Slight navigational error....

[Athy]

Not exactly. Unstable would mean not stable, it would prefer to take up another more stable position like rolling over

 

Tender means 'moves about a lot'. You'll know if you step onto a canal boat that is tender as it rolls under your feet. Tawny isn't particularly tender, so it always catches me out when I get onto a more skittish boat

 

Richard

Prone to wallowing, then. Trojan doesn't do this too much but I have stepped on (and been surprised by) boats which did - most notably a small Springer which displayed more lateral movement than a mark one Deux Chevaux. I didn't quite disappear over the other side.

. I am not sure it means it is actually unstable, more like less stable.

What a salesman!

 

Thanks for enlightening me, gents.

Edited January 6, 2015 by Athy

[howardang]

Tender? From the context I guess that this means "unstable". Is this correct?

No, not quite. Tender means that the tendency to return to the upright when a vessel is deflected from the upright by an external force is small, and a tender vessel will roll more and take longer to return to the upright. It doesn't mean that it is unstable. It has a small righting lever. On the other hand a stiff vessel has a large righting lever and will return quickly to an upright position. If very stiff this can be very uncomfortable but the vessel is very stable.

 

Howard

[Tony Brooks]

Prone to wallowing, then. Trojan doesn't do this too much but I have stepped on (and been surprised by) boats which did - most notably a small Springer which displayed more lateral movement than a mark one Deux Chevaux. I didn't quite disappear over the other side.

 

 

I thought wallowing was movement in the other direction like when you cross a wave. Some boats are more prone to it that others and I understand narrowboats tend to wallow less for their length because have little flair on the bow and tend to go straight through waves. Probably wrong though.

[RLWP]

A wallowing boat is moving with difficulty through a rough sea. I'd expect it to be reacting slowly to waves and shipping water

 

As Howard says, tender relates to how a boat rolls

 

Richard

[Dharl]

 

It usually means a boat tends to roll from side to side more. I am not sure it means it is actually unstable, more like less stable. However if cargo shifted during roll then it would tend to have a larger effect.

 

I note that there is talk of a wave and that it had made a fairly tight (for the open sea) turn so a wave, the turning force and being tender may have allowed something to shift. The bit I am not sure about is which way it would lean during a turn. I have known inland boats that lean out and others lean in. I suspect the ones that lean in tend to do it at higher speed when they slide up a wall of water they have pushed to the outside.

 

Waves in the Solent are fairly negligible, well for the size of vessel we are discussing here anyway, different story if we took one of our inland boats on it! I think the mention of the wave came in discussing he Cougar Ice incident of Alaska (2006) when during a ballast transfer situation a large wave hit the vessel and was one of the reasons she put on a large list.

 

With regards to direction of roll on a turn, people might be surprised that its to the opposite way of the turn. The Hoegh Osaka was turning hard a port and so was listing to Starboard as she went round.

[nebulae]

When seen from the shore opposite Calshot Castle,the old transatlantic liners took on quite a list when rounding Calshot Spit. More noticable with these huge ships,but same principle with modern vessels,particularly with a flat bottom and a lot of top hamper.

[tony collins]

I remember when one of the US space capsules parachuted back into the ocean, it actually settled upside down. It was described by one of the astronauts as being a in a "stable two" position.

 

Edit:

 

 

With regards to direction of roll on a turn, people might be surprised that its to the opposite way of the turn. The Hoegh Osaka was turning hard a port and so was listing to Starboard as she went round.

 

Not so surprising really just watch a truck being driven slightly too fast around a curve, it adopts a similar attitiude.

Edited January 6, 2015 by tony collins

[RLWP]

I remember when one of the US space capsules parachuted back into the ocean, it actually settled upside down. It was described by one of the astronauts as being a in a "stable two" position.

 

Edit:

 

 

 

Not so surprising really just watch a truck being driven slightly too fast around a curve, it adopts a similar attitiude.

 

Or any 1970's French car

 

Richard

[MtB]

 

Or any 1970's French car

 

Richard

 

Wasn't the Citroen DS noted for specifically not rolling when cornering, thanks to it's hydraulic suspenders?

 

http://www.citroenet.org.uk/miscellaneous/hydraulics/hydraulics-1.html

 

 

 

 

MtB

 

 

 

(Edit - wrong link!)

