ship propeller (elica nave)

[spinbaba]

It's so inefficient when they are light a load.

[POLARTTYRTM]

Put your finger in the propeller

[doserdog]

Why are people scared by this?

[ringapowa9000]

i dont know why, but im afraid of shit like that. and im also im afraid of channel markers wtf???

[highvelocity123]

Did anyone see how high the water line is??...that prop is not under a load unless it's submerged.....it only submerged when weighted down with cargo...

[bagelboi66]

That just seems like a shaft overspeed waiting to happen. Goodbye gearbox!

[sweet58441]

I want to ride on it

[TheMrRedbullrocks]

the only part that scares me

[ElephantRage]

scary as fuck

[Marcomanseckisax]

the screwthrust is thus not axial to the shaft but eccentric, causing upper beariing stress (upward bending of shaft, downward tendency of screw.) At low rpm and short time, not problematic ...

[Rodakgreen]

not very fuel efficient when half the prop is out of the water

[tryithere]

Yhis what's known as a "Tug Of War ter"

[hubertten2]

ale napierdala !!

[Steffen5003]

Das heißt Schraube Mann ey

[TIKIMAN198]

This is like the scene from The Last Crusade when Indy and that jew are arguing in the boat lol

[archuletacanada2012]

i wouldent want to be behind the ships propellers when there spinning it could prouble tear me apart like nothing

[Rimouski418]

Is she headed for drydock?

[spiderstex]

@Rimouski418 I don't think so...

[mackeo22]

stuck in the sand bar?

[spiderstex]

@mackeo22 No. It's just empty :-) it's passing near st. Marco Square, in Venice

[mastersduhgree]

A ships engine is not attached directly to the prop shaft.A ships engine runs a generator and the generator runs an electric motor which provides thrust to the outputshaft.

[hammondsplains]

not always

[tupsumato]

While there are diesel-electric ships, in most ships the propeller is mechanically connected to the engine, either directly or through a reduction gear.

[JacoRosbach]

@mastersduhgree

VERY UNTRUE.......

Most ship run the propellor after a reduction gear.

Some ships run a generator and then the propellor electrical !!!!!

[mastersduhgree]

@JacoRosbach Reduction gear? Then it would mean that the reduction gear is also capable of reversing? The engine runs at such a low RPM it would seem the prop shaft would need to speed up the propellar? Wouldnt it?I have run equipment that operated on the theory i described.I assumed the ship ran under the same principal in order to elevate the shaft speed. Not so then?

[tatyvdc1]

@mastersduhgree OK. Low speed angine No Need reduction Gear. I Am talking abt engine with abt 750-800 rpm. That is realy Too much for the Propellor. Never sailed with Low speed engines, so can not say what rpm they use. !!! To go astern, the engine is not changed at all. Infact from starting to stop on Arrival, always same rpm and engine speed. Propellor blades are turned so that pitch on the propellor is changed. This way the propellor can also go astern, without changing engine.

[mastersduhgree]

@tatyvdc1 Ahhh...would not have guessed that.I operated a 90 ton log stacker(letournou?)And it had a V12 diesel engine which turned a D.C gen and the shaft continued on through the D.C.generator to turn an A.C.alternator(?) The wheel motors(propultion)were variable speed,reversing;were; D.C. The lifting,top clamp and tilt motors were A.C.They reversed but had one speed.After learning the layout of a ships propulsion I thought that they too were reversing D.C motors like the stacker,but no?

[mastersduhgree]

@tatyvdc1 Thanks tatyvdc.Ive just started learning the functions of a ships engine room.It has and is very very interesting(and somewhat complicated)What,can you tell me; is the life expectancy of a mid sized ships engine?(HR.S)?Is there a primer system for initial engine starting?(i cant imagine 100 gallons of staring fluid...heh) The new semi (truck) engines starting system has a primer injector.You toggle the ignition key from off to on and a primer injector pumps diesel into the intake.

[Poisonseed]

Meatgrinder...

[09reddread]

wy is it running for no reason?

[MikeDegen8]

if its new to break in the engine, and possibly just warming up the engine

[tommasometal]

La Panama la vedo sempre quando passo nel Canal dei Petroli per andare agli alberoni ...eri in bacino S.Marco vero?

[brokdaleclosekid]

its a picture of perpellers........

[Hypernl]

I hope there are no fishes swimming there. :D

[huettmr]

who's pulling who?

[paulotmsantos]

The propeller is not under water because the ship must be almost empty...

[dododedy]

it's big mistake ,from engineering spot "

propeller must be work under water level

[rickster9222]

u actually get quite the same amount of power when it is 3/4 into the water aswell as completely submerged in the water. Most of todays ships propellers r 'pods' where the whole propeller moves to act as a rudder and to power the ship which is better than having 2 things do a separate job when u can have 1 thing do both

[tupsumato]

I wouldn't say that azimuthing thrusters are used in most of today's ships. Of course they have become more common over the years, but most ships designed and built in these days still have traditional propellers and rudders.

[Duckyistrippin]

and they can move laterally and in reverse.... reverse is not a capability of most large ships.

[tupsumato]

Most ships with a fixed-pitch propeller are equipped with a reversible main engine.

[jcadlols]

still works like this (less pushing capacity, but is less to push), however on some racing boats they have only semi submersed props to prevent cavitation.

[ragnotgizmo]

Huh?

[gofindjeff]

Looks like a "tug"-o-war...

[stollensecret]

good old fashioned nightmare fuel... the only part of a ship that freaks me out

[Mopolumpu]

Yeas! I have the same fealing too.

[01Gnarkill]

fucked getting near the thing

[mastersduhgree]

@stollensecret Would you explain your statement sir.Sounds interesting.

