Suez blocked.

[Kukri]

It was possible to embarrass a generation of BP tanker officers by dropping the words “plywood patch” into a conversation.

 

[DJE]

What's that in your back garden?

 

[Fr J Hackett]

Why is he clearing the starboard side?

Still need a bigger digger to be effective.

Doesn't look a particularly large excavator and he needs to be careful working that close to an unstable edge of a water filled body, it's not unknown for one to dig under his tracks and take a bath.

 

[Bajansailor]

It was possible to embarrass a generation of BP tanker officers by dropping the words “plywood patch” into a conversation.

Please do elaborate on this - it sounds quite intriguing!

 

[anoccasionalyachtsman]

Please do elaborate on this - it sounds quite intriguing!

+ 1

 

[BurnitBlue]

Me too. I am still trying to figure out what trimmed by the bow or stern means. In a aircraft it has relavence to the trim tabs on the wings to bias attitude and also for minor adjustments. How does this relate to a 200,000 ton tanker? As a boat owner should I know these things?

 

[Kukri]

Please do elaborate on this - it sounds quite intriguing!

I’ve been trying to remember the name of the BP ship. @Frank Holden will know.

Anyway, they had a problem with one of the sea chests. These days ships carry shaped steel blanking plates which can be fitted over the intakes and secured with studs and nuts so the sea chests can be opened up for survey, thus saving a dry docking. They didn’t have one, but made one from plywood, and fitted it.

Someone hadn’t quite thought through increase of pressure with depth. Unfortunately it lasted just long enough for them to open up the sea chest before it failed and flooded the engine room.

I seem to recall that an RN ship, possibly HMS Endurance, repeated the experiment and got the same result?

 

[Kukri]

Me too. I am still trying to figure out what trimmed by the bow or stern means. In a aircraft it has relavence to the trim tabs on the wings to bias attitude and also for minor adjustments. How does this relate to a 200,000 ton tanker? As a boat owner should I know these things?

Submariners will have a different answer but for surface ships including yachts we trim by the bow or by the stern by changing the distribution of weights so as to alter the fore and aft position of the centre of gravity in relation to the centre of buoyancy.

 

[Kukri]

What's that in your back garden?

Where does that photo come from? It’s brilliant!

 

[BurnitBlue]

Submariners will have a different answer but for surface ships including yachts we trim by the bow or by the stern by changing the distribution of weights so as to alter the fore and aft position of the centre of gravity in relation to the centre of buoyancy.

Thanks. Yes I understood the weight distribution regards to yachts but I wondered if a 200,000 ton tanker would even notice where the cargoe was. I thought you were chatting about movable water ballast while on the move. After all a container ship must load and unload many times to the point that a container ship is never actually empty. Thanks again live an learn.

 

[penfold]

Me too. I am still trying to figure out what trimmed by the bow or stern means. In a aircraft it has relavence to the trim tabs on the wings to bias attitude and also for minor adjustments. How does this relate to a 200,000 ton tanker? As a boat owner should I know these things?

Trimmed by X means the X end is lower in the water than the opposite end, at least that is how I understand the term.

 

[Bajansailor]

Where does that photo come from? It’s brilliant!

It is included in this album of photos in a BBC report - I am sure that it is much in demand by news organisations all over the world!
In pictures: Efforts to dislodge huge ship from Egypt's Suez Canal

 

[BurnitBlue]

Trimmed by X means the X end is lower in the water than the opposite end, at least that is how I understand the term.

Aha. The penny dropped. So this trim is an accident of chance caused by loading an unloading at various ports on the route not a deliberate trim to bias the ships attitude and responce to the helm. So if the ship got into a bow down position she would be (like another poster said) as manouvarable as a supermarket trolley. Thanks.

 

[Frank Holden]

I'm thinking the BP tanker was the one they managed to 'sink' alongside in Kwinana, WA, ... well... sit on the bottom by flooding the engine room.

I see the that a few posts ago Ever Given morphed into a tanker ... did the same thing yesterday on MSNBC.....

 

[Bilgediver]

It was possible to embarrass a generation of BP tanker officers by dropping the words “plywood patch” into a conversation.

I was a later generation. Joined a ship and noted there were patches of Thistlebond on the engine room forard bulkhead. The other side was the Deep Tank . The ship was an ex Empire ship built about 1940.

 

[BurnitBlue]

Yes technically good. A huge telephoto lens to compress the distance. A very small aparture maybe f32 to maintain focus and a long exposure to get enough rays through the lens. A sport photographers set-up.

I recall the critic in the amatuer photography magazine would complain that the building should be lower, the wall higher oh and some clouds in the sky if you please. This was the days before Photoshop and digital. It was always a good laugh to read the unreal world of the painter turned photographer.

 

[Gary Fox]

They laughed at the time, now the training kicks in...

 

[ProDave]

I would love to see the view from the bridge. With containers stacked almost as high as the bridge it bet it would be hard to see much of the canal ahead of you.

 

[dombuckley]

I seem to recall that an RN ship, possibly HMS Endurance, repeated the experiment and got the same result?

***Warning - Thread drift***

The Endurance flood occurred while cleaning out the strainer on one of the main engine salt water inlets. The complicating factors were that the seacock was remotely operated, using an actuator activated by HP air, and the air lines had to be disconnected to remove the strainer.

The valve was closed; and air lines disconnected, to prevent accidental activation. The lid was removed and strainer cleaned out. Strainer was put back in, and air lines reconnected. Unfortunately (1) the lid had not yet been reinstalled and (2) the air lines were reconnected incorrectly. With the hoses connected incorrectly, the actuator opened the seacock rather than keeping it shut, allowing water in through the lidless strainer. The water pressure (of course) was too great to get the lid on, and repeated attempts to close the valve failed (in the heat of the moment it was not realised that pressing the "open" would have shut the valve, until after the HP compressor had failed due to SW ingress).

End result, she came within a gnats whisker of being lost. She was salvaged, but ended up being written off and scrapped.

 

[Kukri]

Aha. The penny dropped. So this trim is an accident of chance caused by loading an unloading at various ports on the route not a deliberate trim to bias the ships attitude and responce to the helm. So if the ship got into a bow down position she would be (like another poster said) as manouvarable as a supermarket trolley. Thanks.

No!! No!! No!!

Loading, stowage, discharging and ballasting are all pre-planned to achieve optimum trim, which is important because it affects both the ship’s handling and her fuel consumption, and it has to be done taking into account the bending, shear and torsional moments on the structure.

It is part of the Chief Officer’s job - actually the main part - and uses a fair amount of IT.

I have now remembered that some Class Societies do sell trim optimisation packages which will in some circumstances recommend a bows down trim. LR certainly do, but I didn’t buy it as I wasn’t willing to spend money to help the charterers unless they chipped in, and they were not persuaded. The Ever Given is ABS, and I don’t know if they do, as I sacked them in favour of LR.