How can such a little tug boat be strong enough to pull such a big ship ?

Question

David j. how can such a little tug boat be strong enough to pull such a big ship ?

Answer 1

You wouldn't call a tug boat small if you looked at the propellors.  There huge and the engine is very big too.   The propellors move a lot of water!

Answer 2

In the water there is much less resistance than on land.  Once movement has started it is easy to keep the momentum and dierect it.  The number of tugs will be determined by the weather conditions working against the movement of the ship.  Things like wind and water currents.  Without those factors it is easy to keep a ship moving with a comparably smaller tug boat.  The times when more tugs are needed are when there needs to be more manuverability (or working against weather).  Using tugs in the right places make it possible to turn the ship without making a several mile loop.  Some ships are equipped with bow thrusters.  Those are basically a built-in propeller in the front of the ship that can move the front of the ship from side to side.  The bow-thrusters aren't made for a lot of power and are often substituted with tugs.

Answer 3

Not as technical as the other answers, but It's what you dont see from above.

Asked same question while walking around a boat repair yard & saw a "small" tug out of the water.

I was amazed by what was below the waterline.

A deep hull for the massive engines & huge propellers.

Answer i got & what everyone else said, it's all  about power, power & more power.

Best regards

Answer 4

Torque -- and a lot of it.

Answer 5

Lots and lots of horsepower.

Answer 6

I am a third mate on a Foss Maritime tug. One of our bouts has 8250hp and massive amounts of torque. Its all about momentum, tug placement, and the line that is used

Answer 7

Tug boats work in teams thats were all the movement comes from other wise A single tug boat has between 700 hp - 3000 hp

thats were it is strong thats like 300 times more hp than a lamborghini and it has a lot of torque

Answer 8

Above are good answers.

Tugboats remind me of the children's story about the little train that could. They may be small, but, they have a big heart.

I have building plans for a small 24 foot tug. It will have less than 100 HP. She may not pull a big ship, but, I bet she will have the heart to push it around some. :-p

Answer 9

"GOB'S of Torque, and they can still get bogged down, you can see them list/twist in the water from the rotation of the engines pulling at max. RPM

Answer 10

Massively strong engine.  As mentioned above, 3,000 to 25,000 HP whereas a 28 foot recreational boat will have 330hp.

Extremely huge propellers.  Like over 10 feet in diameter.  Whereas most recreational boats have a 2 foot diameter prop.

A comparison would be in motorcycles.  A 750cc Honda CB750 engine produces 68 hp, whereas a 600cc Honda CBR600 engine produces 120 hp.

BTW, some tugs aren't little, at 50 to 80 feet long.  But tugs in general are just a floating engine.