In article ,
Shen44 wrote:


Subject: Fascinating new drive system from Volvo
From: WaIIy
Date: 12/14/2004 9:56 PM Pacific Standard Time
Message-id:

On 15 Dec 2004 03:37:39 GMT, (Shen44) wrote:

Biggest problem? Forget the possible damage stuff .... for those with twin
screw experience, you'll have to forget everything you learned, be they
inboards or I/O's, and learn a whole new way of boat handling..... and for
many, it will be impossible.

Shen

Good point, it's something new, so it will be impossible to learn.

Duh



BG First off, in reading over the "press release", I'm not sure that this
unit is set up as I first thought. (360* azimuthing).
If, however, it is, then there will be a big learning curve, which some will
never master.
On Z-drives, those who have the greatest problems are generally those who have
a long history of standard twin screw, since you have to throw out everything
you learned, make sure you forget it and learn a totally new system which for
many, never becomes "second nature".

Shen

You can drive this as a standard twin-screw boat around the docks. Leave
the wheel centered and use differential thrust with the gears. My
understanding is that the system does not interfere with this.

--
--
Karl Denninger ) Internet Consultant & Kids Rights Activist
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In article ,
otnmbrd wrote:


Karl Denninger wrote:
In article t,
otnmbrd wrote:


System is being used on many large cruise ships (well, similar) it's
called azipods. as for protection .... hey add some kort nozzles.


There's a HUGE difference between how its done on a cruise ship and this....
--

I don't know that I'd call it a "huge" difference. Unless I mis read,
it's a pod unit which pivots 360 deg and is normally set up to pull
rather than push. Biggest difference I see is that most azipod units on
ships that I know of, have the motor in the pod.

otn

The Volvo system does not azimuth 360 degrees. Its more like an outdrive in
its range of motion, among other differences.

Azipod units also aren't usually set up as "pullers".

--
--
Karl Denninger ) Internet Consultant & Kids Rights Activist
http://www.denninger.net My home on the net - links to everything I do!
http://scubaforum.org Your UNCENSORED place to talk about DIVING!
http://www.spamcuda.net SPAM FREE mailboxes - FREE FOR A LIMITED TIME!
http://genesis3.blogspot.com Musings Of A Sentient Mind

"S. N. Ot" wrote in message
k.net...

"WaIIy" wrote in message
...

http://www.ybw.com/auto/newsdesk/200...42mbynews.html

Tiara is going to use it.

This is going to be a nightmare. Look at the schematic and
read what will happen to the drive under impact.

Yeah - I really want the drive unit to break off and sit
on the bottom.

Are you sure it's not April 1st over in Sweden?



So, what happens when you hit a rock or log at 25 knots with an Alpha or
Bravo drive?

Eisboch

"Eisboch" wrote in message
...

"S. N. Ot" wrote in message
k.net...

"WaIIy" wrote in message
...

http://www.ybw.com/auto/newsdesk/200...42mbynews.html

Tiara is going to use it.

This is going to be a nightmare. Look at the schematic and
read what will happen to the drive under impact.

Yeah - I really want the drive unit to break off and sit
on the bottom.

Are you sure it's not April 1st over in Sweden?



So, what happens when you hit a rock or log at 25 knots with an Alpha or
Bravo drive?

Eisboch

Well when I hit a log at that speed, I lost a blade off the prop and about
3" off the skedge (sp?)

In article ,
Eisboch wrote:



"S. N. Ot" wrote in message
nk.net...

"WaIIy" wrote in message
...

http://www.ybw.com/auto/newsdesk/200...42mbynews.html

Tiara is going to use it.

This is going to be a nightmare. Look at the schematic and
read what will happen to the drive under impact.

Yeah - I really want the drive unit to break off and sit
on the bottom.

Are you sure it's not April 1st over in Sweden?



So, what happens when you hit a rock or log at 25 knots with an Alpha or
Bravo drive?

Eisboch

The nosecone is frequently destroyed or severely damaged, and often the prop
is too. The nosecone and housing, however, are clearly stronger than the
props on this thing!

