Boat Capsize Evidence

[gonzo]

Alik: Where do you get 80%. One of the things I really dislike is people making up numbers to sound as if they have facts instead of opinions

[Alik]

Originally Posted by gonzo

Alik: Where do you get 80%. One of the things I really dislike is people making up numbers to sound as if they have facts instead of opinions

Statistics of marine accidents... I can't give a link, but this is fact I picked up when I was working in seafarer's training center.

OK, this is fast sample: http://www.mardep.gov.hk/en/publicat.../mai_c2006.pdf
Look on what is operator's factors and what could probably be technical factors, You will get those 80%

[Alik]

Document for topic starter:
http://www.maib.gov.uk/cms_resources...ons%202005.pdf

[Paul Kotzebue]

Originally Posted by PAR

So, Paul, how many 20' pontoon boats you know of that can accommodate 15 people at the starboard rail?

None. But if it can accomodate 15 people at the starboard rail, it will, and the designer should account for that. The alternative is for the designer to determine the maximum safe capacity of the vessel based on USCG or other accepted guidelines.

[sabahcat]

Originally Posted by Paul Kotzebue

In that particular case it absolutely would be poor design. Any boat that is designed to carry people should be designed with adequate stability with passengers crowded to one side.

My 11 ft aluminium dinghy/tender would capsize with 3 people on the gunwale, it probably would with 2.

It must be a poor design.

[Submarine Tom]

Pictures Sachi, do you have any pictures?

[PAR]

But if it can accomodate 15 people at the starboard rail, it will, and the designer should account for that.

This is a gross misunderstanding on your part Paul. No one can be expected to account for every possibility, particularly when boneheadedness comes to play.

Gonzo, 80% sounds about right, without looking up the figures. It might even be a little low.

[Ad Hoc]

PAR

Paul is correct in saying:
"..But if it can accomodate 15 people at the starboard rail, it will, and the designer should account for that..."

You must remember this is a passenger vessel. As such the designer must investigate ALL possible conditions/scenarios that could occur. Whether it should or should not happen is irrelevant.

Passenger crowding on one side, for passenger vessels, the design MUST investigate the possibility of as many passengers pushed/squeezed/forced into one area as humanly possible. Whether this condition is equal or greater than the Flag requirement is again, irrelevant. This MUST be investigated in the initial design stage.

This work is always done during the submission, or preferably before, the submission of the preliminary stability booklet to Flag or Class.

As for:
"..No one can be expected to account for every possibility, particularly when boneheadedness comes to play.."

Correct. BUT, if the designer has not mitigate all design issues, than the culprit, for the accident gets of Scott free by pointing to poor design.

It is negligent of any naval architect, in the commercial field, not to investigate all possible scenarios of passenger loadings. If a passenger CAN get to a location, then it WILL happen.

If the investigation shows that all those passengers crowed to one side, the boat would capsize, then the max limit would be ascertained from the stability investigation. Then, this limit is written into the Operating Manual (again another Class requirement - all these issues are beyond the knowledge of luxury/pleasure market designs). The operating manual will state very very clearly the maximum number of passengers allowed on the vessels side.

The vessel, when delivered will ahve
1) The operating manual, informing the Capt. what is possible
2) The vessel will have a tally to state "No More than XX passengers". (Just as lifts do, for max payload)

Beyond this, there is nothing else the designer can do, save to redesign the whole side to actually prevent ANYONE actually going to the side, or limited to the max, that has been previously calculated.

The latter rarely occurs, since the owner of the vessel wants the layout as such, and wont compromise. Hence any responsibility is then taken by the owner/operator to ensure that the max number of passengers per side, is not exceeded.

This issue is a good case that highlights the very real differences between the luxury/pleasure marker and the commercial one. The new rules and reg's for CE marking and the small boat code etc, that many seem to be whinging about for compliance, is just the tip of the iceberg that commercial vessels must comply with day in day out, which is unknown outside this field.

Hence the requirement for professional naval architects not those....i have software i can draw, ergo i can design!

[Luckless]

Originally Posted by Alik

Most widespread factor of capsize is overload or incorrect loading, that is definitely fault of operator.

