tug boats
David,
SNIP
Anybody have any idea of what kind of propulsion system would be on such
a tug?
COMMENT
I expect it was a Voith Schneider drive system which is very popular for harbor
tugs. It has been around for decades. The following is the first few lines of
the Wikipedia listing. You can find many details and diagrams and photos if you
google 'voith schneider'. They are extremely clever
The Voith Schneider propeller (VSP), also known as a cycloidal drive (CD) is a
specializedmarine propulsion system (MPS). It is highly manoeuvrable, being able
to change the direction of its thrust almost instantaneously. It is widely used
on tugs and ferries.
All the best,
Gary Hagstrom
Iron River, Wisconsin
Crackerjack
Mainecat p-47
If the tug is 40 or 50 years old, how it possibly accommodate a Voith
Schneider rig?
Ron Rogers
Ron Rogers wrote:
If the tug is 40 or 50 years old, how it possibly accommodate a Voith
Schneider rig?
A retrofit. I've always wondered how prone to damage the VS are with
the way they hang down under the boat. Aren't they mounted near the
center of rotation. If that's the case, you could use the old main
engine as either a generator or hydraulic pump as the control
mechanism. A little reconfiguration of the after lines and you're
done. But they give you tremendous control and ability to direct full
thrust in any direction, almost immediately. No wonder a number of
older tugs were retrofitted.
John Blackburn
44 DeFever "Yak Rack"
Deale, MD
following from their website
Voith Schneider Propeller (VSP)Over 80 years ago
this ship's propulsion system,
the only one of its kind in the world was
developed by Voith from an idea by the
Austrian engineer Ernst Schneider. It
allows thrust of any magnitude to be
generated in any direction quickly,
precisely and in a continuously variable
manner. It combines propulsion and
steering in a single unit.
This solution is as convincing as it is
straightforward: on the Voith Schneider
Propeller, a rotor casing which ends
flush with the ship's bottom is fitted with
a number of axially parallel
blades and rotates about a vertical axis. To
generate thrust, each of the
propeller blades performs an oscillating motion
about its own axis. This is
superimposed on the uniform rotary motion.
Blade excursion determines the
amount of thrust, while the phase angle of
between 00 and 3600 determines its
direction. As a result, the same amount of
thrust can be generated in any
direction, making this the ideal variable-pitch
propeller. Both variables -
the magnitude and the direction of thrust - are
controlled by a mechanical
kinematic transmission.
with my math 80 is older than 40 or 50
Gary
Hagstrom
Iron River, Wisconsin
Home 715-372-5256
Mobile 925-212-0296
ghagstrom@yahoo.com
From: Ron Rogers
rcrogers6@gmail.com
To: Gary Hagstrom ghagstrom@yahoo.com;
trawlers-and-trawlering@lists.samurai.com
Sent: Wed, May 25, 2011 4:57:52 PM
Subject: RE: tug boats
If the tug is 40 or 50 years old, how it possibly
accommodate a Voith
Schneider rig?
Ron Rogers
80 is older than 40 or 50, but these units do not fit on the bottoms of
conventional round bottom tugs with full-displacement hulls.
http://en.wikipedia.org/wiki/Voith_Schneider_Propeller
The pictures available here show relatively flat bottom sections for
mounting.
Ron Rogers
From: Gary Hagstrom [mailto:ghagstrom@yahoo.com]
Sent: Wednesday, May 25, 2011 7:37 PM
To: Ron Rogers; trawlers-and-trawlering@lists.samurai.com
Subject: Re: tug boats
following from their website
Voith Schneider Propeller (VSP)
http://www.voithturbo.de/sys/images/1pixt.gif Over 80 years ago this
ship's propulsion system, the only one of its kind in the world was
developed by Voith from an idea by the Austrian engineer Ernst Schneider. It
allows thrust of any magnitude to be generated in any direction quickly,
precisely and in a continuously variable manner. It combines propulsion and
steering in a single unit.
This solution is as convincing as it is straightforward: on the Voith
Schneider Propeller, a rotor casing which ends flush with the ship's bottom
is fitted with a number of axially parallel blades and rotates about a
vertical axis. To generate thrust, each of the propeller blades performs an
oscillating motion about its own axis. This is superimposed on the uniform
rotary motion.
Blade excursion determines the amount of thrust, while the phase angle of
between 00 and 3600 determines its direction. As a result, the same amount
of thrust can be generated in any direction, making this the ideal
variable-pitch propeller. Both variables - the magnitude and the direction
of thrust - are controlled by a mechanical kinematic transmission.
http://www.voithturbo.de/sys/images/1pixt.gif
http://www.voithturbo.de/sys/images/1pixt.gif
http://www.voithturbo.de/sys/images/1pixt.gif
http://www.voithturbo.de/sys/images/1pixt.gif
http://www.voithturbo.de/sys/images/1pixt.gif
http://www.voithturbo.de/sys/images/1pixt.gif
with my math 80 is older than 40 or 50
Ron Rogers wrote:
The pictures available here show relatively flat bottom sections for
mounting.
Great pix. I agree with the flat bottom if you are a new building, but
a flat outer skin section faired into the hull lines is what I've seen
done. After lines were made a little fuller and flater. You can do a
lot with steel.
John Blackburn