[stollensecret]

@mastersduhgree lol i mean by watching this im going to have nightmares about being sucked into a propeller... or falling on it... or it chasing me... something like that :)

[mastersduhgree]

@stollensecret Oh gosh.And theres tons of video,s on U tube to erect a dream like that too.

[noxis93]

@stollensecret Isn't it. I adore ships but always get some creeps when seeing a propeller spinning...

[LifeRunner4000]

@stollensecret Id shit myself if i would see this

[MrMillzy991]

@stollensecret same here man i hate the boats propeller its scaryyyyyy

[TJis16]

Wow

That pretty much is my worse nightmate right there.

Summed up-big ships and there propellers.

[50Cent507]

dude i had a near death experience with a ship propeller me and my friend were surfing and we were being dumbasses we went to far out and i think it was either a tanker or a ferry one of those or either it was a tug no it coiuldnt be a tug it was definetly that big well and way me and ryan got pulled or sucked under the ship if u will i tried swimming out to the side of the ship as fast as my arms and legs could but me and ryan were pulled toward the propeller and missed it by and inch.

[taiidan1]

lucky

[50Cent507]

haha yea its scary it is loud and u dunno where da f you are and its freaky!

[avatarfan22122]

dam you are a luck son o a btch! crap that coulda been nasty for you both!! had to be scary as hell

[50Cent507]

yea dude the coastguard hada get us dude ij was out of it. they said i was white as a ghost i looked dead they said and i was just staring up at the sky shaking the whole time ryan was cryingh and spazzing out it was fucking scary as hell dude i aint shittin it was a loud thing to hear too!

[50Cent507]

@avatarfan22122 Oh fuck yeah dude! Not fun I am still in counseling because of it! it HAUNTS me

[off2mianus]

"Engine room, full ahead."

[Yusep27]

Thats funny

[sdrfgvrfgvsfravgdsvS]

is slow!!!

[Gerrit22041992]

isnt so slow, lets try to get in it....

[ingareinar007]

I will try to get another video or pictures of the biggest propeller in the world. In 1982(?) Kawasaki made one that is 11 metres in diameter! Not to sound bigheaded, but sometimes I made blades, and each blade had a weight of 3.6 tonns, and a cost of ca 110 000 dollars.. (we were a team ofcourse, many steps in the production) And when you then have four blades, that is expencive. Then the rest of the system cost like h***. But I did not get % of that :(

[ingareinar007]

Allso should the propellers never be still in the sea, bechause a lot of "dirt" (or what is the word?) will get stuck to the blades, and the propeller vill not perform that well. I can`t really see if that propeller is a monoblock or "screwed" together. Geee they are expensive!! I have made many big blades earlier.. Thanx for cool post! :)

Norway

[laerdal]

The ship has not been trimmed correctly, it is certainly empty but should have taken on ballast to submerge the prop. It is possible that it is very shallow here and needed to reduce draft. There is a lot of stress on exposed propeller blades when running like this. The tug helps the rudder with rear steering assistance.

[spiderstex]

i didn't know this.. thanks! :)

[shadowfax1220]

@spiderstex You can see that the rudder is partially exposed, which will reduce the efficiency of the rudder. Also "prop Wash"or the movement of water over the rudder will be responsible for helping the ship to maintain steerage, perhaps in close quarters movements or windy confitions, The Tug is slowing the ship down, (as it is pulling it back to slow it up) whilst the higher prop speed will allow the ship to maintain high quality steerage and be safer in close to port operations.

[mastersduhgree]

@laerdal What form of ballast can this ship take on.Im unfamiliar with this.Can the ship load water or some other substance to equalize its levelness and putting the prop down into the water?

[xtom1973]

@laerdal

no! this is the new invention called "air prop" (turkey invention ;)

[shadowfax1220]

@laerdal It is Trimmed Correclty, Prop shown is surface prop - look at design of the blades (come to a point) see my other post re reason for Tug also.

[Stingsy]

@laerdal Thanks for summing that up while my slow computer loaded this video.

[maritimefreak]

@laerdal Yes, I agree with you on the point that there is a need to reduce draft. Trimming is incorrect.

[sebaadv]

@laerdal on place there are 12 meters........ 

[enamadoonanontrovoun]

watch CAGATA ANCONA

[freshsi165]

bluddy fuck me i nearly blew my speakers

[ingareinar007]

Hehe, fucking me too. My speakers was bad before this! :) Time to buy new ones here..

[Kiliansels]

yes the tug goes backwards, it's just to control the back of the big vessel.

[JRC808]

i didnt really see but is that tug behind it going backwards...?

[ingareinar007]

The thug is stopping, or keeping that control of the big ship. It looks to me that the big propeller is not thrusting the ship, maybe a little. And propellers must not stand completely still in the sea, a lot of "sea-dirt" sticks easy on the propeller, and then one must polish them with stripes (out of the sea ofcourse). And that is expencive!

[DanArmanno]

you see the rudder and prop cause there is no load on the ship as there would normally be

[bkeys06]

LOL Half of the rudder is showing

[Sipper0]

Oof! I wouldn't like swimming around near there!

[SimulationGuy121]

whoa

[swordfighter3]

its pretty cool to see the propeller spinning

[spiderstex]

Thankyou!!! :)

[ktmakis]

Nice video and ship!

[tylerGo1]

They were probably in shalow water so they were told to dump lots of bllast

[CHRISANTHOS]

why the propeller is out of the water?

[tylerGo1]

They were probably in shalow water so they were told to dump lots of ballast

[giannisk88]

probably because the ship is absoluately empty!!!