overloading/overbalancing

[babs135]

Following the tragedy of the whale watching boat in Vancouver Island resulting in five deaths, they now think a contributory cause to the accident was the fact that everyone was on the top deck on the port side at the same time.

 

I've often wondered about this on ships that can hold 4000+ people who all rush to one side to see the marine life.

 

How do the crew deal with this? Obviously altering ballast, but how do they do it so quickly.

[sparks1093]

Following the tragedy of the whale watching boat in Vancouver Island resulting in five deaths, they now think a contributory cause to the accident was the fact that everyone was on the top deck on the port side at the same time.

 

I've often wondered about this on ships that can hold 4000+ people who all rush to one side to see the marine life.

 

How do the crew deal with this? Obviously altering ballast, but how do they do it so quickly.

 

It's highly doubtful that all 4,000 passengers aboard will all be topside at the same time, much less rush from one side to another. Even then as I understand it larger ships are less susceptible to this sort of thing.

[CruiserBruce]

I don't think all 4000 could be topside at one time- they wouldn't fit, and certainly couldn't all be on one side, top side, at the same time.

[Cruzaholic41]

Following the tragedy of the whale watching boat in Vancouver Island resulting in five deaths, they now think a contributory cause to the accident was the fact that everyone was on the top deck on the port side at the same time.

 

I've often wondered about this on ships that can hold 4000+ people who all rush to one side to see the marine life.

 

How do the crew deal with this? Obviously altering ballast, but how do they do it so quickly.

 

With those 4000+ people scattered around the ship, all doing their own things, there's no way all of them would rush to one side of the ship at the same time.

[chengkp75]

Following the tragedy of the whale watching boat in Vancouver Island resulting in five deaths, they now think a contributory cause to the accident was the fact that everyone was on the top deck on the port side at the same time.

 

I've often wondered about this on ships that can hold 4000+ people who all rush to one side to see the marine life.

 

How do the crew deal with this? Obviously altering ballast, but how do they do it so quickly.

 

The weight of 27 passengers will affect a 30 ton whale watching boat far more than the weight of even 4000 passengers will affect a 225,000 ton cruise ship. (And before someone points it out, yes, I know that registered tonnage is volume not weight, but it gives a scale of the vessels, and the volume of the ship affects the stability) Since it costs fuel to transport ballast water around, and ballast is only needed when cargo is not being carried by a ship, cruise ships really carry very little ballast for their size. However, their ballast tanks are equipped with "anti-heeling" pumps which can quickly move 200-300 tons per hour from one side to another. If you're thinking, that's a lot of water, but it takes an hour, just remember that 4000 200 lb passengers are only 400 tons. If everyone ran from side to side, the ship would list maybe 1*, and few would notice.

[Nitemare]

I've done more whale watches than I care to and when they announce "flukes on the port side", everyone (and it's more than 27 people) rush to the port side at once.

 

And I've never felt a shifting of the ship's inclination.

 

I'm not buying that excuse.

[BlueRiband]

Following the tragedy of the whale watching boat in Vancouver Island resulting in five deaths, they now think a contributory cause to the accident was the fact that everyone was on the top deck on the port side at the same time.

 

I've often wondered about this on ships that can hold 4000+ people who all rush to one side to see the marine life.

 

How do the crew deal with this? Obviously altering ballast, but how do they do it so quickly.

 

You do have a talent for finding sad stories. Perhaps cruising is not for you seeing that you have ongoing safety concerns.

[Velvetwater]

May I introduce you to stabilizers:

 

 

Also this website:

 

http://passyworldofmathematics.com/mathematics-of-ships-at-sea/

[babs135]

You do have a talent for finding sad stories. Perhaps cruising is not for you seeing that you have ongoing safety concerns.

 

Haha. Yep, I do appear to find sad, tragic and downright awful stories. Don't know how I do it ;)

 

But give up cruising - Never. As my late mum would say 'wash your mouth out at saying that'

 

I'll do my best to find an amusing story just to even up the score :D

[chengkp75]

May I introduce you to stabilizers:

 

 

Also this website:

 

http://passyworldofmathematics.com/mathematics-of-ships-at-sea/

 

Stabilizers are a great invention, but just like airplane wings, they require speed through the medium to work. They also require a certain amount of roll or heel before they react.

[cruiseryyc]

I've done more whale watches than I care to and when they announce "flukes on the port side", everyone (and it's more than 27 people) rush to the port side at once.

 

And I've never felt a shifting of the ship's inclination.

 

I'm not buying that excuse.

