Assalamoalaikum, and welcome back to Orange Shots.
Today's video is going to be rather informal because it's Ramadan,
and I like sitting in front of the window so I thought why not film this way.
So, the question is: How is a ship tested before being delivered?
You've created a gigantic thing
that floats on water and has a large engine
to propel it forward.
But how is the ship tested?
Even a minor welding fault in the giant could lead to water ingress.
Any minor fault in welding could
lead to several stresses on a ship.
There's a calculated amount concerning when a ship can break.
If your calculations are wrong,
chances are some parts of the ship haven't been constructed properly.
So how is it known whether a ship's engine, hull, and whatnot work fine?
Isn't that an important question?
I think this question should be answered in detail,
because the answer is very interesting.
I've mentioned in a previous video that large ships are essentially made in parts.
All the parts are accumulated in a shipyard, and then combined.
To launch the largest ships, they aren't pushed sideways or in the back
because they're too big for that.
They are built in a shipyard, whether a floating dock or a dry dock.
If it's a dry dock, they fill it with water. If it's a floating dock, it's de-floated.
The ship is then floated and removed from the dock via tugs.
Alright, all that's well and good.
Now comes the testing part.
Of course, you're going to test something before handing it over.
You have to guarantee that the work you've put in is faultless.
Yes. This is exactly what they do.
Three different individuals conduct the tests.
The makers, i.e., the shipbuilders at the yard.
The owners, i.e. those appraising the ship.
They always have a representative present when the ship is being tested.
The third is class,
meaning, the registration authority.
They also send someone to verify whether the ship adheres to all regulations.
That there are no violations.
They also verify that
the ship is constructed according to the latest rules and regulations.
All three parties make themselves available once the ship is nearly ready
with only some finishing touches left, such as painting.
But by then, the hull integrity is complete.
The tanks, engine, generators, filters, and whatnot are ready.
Only the final touch-ups remain.
So all three parties are sent onboard
and the ship is sent out to the water before being delivered.
The ship is accompanied by tugs called escort tugs.
The tugs remain with the ship throughout its trial.
Sometimes, also from what I've seen, even helicopters are on standby at some yards
in case something happens when a ship leaves its yard.
This entire process I'm talking about is called sea trials.
You take a real ship and actually test its functions at sea.
This trial ensures that a ship is properly built.
And since ships are so huge,
even if they use the same parts in sister ships,
it's still verified towards the end that they're in good working condition.
They also check the ship's speed with the engine at its full capacity
since every ship is different.
You add 1000s of tonnes, there's bound to be a difference overall in tonnage.
It's not much, just a little, considering the statistics.
So, when sea trials begin.
They first begin with hull integrity
where they make sure there's no unintentional water ingress or leakage.
It's a different story if it's intentional.
But, overall, they check for unintentional water ingress or leakage.
Once the ship is sent out to sea, the ballast is removed.
Of course, it's tested beforehand, too. But the ship is actually on the water, this time.
When the ballast is removed and when all the cargo tanks are loaded,
ultimately, the ship is loaded until it's heavy with all the cargo.
The ship is made as heavy as it's supposed to be when out on the water.
When the ballast tanks are empty
you know for sure when there's any water ingress.
All the ship's fuel tanks are specially monitored to check
the levels, whether there's any irregularity in them.
All this evaluation continues while the ship is being tested at sea.
But there's one more important thing worth checking: the generators.
All the generators are then left on at full load.
If I'm honest, the way we test ships during sea trials,
if we ran our ships at that same load, that could really anger our chief engineer.
This is because they inflict on ships during sea trials.
They push them to their extremes.
The generators run at full load.
The trips are also tried out.
Ultimately, the ship should respond well under pressure.
Its safeties should work properly.
You turn on the boiler and ask the chief officer to turn on all the cargo pumps,
the steam ballast pumps, to turn on the tanks' steam.
Again, the boiler is tested at its full capacity.
Then all of a sudden everything is powered off
to check what happens to the boiler that was pumping out steam moments ago.
I mean, just imagine that, I've seen boilers as large as 16, 17, 18, up to 21kgs.
Imagine what happens once the steam stops.
But all this testing is mandatory for sea trials.
The cargo and the ballast pumps work similarly.
I often tell the chief officer to destroy (the ship's) soul.
When the ship was being delivered, I asked for extra cruelty.
I asked to set the RPM to full without opening the valves,
to send the pump screaming.
That should show how the pump's safety is functioning.
And no, it's not unsafe. You might think it is.
But no, that's how it's tested.
Same's the case with centrifugal pumps, which are steam-driven.
You turn on the steam and set the RPM to full,
whether there's cargo or not, this is how the boiler and pumps are tested.
The seals are also tested, but nothing bad usually happens.
Things are different these days. How we run tests is also different now.
If you're sailing with an old-school chief engineer, they might object
before eventually giving in. But younger recruits aren't that way,
they know times have changed now.
And the most important part, the ship's main engine.
The way we test the main engine during sea trials
is beyond your wildest imaginations.
First the engine is at "stop," then it's suddenly at "full ahead."
Then you by pass the limits, go from "full ahead" to full "astern."
The "crash astern" mechanism is also thoroughly tested.
In case I forgot, this is known as crash astern.
Meaning, the ship is at "full ahead," and immediately switched to "full astern."
This is called crash astern.
This test is conducted right in front of the surveyors.
This all ensures that the main engine works properly.
We also conduct healing tests and other tests to check stability
where we empty one tank and fill another, then empty the third one.
We check the stresses according to our calculations.
And then the actual stresses.
Newer ships have physical SF and BM monitors built in.
We don't just use software for our calculations.
We get physical readings.
When a ship is being delivered, we always say
that the crash astern test is conducted only once in a ship's lifetime
never to be used again. Which is very true.
And the moments aren't as rigorous as they are during sea trials.
From dead slow ahead to half ahead to full ahead
and then all that in reverse.
The last engine test we conducted was so rigorous it shook the whole engine's block.
It was then tested with large spanners attached.
One time a ship's boiler's steam valve started leaking.
A 600 mm diameter valve
It had a large controller, and it started leaking.
If you've seen boilers on ships before
you can imagine how big the valves are.
Imagine installing, removing and fitting them.
But once you test everything
and then the ship is delivered and yours to sail.
If you encounter problems later, that could prove inconvenient.
It will be a lot of inconvenience.
So it's best to go all in during the testing phase before it's delivered.
This way you won't face problems later.
So I thought I had already made a video about delivering ships,
about how ships are launched during delivery,
why not share how they're tested while being delivered?
How is it ensured whether the ship being launched is in good working condition?
I hope you enjoyed this video.
If you also learned something new, do like, share, and subscribe to the channel.
In the meantime, if you want to find out how ships are launched,
click here.
If you want to know why shipping is on the decline in Pakistan,
click here.
Until my next video, take good care of yourselves.
Do remember me in your prayers.
With tons of love to my Orange Shots family,
and to-be Orange Shots family.
This is me, Zahid Nisar
You're watching Orange Shots.
Until my next video,
ALLAH Hafiz!