Actually, this can't be said to 'definitely' be the fault of the operator. If the operator was following loading guidelines they were provided, and it capsizes, it is the fault of whoever provided the guidelines. (unless of course it is grossly out there, like 100 tonnes on a very small boat.)

[PAR]

John and Paul, we're in agreement that commercial vessels, with passengers for hire, fall under a different set of guide lines. My premises was based on a hypothetical 20' pontoon boat with 15 people aboard (clearly above it's stated pleasure use limit, by any stretch of the imagination), gathered at the rail. This precise situation just occurred last summer with the death of a kid. Guess who was found guilty of negligent homicide.

Yes, in commercial craft we go to much greater lengths, but in the original posters case I suspect they craft didn't comply with any of our accepted standards. Of course this is an assumsion, but reasonably based on the region. Wherein you can see 35 passenger buses, traveling up the side of a mountain, with 65 inside and another 15 clinging to the outside, I have difficulty accepting any responsibility on the part of the designer. In areas where standards and regulatory mandates have been accepted, you don't see this type of behavior.

[Alik]

Originally Posted by Luckless

Actually, this can't be said to 'definitely' be the fault of the operator. If the operator was following loading guidelines they were provided, and it capsizes, it is the fault of whoever provided the guidelines. (unless of course it is grossly out there, like 100 tonnes on a very small boat.)

I was working for 4 years in seafarers training center, developing and customizing stability/loading software for captains and officers. Those days I have studied accident reports on loss of stability, in most cases the reason was overload, mostly shipowners forced captains to overload in order to maximize commercial effect.

The naval architects are always backed by comping the Rules, so there is no argument on subject. It is well known that if passengers crowded on one side heel should not exceed 10 degrees, etc.

Of course, this all works if the boat was designed by professional naval architect and built strictly according to the design. If it is drawn by amateurs, then it is another story (but still ship owners fault - who saved the money on professional design?)

[Paul Kotzebue]

Originally Posted by PAR

John and Paul, we're in agreement that commercial vessels, with passengers for hire, fall under a different set of guide lines.

33 CFR 183 has guidelines for boats and associated equipment. ISO has stability standards for small boats. In any case it is the responsibility of the designer to follow applicable safety guidelines. The guidelines for commercial vessels may be different, but the standard of care required to design the vessel is not. In addition to applicable safety standards, professional engineers (including naval architects) are required to follow the laws of the jurisdiction that issued their license with regard to engineering practice.

Crowding of passengers to one side is a fundamental design consideration regardless of the service of the vessel. If there is room for 15 people on the rail, then 15 people will be on the rail unless the passenger capacity is limited and clearly marked on the vessel. This is equally true for passenger and pleasure vessels.

[Paul Kotzebue]

Originally Posted by sabahcat

My 11 ft aluminium dinghy/tender would capsize with 3 people on the gunwale, it probably would with 2.

It must be a poor design.

Not necessarily. The gunwale is not the same as a seat or a deck with a handrail. If your dinghy capsized with people sitting on the seats it would indeed be a poor design.

[Alik]

Originally Posted by Paul Kotzebue

professional engineers (including naval architects) are required to follow the laws of the jurisdiction that issued their license with regard to engineering practice.

This system of professional licencing is used in US but not in other countrues where a proper degree is already enough to practice naval architecture. As to boat/yacht designers in US, I heard 90% of them do not have any engineering degree at all, but probably they are not allowed to touch commercial vessels? I have seen some small ferries, charter boats, etc. designed by American designers who are not naval architects by education (at least they do not hold Bachellor degree on the subject).

So everything is not easy here, at least we should know who designed that boat in question and what really happened. BUT if design agreement is written properly the designer will not take responsibility for accidents (we used to put this clause in agreement also).

[sabahcat]

Originally Posted by Paul Kotzebue

Not necessarily. The gunwale is not the same as a seat or a deck with a handrail. If your dinghy capsized with people sitting on the seats it would indeed be a poor design.

Your quote

Any boat that is designed to carry people should be designed with adequate stability with passengers crowded to one side.

me and my mates on the gunwale would be passengers crowded to one side.

Or to go another way, would the OP's vessel have capsized with the passengers on seats?