 

I tend to agree with you. This boat had been doing this same trip daily for 20 years; I'm sure in that time all passengers at some point were all topside and on the same side. It seems to me this reason is a rush to judgement by the accident investigators; or typical "investigative journalism" throwing ideas out there.

[cb at sea]

The Whale Watching vessel was pretty tiny.....doesn't look like it flipped over...looked like it sank stern first, with the bow poking up.....

[Roz]

Onlookers reported a wave sweeping over the boat, and it was near rocks.

 

Roz

[Flatbush Flyer]

The Whale Watching vessel was pretty tiny.....doesn't look like it flipped over...looked like it sank stern first, with the bow poking up.....

 

 

Though the investigation will figure out the cause(s), an educated guess as to potential mechanical issues would include failure of the shaft(s), and/or their seal(s). Even then, it really appeared to go down too fast for a shaft issue. So, could have been rocks and/or wave.

Wave would've had to be very significant to swamp that boat. BIG wave on one side, coupled with ALL passengers on other side could conceivably have swamped it beyond recovery.

Edited October 28, 2015 by Flatbush Flyer

[NMLady]

I tend to agree with you. This boat had been doing this same trip daily for 20 years; I'm sure in that time all passengers at some point were all topside and on the same side. It seems to me this reason is a rush to judgement by the accident investigators; or typical "investigative journalism" throwing ideas out there.

 

News said a large wave hit starboard the same time all those people were port and it was the wave that caused the extreme shift.

[Sandy Sails]

Don't think it was overloaded either - 27 passengers is about 1/2 of what it can hold.

Edited October 28, 2015 by Sandy Sails

[Aquahound]

Though the investigation will figure out the cause(s), an educated guess as to potential mechanical issues would include failure of the shaft(s), and/or their seal(s). Even then, it really appeared to go down too fast for a shaft issue. So, could have been rocks and/or wave.

Wave would've had to be very significant to swamp that boat. BIG wave on one side, coupled with ALL passengers on other side could conceivably have swamped it beyond recovery.

 

I'm curious as to the true cause as well. I also heard the claims of a large swell but looking at the video that's been released, the water looks pretty calm.

 

This is nothing more than a guess on my part, but the loss of a shaft packing could cause quick flooding and a roll like this.

[davecttr]

4000 passengers at 80 kilos each is 320 tonnes? Hardly heavy!

[chengkp75]

I'm curious as to the true cause as well. I also heard the claims of a large swell but looking at the video that's been released, the water looks pretty calm.

 

This is nothing more than a guess on my part, but the loss of a shaft packing could cause quick flooding and a roll like this.

 

Agreed. I looked up the boat, and it was originally a work boat, converted to whale watching, so who knows what stability calculations were done, either.

[Keith1010]

I too have wondered about not only the safety but that life preservers are not warned.

 

My heart goes out. This was a tragedy.

 

Keith

[Lizzie68]

Following the tragedy of the whale watching boat in Vancouver Island resulting in five deaths, they now think a contributory cause to the accident was the fact that everyone was on the top deck on the port side at the same time.

 

I've often wondered about this on ships that can hold 4000+ people who all rush to one side to see the marine life.

 

How do the crew deal with this? Obviously altering ballast, but how do they do it so quickly.

 

Where did you hear that cause? Our news has been covering every aspect here, and so far the only speculation is a rogue wave. If you are reading the Brit press, they are also reporting freezing conditions. Very inaccurate reports.

[Robinsoncruiseso]

Our news in the US Pacific Northwest is reporting the same as Lizzie68 reported. We will post when we here the results of the investigation. Water can get rough that side of Vancouver Island. Not protected like the San Juan or Gulf Islands.

[babs135]

Where did you hear that cause? Our news has been covering every aspect here, and so far the only speculation is a rogue wave. If you are reading the Brit press, they are also reporting freezing conditions. Very inaccurate reports.

 

One of many suggestions that were put forward. The Media are good at reporting speculation as a truth.

[navybankerteacher]

I've done more whale watches than I care to and when they announce "flukes on the port side", everyone (and it's more than 27 people) rush to the port side at once.

 

And I've never felt a shifting of the ship's inclination.

 

I'm not buying that excuse.

 

It's not an "excuse" - it is, however, a rational and reasonably likely contributing factor. Over two tons of human weight suddenly moving to one side, combined with a wave hitting the other, on a poorly ballasted boat, is a recipe for disaster.

[Roz]

As far as "overbalancing", I'm not sure that's possible or even a word. Wouldn't a vessel be either balanced or unbalanced?

 

Roz