Yes, using the Let go method. You can read what precautions needs to be taken when using anchor for stopping ship in emergency - www.marineinsight.com/guidelines/9-points-remember-dropping-ship-anchor-emergency/
@@kurmarao9297 dropping of anchor is only applicable on harbor or shore vicinity, but if your vessel is underway on high seas,those reversed method will be better.
If there is space the fastest way to stop a vessel is to make a hard turn. Keep full speed, give full rudder (best effect is if you turn so the propeller effect is helping the turn) until 90 degrees from the initial course. Then reverse engine until stopped. This manoeuvre can not be done in restricted waters, like in a canal or river. In more restricted waters it possible to make repeatedly zig-zag manoeuvres to help reduce the speed. This way you will have a bigger surface area against the direction of movement.
Short version; use reverse as your brakes, making sure rudder is in straight position, unless you want to change bow direction. Then adjust rudder accordingly. Practice makes perfect!
Thank you sir....I'm a cadet so it's very informative for me and please keep upload videos like this so I can gain my knowledge before joining a ship😊🙌
We are glad that this video is helpful. We regularly share videos on maritime knowledge. Please do Subscribe to our channel and share the video to spread the knowledge 👍🏻
Not *entirely* true that a sudden stop isn't possible, but that is referred to as running aground. After all, the only thing harder to stop a water craft is stopping a spacecraft. I'm also old enough to remember how synchro motors that the old engine telegraphs required. A ship can stop on a dime, it's just that that dime has to be pretty damned big, as in miles. Unless it has a handy continent to run into, then it'll stop swiftly, but few will appreciate that kind of a short stop. Excellent video!
Won’t reversing the direction of the propeller while moving forward create a vacuum and make the rudder usable and cause a loss of control? This seems dangerous, and I doubt captains would ever stop like this.
What you tell drop heavy gravity hooks in sea to stop ship I have heard this trick in my early childhood When people tells about how to stop a ship immediately other method that is preparation to stop ship are new for me and very knowledgeable Thanks for this video👍
for the crash maneuvering topic, you have said fuel cam will not change its position due to running direction interlock as per my understanding running direction interlock only stops fuel injection by sending signal to cut out servomotor, it is no where responsible for stopping cam rotation . should'nt it be when we give astern command on telegraph , air distributer cam and fuel cam reverses direction ,but when we give air break fuel will not be injected due to running direction interlock. my doubt is fuel cam should also turn, please clarify
Thank you for the comment. Ship operations are indeed always interesting for those who are not aware about it. Check this video too-- ruclips.net/video/DSMswMR4UfM/видео.html
I used to live on a 72ft boat, we've never used this crankshaft-reversing method. Newer engines are never directly connected to the prop, a transmission is installed in between which makes it easy and quick to change from forward to neutral to reverse...
not only because it makes it possible for a fixed prop vessel to have its engines running without the prop spinning, but also because most engines and camshafts aren't designed to run in both directions.
When the ship is moving at full speed and to stop it, fuel is curoff....due to the speed of the vessel and the momentum, the engine will keep rotating in the ahead direction till it comes to rest. For immediate stoppage, crash maneuvering is done by applying brake air.
I don't think you need to explain the automobile break because the specific gravity on the land is different than the water and besides ground braking relies on friction (correct me if I'm wrong).
I have a question for you What is the procedure of changing direction of a space craft which is in the space and how the thrust work in empty space. According to the Newtons third law of motin.
As soon as the fuel kicks in, the crankshaft hence the propeller will start rotating in the astern direction, however, due to the momentum of the ship which is still sailing ahead, it will take little time to get it in the aster direction.
There's no truth to that saying,,, you can't teach and an old dog new tricks. I never knew the props turned individually. Not sure how I got here but worth the time to stay. 😃
Bit confusing it is. How the changing firing order will reverse the direction of rotation of engine crankshaft? Suppose it is 4-1-3-2, what will be the order to reverse the direction of rotation? And how it is possible? As pistons are getting fired as usual. It is 2 stroke engine having suction compression and expansion exhaust at a time. For changing crankshaft rotation you have to change the direction of force application on crankshaft.
As you said correo, for change of direction , the direction of force applied on the crankshaft needs to be changed. The crank webs are scattered at different angles for each unit. Hence, for revesing the direction, those units firing order are choose Whose crank web assist in reversing the engine.
