Assalamoalaikum, and welcome back to Orange Shots.
At the beginning of last year,
the Ever Given ship incident happened.
The Ever Given ship got stuck in the Suez Canal
and despite numerous attempts to free it,
Tug boats happened to play a key role.
The tug boats managed to free a mammoth ship.
These tug boats pulled the ship out towards the Great Bitter.
That's where the ship finally dropped her anchor,
and other issues were taken care of.
But the question here is: How did such small boats
that looked like ants compared to a mammoth,
how do they manage to get ahold of such a gargantuan ship?
Where do such small tug boats get all that power?
To be able to pull a giant ship?
In today's video, besides telling you all about tug boats,
I'd like to address a misconception too.
However, I think we're moving too fast for now.
Before I clear that misconception, there are many things you should know.
The first thing: What is the purpose of tug boats?
If a narrow passage is long
like the Suez Canal or the Panama Canal;
tug boats assist large ships in such areas.
This is called escorting a ship.
If, in case, a ship gets into a bit of trouble,
possibly causing a blockage,
the tug boats pull the ship aside
to keep the passage open for other ships.
The ship's issues are then dealt with later on.
Another duty tug boats fulfil is manoeuvring ships.
In terms of size, ships are gigantic.
Sharp turns, especially turns near a port
aren't something a ship can do easily on its own.
Besides size, when a ship is in shallow waters,
its propellor doesn't get enough water to work properly.
The rudder can't work efficiently either.
That restricts the manoeuvrability of the ship.
The third thing tug boats help with is helping berth and unberth a ship.
In simple terms, parking and unparking a ship.
The manoeuvrability of the ship is restricted as it is.
And if the ship tries to give its engine a tiny kickstart, turning its propellor,
chances are
if the ship loses control, it might cause a lot of damage.
And we're back to the same question again: How do small tug boats handle big ships?
The answer to this is hidden within two factors.
The first is engine power,
the second, hull design.
Tug boats have highly powerful and efficient engines
and they can generate a great amount of power.
Typically, diesel engines are employed in such tug boats,
and if you're interested in automotive technology,
you must know that if diesel engines and petrol engines
are the same size, let's say 1.8 litres.
The diesel engine's initial tug may not be enough,
but it can produce more power.
And that's exactly why these are used in tug boats.
New tug boats come with powered engines,
so they can definitely produce a lot of power.
Also if you want to figure out
how powerful they are;
the size of a tug boat is very small.
Around 8-10 meters, or 10-12 meters,
or if you make it even bigger, around 20-25 meters.
But a tug boat's size-to-power ratio
is approx. 9.5.
Which is a lot. Quite a lot.
If I were to explain it to you simply,
you could pull a train with this type of engine.
It's an engine powerful enough to run a train
and it's found in tug boats. I'm explaining this as simply as I can.
If you go into the nitty-gritty of it, of course,
there are other small factors too.
Now after getting all the power, the tug boat's hull should also be strong enough
to bear this type of power.
If you were to fit such a large engine into an object
with a hull, outer shell, or body that isn't strong enough
to handle such an engine,
that object is bound to break.
So the hull definitely has to be strong.
Now, the second important thing is:
Besides the engine's own power
the tug boat has its own power for pulling, called a bollard pull.
In simple terms, a bollard pull is
the tonne force with which a tug boat can pull a ship.
The more the engine power is,
the stronger the bollard pull of a tug boat is going to be.
You also need a powerful winch to execute a bollard pull, one that doesn't; break.
Normally the bollard pull I've seen is around 8-10 tonnes.
On newer tug boats, it's 120-130.
In fact, the latest tug boats on the market
feature around 300 tonnes.
In such tug boats, the winch is at the back of the boat
for pulling a ship.
The rope also has to be super strong,
strong enough to withstand a bollard pull.
For this, they employ wire ropes made out of steel.
In fact, there are new ropes on the market
stronger than steel, rust-resistant, and durable.
They use strong ropes
so they don't break when the tug boat executes a bollard pull.
To support such power, tug boats come with 2-3 engines.
The engines can also be turned around quickly.
Since a tug boat needs to push and pull a ship,
its propellor can turn a whole 180 degrees and exert a forward force.
A power shift capability on a tug boat is usually great.
Then there's one more thing.
You use tug boats to help with a ship's manoeuvrability.
For that, a tug boats manoeuvrability is flexible enough for it to turn side to side,
back and forth easily,
To make such manoeuvrability practicable,
apart from the propellor, which I just talked about,
the next important thing is the hull design.
Ships usually feature bilge keels,
present at the turns.
Tug boats have them in their forward area, and at the bottom (pointed).
And they help with manoeuvrability.
A tug's hull design is built in such a way that the more power the tug exerts,
the hull gradually sinks underwater.
Tug boats don't have big enough drafts,
but relative to their bodies, the draft is 1-1.5 meters
which is quite a lot.
Compared to how big tug boats are.
1-1.5 meters is big enough.
Also, when they exert power,
the hull sinks deeper, giving rise to resistance and friction.
This all helps tug boats
pull at ships with a great amount of force.
Ships usually have tug points marked.
Those are the points tug boats and push and pull at.
But despite all of that fanciness, there's one catch.
You must think that
ships can be pulled regardless of the speed they're going at.
No, that isn't right.
No matter how big or powerful a tug boat gets,
it can't be as big or as powerful as a ship.
It's the same example with elephants compared to ants,
no matter how big an ant gets, an elephant is, after all, an elephant.
An elephant could crush an ant in an instant.
It's the same scenario with tug boats.
Until a ship is properly slowed down,
tying a tug boat to a ship could
be dangerous for a tug boat and its rope.
That's because a ship's momentum is pretty great.
I've said this plenty of times before.
If you tie a tug boat to a speeding ship,
the rope could instantly break on impact.
That's because the force the ship is probably exerting
would be quite a lot.
A tug boat would never be able to handle that.
Now imagine a ship's anchor falling on a tug boat. There'd be nothing left.
So you can well imagine
that a tug boat may be able to handle a ship
but there's only so much a tug boat can handle.
If you tie a tug boat to a ship's back, it will be able to assist the ship,
help slow it down by putting its engine in reverse.
But a tug boat cannot just stop a ship at any time.
Think of it like taming an elephant. Wherever the ant pulls, the elephant will follow.
No matter how powerful a tug boat gets, it can't turn a ship whenever.
So if you liked today's video,
and want to learn about ship engines,
tap here.
If you want to know whether seas have mountains,
and how the mountains are measured,
I have a video about that linked here.
Until my next video, take good care of yourselves,
always 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.
And until my next video, ALLAH Hafiz.