[Garry Hartshorn]

I am currently dabbling into a little design project in which we would like to use pod drives. I have the specs from several builders of this type of equipment, but none seems to quite match up with our plan in size and HP rating ( when physicaly the right size HP rating too low ). Just wondering if anyone remembers the 110' Broward Britannia from about 1990 with pod drives and who made them ???

[MacMcL]

Those drives were Ulstein Drives.

[Codger]

Hi Garry
As this project evolves there is one area that has my curiosity piqued.
In a strong following sea the rudder is a critical component. Does an azipod have the same steering authority?

[csa02221862]

Originally Posted by Codger

Hi Garry
As this project evolves there is one area that has my curiosity piqued.
In a strong following sea the rudder is a critical component. Does an azipod have the same steering authority?

Yes and more.They are essentially a rudder WITH power/thrust. They provide steering in any dirrection (swiveling 360 deg) and under any conditions.

Rich

[Henning]

Originally Posted by Codger

Hi Garry
As this project evolves there is one area that has my curiosity piqued.
In a strong following sea the rudder is a critical component. Does an azipod have the same steering authority?

Better even, and with the newer "azi-pulls" it's another level better as well.

[csa02221862]

Pods are offered in several types in two basic groups. ABB Azipods in two types. Large, high power pods for large cruise ships, freighters and tankers. Compact Azipods for smaller vessels, Yachts, ferries and smaller passenger vessels.

For the Recreational boating Mercrusier offers two solutions and Volvo one. Mercrusier offers the Zeus, a true pod and the Axius, a stern drive pusher version. Neither swivel 360deg but use independent control and thrust in two directions to allow the same type of control of a smaller boat as you would have with a full Azipod with bow thruster. They are computer controlled with a joystick for maneuvering or paired together with conventional wheel and throttles for cruising. The Volvo IPS looks like a stern drive traction propeller setup that is bottom mounted like a pod and is similar to the Zeus.

Info and video of all setups is available on YouTube.

Rich

[Ju52]

Originally Posted by csa02221862

Yes and more.They are essentially a rudder WITH power/thrust. They provide steering in any dirrection (swiveling 360 deg) and under any conditions.

Rich

?? any conditions ?? only if the prop runs !?!?

[Henning]

Originally Posted by Ju52

?? any conditions ?? only if the prop runs !?!?

Depends, some pods have nozzles that are more effective with no thrust, though there is always some effect. With twin drives this isn't an issue because you don't shut them down, you just balance counter vectored forces. To stop, I would just point both pods straight out with both engaged and spinning. I have near infinitesimal control of what direction, speed and aspect I want to move at.

[K1W1]

Originally Posted by Henning

I have near infinitesimal control of what direction, speed and aspect I want to move at.

Hi,

You have certainly outdone yourself here Henning.

How much podded drive experience have you really had?

You should be sure of the meaning of words you use before recording them in stone.

http://en.wikipedia.org/wiki/Infinitesimal

Putting both drives straight out I assume means at 90 Degs to path of travel, I am yet to see a propeller designed to be used for forward propulsion that can also work when held sideways to it's designed water flow plane and give anything meaningful in way of thrust.

[Marmot]

Originally Posted by K1W1

I am yet to see a propeller designed to be used for forward propulsion that can also work when held sideways to it's designed water flow plane and give anything meaningful in way of thrust.

That kind is called a paddlewheel or an epicycloidal propulsor.

[Henning]

Originally Posted by K1W1

Hi,

You have certainly outdone yourself here Henning.

How much podded drive experience have you really had?

You should be sure of the meaning of words you use before recording them in stone.

http://en.wikipedia.org/wiki/Infinitesimal

Putting both drives straight out I assume means at 90 Degs to path of travel, I am yet to see a propeller designed to be used for forward propulsion that can also work when held sideways to it's designed water flow plane and give anything meaningful in way of thrust.

About 15 years working Z Drives in the oil field and in ship assist.

[lowelp]

Two boats were built with Ulstein drives- "Fantasy which had 2 fixed pitch drives and Britannia which had 2 variable pitch drives and a third engine running a water jet for increased speed. Britannia burned. Fantasy is still around. Fantasy required a time consuming start up procedure to pressurize the pods with oil before running.

[FISHTIGUA]

Garry,

I take it that you've checked-out the ZF Pod 4000. On their website they say it is good for up to 120 footers but mostly in the 70 to 90 ft market.

One question. What part of having Pod drives is so appealing for your project?

Multipule engine installations? Maneuverability? Pure speed? Space saving?

Answering these questions should help in choosing which system is right for the project.

Cheers

Dave

(I work with IPS often)

I'm thinking th esame thing as Fishtigua, there may be other systems to get what you are looking for.

[Captd13]

The actual name for pointing your drives outward is "Transverse Arrest" and works at 0 thrust just as well at 100 percent. The odd thing with ASD drives is they handle great in a following sea if you have a large skeg on the keel or "boxed keel" but one of my ASD had a tad pole like hull and it swims like one in a following sea. I have Rolls Royce asd with about 3300hp to each. When i am cluched in at 0 percent, there is still enough thrust to dock and is the safest way. so you have to clutch out to truly loose all thrust. if you want to take a look at my vessel it is the Edward J. Moran out of savannah GA