So, HOW TO BRAKE? The CAPTAIN DOES NOT REACT. The doctor is with him. I am in charge, I see a lot of controls but I do not know where to start. The rocks are near and I need to break. The people is shouting outside. The port control is talking to me and they say "diminish 25 and head 270 NE". I ANSWERED them: "Good afternoon to you too, don´t forget good manners" Sorry I went out of topic, I talk a lot, that is why the captain lost control...SO, How to Brake?
The video is well researched. However, your statement is only correct for a controllable pitch propeller which is not the topic we explained in the video. Hope this clarifies.
Please do check this article for further information - www.marineinsight.com/naval-architecture/controllable-pitch-propeller-cpp-vs-fixed-pitch-propeller-fpp/
With my sailing yacht, in a man over board situation, I shift the gear into idle, and steer a circle. But that will not work so easily with a 500-ft keel :-).
marine insight: most of the boat the bottam using wood but big ship using for steel or wood.if otherwise big ship bottom make steel how to floating in the sea.please can you clear my dought.
Power of displacement when any obeject enters in water it displaces water equal to its own mass thus water exterts upwad force on it so if the obeject is denser than water it sinks but jf its less dense it floats . Steel ship floats because of this air inside the ship makes air ship combo less dense than water hence it floats for eg when titanic hit iceberg water statred entring it displacing the air when enough water displaced air and took its place ship water combo became more dense than sea water and it sank
1.K bye reversing the direction of rotation of propellor is there any stress created on petals of propellors due to moving of ship "i mean while breaking" 2.What will will happen if the ships disel main engine is replaced with electric propulsion system i mean by connecting numbers of motors radially with shaft of propellor this can either save fuel 😅😅😅😅 2 question is it possible
1. The direction is reversed when the engine is completely stopped. If, during emergency, the direction is reversed while engine is in ahead direction, it will incur stress on the engine and shaft. 2. There are ships which are propelled using motors, however to run the motor, the electricity is generated onboard ship by burning fuel. :)
@@marineinsight yaa but using electric propulsion the direction of rotation can be reversed quikly 3. I heard somewhere that boilers is used in ship. what is boiler.? is it used to separate salt from sea water or there is any thing like steam powered propulsion i mean steam engines..?
Hi Abdul Boiler is used to generate steam which is used in various auxiliary systems such as heating up of fuel, sludge, engine jacket etc. Please check this video - ruclips.net/video/QHS2qHY8xUw/видео.html For Converting saltwater into Freshwater, we use Freshwater generator- ruclips.net/video/txziUwXd0cM/видео.html
A ship must have large iron plates on the area which is inside the water...these should be constructed in such a way that the remain closed at the time of sailing and at the time of emergency these plates should be open towards outside...
But these plates must be fitted on side of the ship which remain closed with the body of the ship ...so that their is no impact of wind on it..space should be given on the side of ship so that when these plates were closed, they fit in that space
@@dr-khursheedahmed712 Noted, However, imaging a situation when the ship is in rough sea or wind is changing its direction due to rough weather. Now to stop the ship or during emergency stops, we opened these plates. But instead of increasing the resistance for stopping, it can also assist if the wave or winds is striking the plate from the back !!
Compare the ship engine vs a car engine. Now imaging the size of the gear box and amount of force required to turn the gear and loss of power... The easiest way is to reverse the engine or change the pitch of the propeller.
MV is for Motor Vessel (used for dry ships such as container, bulk carrier etc.) MT is for Motor Tanker (used for tanker ships such as oil, gas carrier etc.)
In emergency situations. When ship is moving forward direction with speed 20 knots. If we drop anchor in to the sea that is enough to reduce the speed or stop the ship
first we need to reduce the ship speed to get faster result (stop). If the anchor rest in the seabed (in areas with less depth), the it will resist the ship movement and help stopping it.
@@travelinfoandtech9490 During roough weather when the ships and waves are coming from different directions, it will be hard to use them. Inturn, Sails are now used in cargo ship to assist in propulsion.
very informative and great video.please upload more educational videos like these.😁😁😁😁
Thank you for liking it. We are continuously working on producing helpful content. You will see more such videos every week. 👍🏻
@Nathanael Harlemopo
Nobody talk about us😥.
People always forget the importance of the tug boats.