However, it is on a swivel bracket and the hydraulic rams that control trim
will be destroyed before the unit is completely dismounted, leaving a huge
hole in the boat.

As such you're going to do a lot of damage, but its not all that likely to
sink you.

--
--
Karl Denninger ) Internet Consultant & Kids Rights Activist
http://www.denninger.net My home on the net - links to everything I do!
http://scubaforum.org Your UNCENSORED place to talk about DIVING!
http://www.spamcuda.net SPAM FREE mailboxes - FREE FOR A LIMITED TIME!
http://genesis3.blogspot.com Musings Of A Sentient Mind

Karl Denninger wrote:
Azipod units also aren't usually set up as "pullers".

Azipod is a trade name registered to the ABB corporation. Azipods are
podded azimuthing electric drives, and their design is based on placing
the propeller forward in undisturbed wake for highest efficiency.

You may be thinking of what are called "Z-drives" that are mounted on
tugboats and other small vessels. "Z-drives" are not Azipods but they
are azimuthing thrusters and may or may not incorporate a nozzle.

Rick

On Wed, 15 Dec 2004 17:02:27 -0500, "Eisboch"
wrote:


"S. N. Ot" wrote in message
nk.net...

"WaIIy" wrote in message
...

http://www.ybw.com/auto/newsdesk/200...42mbynews.html

Tiara is going to use it.

This is going to be a nightmare. Look at the schematic and
read what will happen to the drive under impact.

Yeah - I really want the drive unit to break off and sit
on the bottom.

Are you sure it's not April 1st over in Sweden?

So, what happens when you hit a rock or log at 25 knots with an Alpha or
Bravo drive?

I don't think it falls off as this one is designed to do.

Later,

Tom

"Short Wave Sportfishing" wrote in message
...
On Wed, 15 Dec 2004 17:02:27 -0500, "Eisboch"
wrote:


So, what happens when you hit a rock or log at 25 knots with an Alpha or
Bravo drive?

I don't think it falls off as this one is designed to do.

Later,

Tom

I don't know. I've never had the experience, but assume a 15,000 lb boat
doing 25 knots and it hits an unmovable obstruction like a rock ... lemmie
see, energy = mass x velocity squared ... seems to my intuitive analysis,
something's going to give.

Eisboch

On Wed, 15 Dec 2004 18:33:40 -0500, "Eisboch"
wrote:


"Short Wave Sportfishing" wrote in message
.. .
On Wed, 15 Dec 2004 17:02:27 -0500, "Eisboch"
wrote:


So, what happens when you hit a rock or log at 25 knots with an Alpha or
Bravo drive?

I don't think it falls off as this one is designed to do.

I don't know. I've never had the experience, but assume a 15,000 lb boat
doing 25 knots and it hits an unmovable obstruction like a rock ... lemmie
see, energy = mass x velocity squared ... seems to my intuitive analysis,
something's going to give.

You make a good point - I can't argue with it because my experience in
this area is extremely limited.

I've hit things at speed with my outboards and, well to put it
plainly, F'd 'em up pretty bad, but I've never ripped a lower unit off
at speed. Broke a casting once, lost a skeg once and seriously
mangled a prop shaft and prop once.

Then again, neither of my boats weigh 15,000 lbs either.

Later,

Tom

"Short Wave Sportfishing" wrote in message
...

I've hit things at speed with my outboards and, well to put it
plainly, F'd 'em up pretty bad, but I've never ripped a lower unit off
at speed. Broke a casting once, lost a skeg once and seriously
mangled a prop shaft and prop once.

Then again, neither of my boats weigh 15,000 lbs either.

Later,

Tom

When a youngster with a Sears 12' aluminum boat and 7 hp outboard, I seem to
remember leaving the motor unlocked, so if I hit something the motor would
just flip up. (It was embarrassing when you forgot and revved it up in
reverse). Anyway, it just seems to me that a heavy boat at speed isn't
going to stop in time=zero if it hits a rock higher up than the nosecone and
the energy of the impact has to go somewhere. Maybe the leg will stay
together, but the transom will get ripped off.

Eisboch