or 2) from above is cause, THEN it is an overload.

The obvious conclusion is that as the lifting system/rope cannot easily be uprated THEN the only way to add a safety factor so it doesn't happen again is to REDUCE the hookup conditions, that is sea state and heave limits!

Aduk,
Agree minimum 2 weeks and may well be closer to a month or more, as always depends on weather. There is no WW on windy.com for at least 10 days. What I really meant was that they will be super cautious next time, no trying in marginal conditions, has to be perfect!

DC,
I agree.
They don't want to wash anymore dirty linen in public now than is absolutely necessary.
As you say they will now go for flat calm conditions (reduced heave and less chance of another rope break!) and the fear of another failure. It MUST be successful next time, otherwise reputation will be damaged!
I believe that the old ragged rope needs removing from the buoy end and a new one fitted, possibly by another vessel such as Olympic Zeus!?
So could be a long wait!