Hi Kevin
We will definitely make a video on the importance of tugboat. 👍🏻
Your job is a great job
Dont worry some of us k ow how important you guys are. I do feel your pain. My job which isnt as cool as yours, we too, tend to get forgotten about
Tug boats r used recently in suyez canal. Pl explain about tug boats 👍
In short u will reverse direction of propeller 🤭
Yes, and in case the propulsion power is not available or ship needs to be stopped urgently- those methods are also explained in the video :)
@@marineinsight is it let go method by dropping of an anchor
Am I correct....?
Or any methods...?
Tell me sir..???
Yes, using the Let go method. You can read what precautions needs to be taken when using anchor for stopping ship in emergency - www.marineinsight.com/guidelines/9-points-remember-dropping-ship-anchor-emergency/
@@kurmarao9297 dropping of anchor is only applicable on harbor or shore vicinity, but if your vessel is underway on high seas,those reversed method will be better.
The knowledge of Indian men knows no bounds
🙏🏼
Good job guys,your video is well explicit.
Medium left, Sharp Right, and bank , Good Job Samir, you stoped the ship
Aye Aye 👍🏻
Explanation is very deep & point by point. Great work!
Thank you for the comment. Please do share and support 👍
very excellant demo to stop the moving ship.
If there is space the fastest way to stop a vessel is to make a hard turn. Keep full speed, give full rudder (best effect is if you turn so the propeller effect is helping the turn) until 90 degrees from the initial course. Then reverse engine until stopped. This manoeuvre can not be done in restricted waters, like in a canal or river. In more restricted waters it possible to make repeatedly zig-zag manoeuvres to help reduce the speed. This way you will have a bigger surface area against the direction of movement.
That is an interesting point you have made sir 👍🏻
@@marineinsight I work as a ship pilot and that is a trick I use often.
@@JonasAlexanderson Thank you for sharing your experience and knowledge. Appreciate it. 👍🏻
Short version; use reverse as your brakes, making sure rudder is in straight position, unless you want to change bow direction. Then adjust rudder accordingly. Practice makes perfect!
Yeah practicing word ' viiils ' makes perfect as well, hopefully someday becomes ' wheels '. Tell him....
Thank you sir....I'm a cadet so it's very informative for me and please keep upload videos like this so I can gain my knowledge before joining a ship😊🙌
We are glad that this video is helpful. We regularly share videos on maritime knowledge. Please do Subscribe to our channel and share the video to spread the knowledge 👍🏻
There's common sense but explaining in marine language is very good. Thanks.🙏🏻
Thank you for the comment Avinash. 👍
@@marineinsight
It's Avnish actually. 😭😂 Many people confuse.
Very very informative post... thanks
Glad it was helpful!
Very good explanation sir..tq.. he Manny people's work in commercial ship I mean employees sir
Not *entirely* true that a sudden stop isn't possible, but that is referred to as running aground.
After all, the only thing harder to stop a water craft is stopping a spacecraft.
I'm also old enough to remember how synchro motors that the old engine telegraphs required.
A ship can stop on a dime, it's just that that dime has to be pretty damned big, as in miles.
Unless it has a handy continent to run into, then it'll stop swiftly, but few will appreciate that kind of a short stop.
Excellent video!
Thank you Stephen for sharing your wisdom with us. 👍🏻
Excellent Explained with Animations....
Glad you liked it, please do share and support
Thanks for nice demonstrations.
You are welcome!
Really very good explanation easily understabl. Thank you very informative
Glad you liked it
Very clear explanation..
Won’t reversing the direction of the propeller while moving forward create a vacuum and make the rudder usable and cause a loss of control? This seems dangerous, and I doubt captains would ever stop like this.
Nice video my life first .video
Wow nice. Keep watching.
Great .Extra ordinary video.
Thank you for your comment. Please do share and support 👍
Very Good Explanation 👍
Keep watching
Very informative
Excellent video sir thanks
What you tell drop heavy gravity hooks in sea to stop ship I have heard this trick in my early childhood
When people tells about how to stop a ship immediately other method that is preparation to stop ship are new for me and very knowledgeable
Thanks for this video👍
Thanks for the comment.
never knew this before. thanks for this
Awesome. Glad you found it interesting. Please do share and support 👍🏻
@@marineinsight sure. i will
@@Maheshrpsharma Cheers mate 👍🏻
Tanq sir
Please make a video like everyone understands it ! This is like my physics teacher class in 8-10 std
Sure
Very well and neatly explained.