Edited January 6, 2015 by Mike the Boilerman

[howardang]

I see the latest reports are saying that they might try to refloat the ship on Wednesday, although they also say that she has been holed by shifting cargo allowing water ingress. That makes a refloat more difficult and this is reflected in the comment that they have "difficult calculations" to make. Lets hope they can do it before the weather breaks.

 

Howard

[MtB]

The thing about the 'water ballast computer problem' theory that bothers me is that if true, why not just pump OUT all the water ballast? Then da ship will float off at the next high tide.

 

I doubt I'm the only person to think of this so there MUST be more to it than that....

 

 

 

MtB

[RLWP]

What if it is a fuel ballast computer problem? Maybe they trim the ship by shifting fuel about.

 

In fact they do sort of do that anyway to deal with full and empty fuel tanks

 

Richard

[billS]

balloons - lots and lots of helium balloons,

[MtB]

What if it is a fuel ballast computer problem? Maybe they trim the ship by shifting fuel about.

 

In fact they do sort of do that anyway to deal with full and empty fuel tanks

 

Richard

 

 

Early BBC news reports stated it has 80 tonnes of fuel on board. Is this enough to cause such a list?

 

MtB

(I doubt it, given the ship displacement was also reported as 50,000 tonnes.)

[RLWP]

 

 

Early BBC news reports stated it has 80 tonnes of fuel on board. Is this enough to cause such a list?

 

MtB

 

80 tonnes! Is that enough to get around the Isle of Wight?

 

Richard

[MtB]

Quite a bit of energy in 80 tonnes of bunker fuel oil, I bet....

[RLWP]

Quite a bit of energy in 80 tonnes of bunker fuel oil, I bet....

 

More in 80 tonnes of sugar

 

Richard

[howardang]

Early BBC news reports stated it has 80 tonnes of fuel on board. Is this enough to cause such a list?

 

MtB(I doubt it, given the ship displacement was also reported as 50,000 tonnes.)[/quot

 

The reports I have read say that she had around 500 tonnes of bunkers on board which is not a lot for a ship of that size but she probably intended to top up in her next port.

 

Howard

[furnessvale]

balloons - lots and lots of helium balloons,

One of the suggestions is to dig a trench alongside and "slip" the ship into it.

 

That's OK but it will make a mess of the cricket pitch.

 

George ex nb Alton retired

[churchward]

Early BBC news reports stated it has 80 tonnes of fuel on board. Is this enough to cause such a list?

 

MtB(I doubt it, given the ship displacement was also reported as 50,000 tonnes.)[/quot

 

The reports I have read say that she had around 500 tonnes of bunkers on board which is not a lot for a ship of that size but she probably intended to top up in her next port.

 

Howard

It must be quite hard to pump out too in a ship that does not have any power. The oil is almost a solid when cold needs to be heated before it can be used in the engines.

[bizzard]

If they're trying to reduce its draught in order to refloat it, by removing ballast and fuel, which would be low down will make it very dangerously unstable. I think they'd need to unload at least all of the high up weight of its cargo, if not all of its cargo.

[howardang]

It must be quite hard to pump out too in a ship that does not have any power. The oil is almost a solid when cold needs to be heated before it can be used in the engines.

The bunkers on board are MDO, not heavy oil, so they won't need heating.

 

As far as pumping out both fuel and water, they would use portable salvage pumps rather than the ships own pumps. However, it is a delicate operation because of stability issues so they need to plan it carefully before starting.

 

 

The latest BBC News at 2200 says that the refloating attempt has now been delayed because she has taken in more water than first thought. Apparently some cargo has moved, and it seems that she has been holed. I fear that this could turn into a major operation, especially if the bank under her scours and causes her to shift.

 

 

Howard

Edited January 6, 2015 by howardang

[Timleech]

http://www.handyshippingguide.com/shipping-news/two-different-types-of-freight-vessels-involved-in-contrasting-cargo-ship-incidents_6064

[howardang]

Latest news is that at HW today the Hoegh Osaka refloated herself and is now being towed to a holding position in Southampton Water. She still has the severe list so there is still a lot of delicate work to do but It's good news and sighs of relief all round!

 

Howard

[churchward]

Latest news is that at HW today the Hoegh Osaka refloated herself and is now being towed to a holding position in Southampton Water. She still has the severe list so there is still a lot of delicate work to do but It's good news and sighs of relief all round!

 

Howard

A short video here.

 

http://www.telegraph.co.uk/news/uknews/11330647/Stricken-cargo-ship-Hoegh-Osaka-is-drifting.html

 

They are saying it has a 52 deg list when floating.