the steering flat

[happy daze john in oz]

Many cruise ships today do not have rudders, The QM2 has the azipods.
and the Amsterdam of HAL, I have just come off has 2 x ABB Azipods 2 x 15.5 MW from 5 diesel generators, Total power 65,000 HP.So No Rudder.
Cheers
Brian

I believe Brian they can move through 180 degrees replacing the need for a rudder. QE3 and Victoria have them also.

[j.sabourn]

#10... The same principles of the outboard on your tinny. Only on a much grander scale. JS

[Ivan Cloherty]

#10... The same principles of the outboard on your tinny. Only on a much grander scale. JS

John the above words are a reflection of the latest development in propellers which are called LAP's (Large Area Propellers), there have been experiments (tank test and shipboard) with these LAP's and they proven to be more efficient than a conventional propeller set up, requiring 13% less motive power, resulting in less consumption than the conventional set up with a propeller within the confines of the hull. These propellers are set aft of the normal hull structure so a protective overhang of the hull has to be built above the water line from which the rudder is also suspended, so it will be a separate steering flat. This system is said to also reduce cavitation which has long been the bane of hull and propeller designers. The largest vessels used so far have been twin 8000 dwt tankers one fitted with the new system the other retaining 'as built' for actual physical sea going comparisons. Another possible side benefit of this system is that the ship's hull may be able to have a fuller form for more of its length thereby increasing its payload capabilities, but alas may increase cavitation which will cancell out any efficiency gained. I thought this fitted in nicely with steering flats and cruise liner discussions above.

[alf corbyn]

i remember seeing a navel launch which had twin linked propellers both had cowls round them the props could be turned which sent the water in the direction they pointed so they didn't need a rudder.