Thank you Venkat for the comment. Glad you found the explanation useful.
Very informative video.
Glad it was helpful!
Nicely explained. 👌
Glad you liked it
Thank u so much sir for such useful videos..🙏
Glad you liked it. Please do share and support 👍
@@marineinsight yup sure sir..
Thank u
Great video and good information given us.
Thank you. Please do share and support 🙏
Very nice and very informative video!
Sincere thanks for the same!
Awaiting many more like this.
Glad you liked the video and the content. 👍🏻
for the crash maneuvering topic, you have said fuel cam will not change its position due to running direction interlock as per my understanding running direction interlock only stops fuel injection by sending signal to cut out servomotor, it is no where responsible for stopping cam rotation . should'nt it be when we give astern command on telegraph , air distributer cam and fuel cam reverses direction ,but when we give air break fuel will not be injected due to running direction interlock.
my doubt is fuel cam should also turn, please clarify
Indian accent is always vely vely funny 😊😃
:)
Well explained sir
Thanks for liking. Do subscribe and share 👍🏻
Thank you
👍🏻
Very thank to do this type of info's...
Welcome! Please do share and support
Though your explanation is good we could not read the caption as the font of the letter is very very small making it hard to read.
Perfect explain
Glad you think so! Please do share and support
@@marineinsight sure
Wow very interesting to know this by common man Thanks
Thank you for the comment. Ship operations are indeed always interesting for those who are not aware about it. Check this video too--
ruclips.net/video/DSMswMR4UfM/видео.html
I used to live on a 72ft boat, we've never used this crankshaft-reversing method. Newer engines are never directly connected to the prop, a transmission is installed in between which makes it easy and quick to change from forward to neutral to reverse...
not only because it makes it possible for a fixed prop vessel to have its engines running without the prop spinning, but also because most engines and camshafts aren't designed to run in both directions.
Amazing amount of information given
Such an awesome channel !!
@Zaid: Glad you liked the information. Please do share and support 👍🏻
Amazing video sir !👍🏻
Keep watching
Question, if the telegraph control is transfer to ECR.. How could be the air injected, when throotle is set at stop position only.
Hi sir very good presentation.
If it is possible, Please explain about "DRAFT SURVEY".
Noted with thanks
Very interesting message given by you❤
Thank you 🙂
Iam from India Tamil Nadu
Super
Great Senthil. We are glad you liked the video. Please do share and spread the word :)
Do ships employ some sort of flaps such as in airplanes to increase drag?
Hi sir very nice presentation.
Can we use anchor as emergency in moving ship???.
Yes, near coast or port
Can't we reverse the ship at full speed to immediately stop it and when it stops the engine should be kept at stop position, will it work?
When the ship is moving at full speed and to stop it, fuel is curoff....due to the speed of the vessel and the momentum, the engine will keep rotating in the ahead direction till it comes to rest. For immediate stoppage, crash maneuvering is done by applying brake air.
I don't think you need to explain the automobile break because the specific gravity on the land is different than the water and besides ground braking relies on friction (correct me if I'm wrong).
That is true. However, for a layman it is important to visualise what actual brake really does :)
Thanks for the info sir. :)
👍🏻
Thanks
Glad you liked the video. Please do share and support 👍🏻
I have a question for you
What is the procedure of changing direction of a space craft which is in the space and how the thrust work in empty space. According to the Newtons third law of motin.
Can you answer that? We are more into space filled with water :P
Why we need to bring the fuel lever to minimum start setting and why we are again giving the fuel air mixture at last& wht happen if we did not give
Thanks for the nice informative content. What are the conditions that the anchor can failure.
Thank you for your comment.
Anchor can fail if it gets stuck or anchor chain gets tangled up.
Thanks you for giving the valuable knowledge you deserve 1like and 1 suscriber
Hey Parth,
Thank you for your comment. We are glad that the content shared by us is useful 👍🏻
Thank for replying me my friend but the thing and video deserve 1like and subscribe from me best of luck for the next amazing video
Thank you so much my ser. 🌹🌹🌹🌹
Always welcome
Whenever the ship in the jetty and suddenly breaked all the mooring ropes
Then , what will happen?
It will depend on the weather..the end result.
