Assalamoalikum and Welcome Back to Orange Shots
We have already talked about how a Ship moves !!
Ship's stern is curved from both sides,
and it's curved longitudinally as well
it's a kind of a conical bowl behind ship
Why is it like that?
The reason behing all of this is, there is a PROPELLER behind every ship .
that's driven by ship's main engine
with every revolution of Main engine, the propeller rotates
The propeller however is Just like a FAN
The air you feel coming from a fan is ...
actually the air the this FAN is sucking from behind
Ship's propeller replicates the same principal
It sucks water from ship's forward and throws it to the aft
To suck this water, the propeller needs space
That's when this shape of "stern of a ship" comes into play
It helps propeller suchk water from both sides of the ship equally
this shape helps maintain a steady flow of this water.
& when the propeller performs this action of
"sucking & throwing" water,
This in turn pushes the Ship ahead.
By adopting this shape we give our propeller a chance to take good suction ..
and hence good efficiency.
Now that we know how a ship moves, let's talk about how she turns..
I mean considering the huge sizes of vessels
carrying hundreds of thousands of tonnes of Cargo ..
wouldn't be easy to turn such giants ... Right??
Then how a ship actually turns
We use Rudder to turn the ship around
Rudder is a kind of vertical plate that is fitted next to propeller
The water sucked by propeller is thrown on the Rudder with a force
& turning this Rudder will change the direction of the ship
Rudder is not exactly a vertical plate
But just for understanding the matter let us consider that Rudder
is a vertical plate that is fitted beside the Propeller
Towards the aft of a ship
When the rudder is a neutral position
The water thrown by propeller flows to the sides of the Rudder
And the ship does not turn
When a direction is given to this Rudder
The water thrown by a propeller will be deflecting from the surface of the Rudder
In an ideal situation, every action has equal and opposite reaction
No this Rudder is directly connected to the ship
This deflection of water from the surface of the Rudder
Causes whole vessel to turn in a certain direction
This rudder is actually turned by our steering gear
Still in care is directly underneath the deck where I'm standing right now
And this is the actual steering gear room where all the equipment is fitted
These motors turn the Rudder to the port and starboard
Ships steering gear is actually quite big
But ships steering wheel is not so huge anymore that it used to be ...
Steering wheels have reduced in size but not the steering gear
That is because the Rudders are huge and propellers are throwing a lot of water on those Rudders
As the ships have overall grown in size
That means the ships have huge engines now
And then huge engines rotate huge propellers, the amount of water displeased will be a lot
To rotate that Rudder amidst such humongous flow of water, you need huge steering gear
You won't be able to steer your ship if your
steering gear is not big enough
These motors fitted to my left and right
Will move the Rudder to Port and Starboard
That in turn move the vessel to port and starboard
There's a lot of difference between steering of your Car and Ship
While the steering wheels are of the similar size
The steering gear in your car is much much smaller in comparison to steering wheel
But it's much larger on ships comparing to it's steering wheel
Process of turning a ship is quite simple
The bridge move the steering wheel to Port and Starboard
The signal troubles in this box via Tele Motors
This box translates the signal and relays it to the steering motors
They are 2 in number here
One of them always act as a back up
These steering motors then move the RAM
The Rotating action of this RAM then rotates the Rudder
and that is how the Rudder turns to Port and starboard
There is one more difference in how your car & the ship turns
In cars, turning the wheel left or right turns a car's wheels
and your car bodily turns to the left or right
In case of ships, the principle isn't the same
As the Rudder and Propeller, both are fitted in the aft of a ship
So when you move the rudder of a Ship
the Aft part of a ship moves to the left or right First
And that in turn Changes a Ship's Heading
So there's a difference of ergonomics when we compare the
turning action of a ship or car
Also consider that my ship is around 274 meters long
when turning a ship you have to remain careful
The ship won't bodily turn to port or starboard
You have to remain very very careful about the movement of your ship's stern
The ship's steering is usually operated from the bridge
in case of a problem, where bridge is unable to operate steering
We can always come here, and operate the steering from here
In steering gear room, we have all the essential tools and equipments
required to steer a ship
In case of any steering failure
One person has be stationed here to operate the machinery
Talking of Equipments, we have the old fashioned "Sound Powered Phone" here
The one where you need to rotate the Electromagnet to ring the bell.
It comes in very handy in case of an Emergency.
Then we have our regular phone as well
We use this phone to get heading instructions from Bridge
because the person navigating the ship is on the Bridge
So he has to give orders from Top
That order is then executed here
We have the Rudder Angle Indicater here too ..
This shows us the actual angle of the Rudder
because obviously we cannot see the Rudder, it's Submerged in the Water
We also have the Gyro compass repeater here
It repeats the heading from Gyro Compass (Fitted on bridge)
If the bridge orders us to steer "260 T"
By looking at this Gyro repeater I can make out
if i am steering 260 T indeed.
I have really powerful Speakers here too
In worst case, when I am unable to hear sound in my headset
I can recieve orders and alarms through these Speakers
This the RAM i was talking about earlier
and these indicators tell us how much helm is given
Green markings indicate order to the Starboard side
and Red markings indicate order to the port side
From this RAM we will get indication about how motors
have rotated the Rudder stock to the port or starboard side
and the Rudder andle indicator will display
the Physical movement (Rotation) of the Rudder
Rakesh, Can you Move Rudder to 5 Degrees to port please..
Okay, Thankyou Can you come back to midship
Perfect ... Can you move it 5 degrees to starboard please
So, that's how we execute the orders from Bridge
That's how we recieve orders and then steer the Ship from local controls.
Rakesh, Thankyou very much for being with me on the phone.
So, that's Exactly how a ship turns.
and that's why when a ship's engine is stopped,
when the propeller is not throwing water on rudder,
The ship won't turn whatever the angle of Rudder is..
Rudder will only change it's angle once any helm order is given
But your ship won't turn,
As propeller isn't rotating because Engine isn't running
You can watch how the emergency generator of a ship runs by taping "here"
and if you want to know if the Earth is Round or not,
I will link that video "here"
until the next video, take care of yourself
Keep me in your prayers
With tonnes of love for my "Orange Shots" family
and"to be" Orange Shots Family
This is me Zahid Nisar You are watching Orange Shots
Until the next video, Allah Hafiz