@@marineinsight 👍👍👍
In normal operation, when the engine is shut down in neutral, how much time is needed for the engine to switch from ahead to astern?
As soon as the fuel kicks in, the crankshaft hence the propeller will start rotating in the astern direction, however, due to the momentum of the ship which is still sailing ahead, it will take little time to get it in the aster direction.
@@marineinsight I meant how long does it take for the engine to reverse the firing order....a minute? 30 seconds?
Wow interesting..!!
👍🏻Thank you Sujith. Please do share and support.
@@marineinsight Sure..!!👍
@@sujithkumarjack 👍🏻
Hi please make a videos of converting saltwater to freshwater in ships
@Saravanan: We already have one video on this topic - ruclips.net/video/txziUwXd0cM/видео.html&t
Add ending section of debunking major misconception
There's no truth to that saying,,, you can't teach and an old dog new tricks. I never knew the props turned individually. Not sure how I got here but worth the time to stay. 😃
Glad to know 👍
Bit confusing it is. How the changing firing order will reverse the direction of rotation of engine crankshaft? Suppose it is 4-1-3-2, what will be the order to reverse the direction of rotation? And how it is possible? As pistons are getting fired as usual. It is 2 stroke engine having suction compression and expansion exhaust at a time. For changing crankshaft rotation you have to change the direction of force application on crankshaft.
As you said correo, for change of direction , the direction of force applied on the crankshaft needs to be changed.
The crank webs are scattered at different angles for each unit. Hence, for revesing the direction, those units firing order are choose Whose crank web assist in reversing the engine.
reverse is based on transmission system not mains (crankshaft
Now pulling the lever from full forward to full backwards may act like a disc brake then... Lol 😂
Do ships have gears and gearbox?
Amazing info
Thank you for the comment. Please do share and support 👍🏻
Look up in RUclips the Paul R Tregurtha crash stop.
Done by reversing the pitch of the prop.
OK. 👍🏻 So it was a CPP ship.
NYC bro
Thanks you. Please do share and support 👍🏻
Why drag can not be increased by providing a underwater flaps just like in Aeroplane drag is increased by proving flap on wings.
If we putted the anchor in the water and what happened to nature under the ocean and sea and again how will anchor come up.
There are dedicated anchor points.
So, HOW TO BRAKE? The CAPTAIN DOES NOT REACT. The doctor is with him. I am in charge, I see a lot of controls but I do not know where to start. The rocks are near and I need to break. The people is shouting outside. The port control is talking to me and they say "diminish 25 and head 270 NE". I ANSWERED them: "Good afternoon to you too, don´t forget good manners" Sorry I went out of topic, I talk a lot, that is why the captain lost control...SO, How to Brake?
😂
When making such a good video make sure you do your reserch properly bros
The video is well researched. However, your statement is only correct for a controllable pitch propeller which is not the topic we explained in the video. Hope this clarifies.
Please do check this article for further information - www.marineinsight.com/naval-architecture/controllable-pitch-propeller-cpp-vs-fixed-pitch-propeller-fpp/
With my sailing yacht, in a man over board situation, I shift the gear into idle, and steer a circle. But that will not work so easily with a 500-ft keel :-).
It won't
Have some boats experimented with brake flaps that extend out underwater and push the water
Which technic is more used in modern ships reverse cycle of porpelar or changing the blade direction
@Nikhil: It depends on the system preferred by the owner. As CPP is fairly new concept when compare to FPP, hence we have more FPP ships.
marine insight: most of the boat the bottam using wood but big ship using for steel or wood.if otherwise big ship bottom make steel how to floating in the sea.please can you clear my dought.
Please check Archimedes principle
Power of displacement when any obeject enters in water it displaces water equal to its own mass thus water exterts upwad force on it so if the obeject is denser than water it sinks but jf its less dense it floats . Steel ship floats because of this air inside the ship makes air ship combo less dense than water hence it floats for eg when titanic hit iceberg water statred entring it displacing the air when enough water displaced air and took its place ship water combo became more dense than sea water and it sank
What is the reason behind, when we walking in sea cost we cannot stand the front of stopped ship when the ship stand on the sea for fishing
1.K bye reversing the direction of rotation of propellor is there any stress created on petals of propellors due to moving of ship "i mean while breaking"
2.What will will happen if the ships disel main engine is replaced with electric propulsion system i mean by connecting numbers of motors radially with shaft of propellor this can either save fuel 😅😅😅😅 2 question is it possible
1. The direction is reversed when the engine is completely stopped. If, during emergency, the direction is reversed while engine is in ahead direction, it will incur stress on the engine and shaft.
2. There are ships which are propelled using motors, however to run the motor, the electricity is generated onboard ship by burning fuel. :)
@@marineinsight yaa but using electric propulsion the direction of rotation can be reversed quikly
3. I heard somewhere that boilers is used in ship. what is boiler.? is it used to separate salt from sea water or there is any thing like steam powered propulsion i mean steam engines..?
Hi Abdul
Boiler is used to generate steam which is used in various auxiliary systems such as heating up of fuel, sludge, engine jacket etc.
Please check this video - ruclips.net/video/QHS2qHY8xUw/видео.html
For Converting saltwater into Freshwater, we use Freshwater generator- ruclips.net/video/txziUwXd0cM/видео.html
I know how they stop with no breaks they throw the anchor out!😃
👍
You mean it's like using the hand brake when traveling at 100 miles per hour 😂
In reality ship's have brakes don't they? Opposite thrust?
Yes, not conventional brakes. It is the thrust which acts as one. 👍🏻
Does rudder is used for manoeuvring while going astern?
Hey Rahul,
Have you seen this video of ours.. - ruclips.net/video/k1YxpOg3r6U/видео.html
It will have the answer of your query :)
Please give details about different types of indian coc with different colours.
Thank you for the suggestion Abhilash. We will look into this subject too.
A ship must have large iron plates on the area which is inside the water...these should be constructed in such a way that the remain closed at the time of sailing and at the time of emergency these plates should be open towards outside...
It will be a challenge if there is a wind from behind or ship is in a rough sea.?? 🧐
But these plates must be fitted on side of the ship which remain closed with the body of the ship ...so that their is no impact of wind on it..space should be given on the side of ship so that when these plates were closed, they fit in that space
@@dr-khursheedahmed712 Noted, However, imaging a situation when the ship is in rough sea or wind is changing its direction due to rough weather. Now to stop the ship or during emergency stops, we opened these plates. But instead of increasing the resistance for stopping, it can also assist if the wave or winds is striking the plate from the back !!
Why there is no gear box like other vehicle?
Compare the ship engine vs a car engine. Now imaging the size of the gear box and amount of force required to turn the gear and loss of power...
The easiest way is to reverse the engine or change the pitch of the propeller.
If you put a small engine at bow side its use for dangerous conditions to stop ship problem solve...
Not a practical solution
maybe they can design a flop(like fins of fish), sturdy enough to stop ship within 10 sec.
Which will eventually increase the resistance when the ship is running.
@@marineinsight exactly.
I like your accent haha. Other then that great video!
Thank you for your comment.
This video should have been for only 10 seconds. Upon braking the blade angle changes producing opposite thrust to stop. But good information.
👍🏻
very informative video but change the heading
Please do suggest
6:14 here we see a Phishing Vessel, trying to get your Log-In information.
How does a ship turn?
Glad you asked - here it is - ruclips.net/video/k1YxpOg3r6U/видео.html
@@marineinsight thank you for sharing
Now I am looking forward to find out
What is mt or mv or other different kinds of ships
How hanger will be release
🧐
Explain how anchor fixing sea ground?
What is mv or mt or other kind of ships?
MV is for Motor Vessel (used for dry ships such as container, bulk carrier etc.)
MT is for Motor Tanker (used for tanker ships such as oil, gas carrier etc.)
In emergency situations. When ship is moving forward direction with speed 20 knots. If we drop anchor in to the sea that is enough to reduce the speed or stop the ship
first we need to reduce the ship speed to get faster result (stop). If the anchor rest in the seabed (in areas with less depth), the it will resist the ship movement and help stopping it.
What kinds of fuel used
Now a days, ship uses heavy fuel oil and Low sulphur fuels such as gas oil, lng etc.
They should use in emergency wings for both side to stop ship and reduce speed. Large iron plat
🧐What if the wind is from Behind??
@@marineinsight the wings should be movable vertical and horizontal
@@travelinfoandtech9490 During roough weather when the ships and waves are coming from different directions, it will be hard to use them. Inturn, Sails are now used in cargo ship to assist in propulsion.