Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Other Technical Questions... => Topic started by: Capitaine LaGaffe on August 05, 2012, 03:30:14 pm

Title: Maximizing Maneuverability – Sort of
Post by: Capitaine LaGaffe on August 05, 2012, 03:30:14 pm
Greetings,

Apart from using
1. A couple of Voith-Schneider Propellers (p'hap a ferry style double-ender with one at each end),
2. One or more Schottel units, or
3. Twin screws (I have a contraption with twin screws and steerable Kort nozzles, everything independently controlled – witch tends to confuse my poor brain – so my [stupid] idea is to try something else – possible less taxing for mu brain)
Which provides more maneuverability (assuming a single screw – and probably a bow thruster)?—
A. A Steerable Kort nozzle
B. A fixed Kort + rudder
C. Fixed Kort + Becker rudder
D. No nozzle, becker rudder
E. No nozzle, twin rudders (a lot of the river boats/ship exhibited as models at the SWiss transportation museum in Luzern had a single screw and twin rudders IIRC).
F. No nozzle, plain old rudder.
6. Something else I haven't thought about.

tia/tm
Title: Re: Maximizing Maneuverability – Sort of
Post by: Circlip on August 05, 2012, 04:20:45 pm
Twin Kitchin.

Regards  Ian.
Title: Re: Maximizing Maneuverability – Sort of
Post by: Martin (Admin) on August 05, 2012, 04:29:21 pm
 
Multiple rudders
Bow & stern thrusters
Title: Re: Maximizing Maneuverability – Sort of
Post by: nemesis on August 05, 2012, 05:07:58 pm
Hi, Keep it simple, steering Kort with a slightly elongated rudder. By the time you have mastered that system you can move onto something else, altho you may find that there is no need to do so. Nemesis
Title: Re: Maximizing Maneuverability – Sort of
Post by: Netleyned on August 05, 2012, 05:33:59 pm
Different hull shapes need different ideas.
Becker rudders can be very efficient behind a kort
or behind a big prop.

Ned
Title: Re: Maximizing Maneuverability – Sort of
Post by: Capitaine LaGaffe on August 07, 2012, 07:19:51 pm
Any difference when going astern?
Title: Re: Maximizing Maneuverability – Sort of
Post by: nemesis on August 07, 2012, 07:50:59 pm
Hi, A steering Kort, Yes, very good both ways. A fixed (Towmaster ) Kort is not so good even with the Becker. My opinion and experience only. I can do figure of eights astern with one boat using a steering kort, can not with the other, Keep it simple,
            Nemesis
Title: Re: Maximizing Maneuverability – Sort of
Post by: pima on August 07, 2012, 09:21:59 pm
twin screw twin rudders,on a hydroconic hull you can a tug dance.
   pima.
Title: Re: Maximizing Maneuverability – Sort of
Post by: tobyker on August 08, 2012, 01:11:43 am
Independently driven paddles?
Title: Re: Maximizing Maneuverability – Sort of
Post by: CGAux26 on August 08, 2012, 05:02:20 am
And always, as in "How do you get to Carnegie Hall?  Practice, practice, practice."  O0
Title: Re: Maximizing Maneuverability – Sort of
Post by: Capitaine LaGaffe on August 08, 2012, 07:26:10 pm
Independently driven paddles?
Not very good if you want to go sideways. I have a side-wheeler like that; don't know what a quarter-wheeler is like in practice.
Title: Re: Maximizing Maneuverability – Sort of
Post by: Capitaine LaGaffe on August 08, 2012, 07:42:00 pm
Hi, A steering Kort, Yes, very good both ways. A fixed (Towmaster ) Kort is not so good even with the Becker. My opinion and experience only. I can do figure of eights astern with one boat using a steering kort, can not with the other, Keep it simple,
            Nemesis
Definitely one thing in favour of a single steerable Kort: it's simple. Especially compared to a North American style set up with steering and flanking rudders. KISS indeed!

(Conceptually simple, and something neither my brain nor my thumbs would have much problem with, is a double-ender ferry-style twin-VSP setup, but VSPs are not uncomplicated to set up and the nearest pond is very shallow …)
Title: Re: Maximizing Maneuverability – Sort of
Post by: DavieTait on August 08, 2012, 08:00:38 pm
triple rudder behind a prop/kort combination , being put onto fishing boats up here just now as it maximises bollard pull when turning so would be useful on a tug as well

Title: Re: Maximizing Maneuverability – Sort of
Post by: Norseman on August 08, 2012, 08:08:37 pm
I'd say a couple of new Seals on the rudder http://www.youtube.com/watch?v=vUCBx9zx-UA&feature=related

Dave
Title: Re: Maximizing Maneuverability – Sort of
Post by: nemesis on August 08, 2012, 10:46:10 pm
Hi, Davey, I hope they do not get the nets caught up in that lot, I can remember the clart on when they started to use Korts. My diver friend made a lot of money cutting the nets free. Nemesis
Title: Re: Maximizing Maneuverability – Sort of
Post by: DavieTait on August 08, 2012, 11:01:14 pm
the older boats didn't have enough power in the winch's to haul the gear in when going ahead thats why there was problems initially , the boats now have winches so powerful that they will pull a 200t 21m boat backwards when the engine is in gear and would have been towing the gear at 2knots !!! ( 20t bollard pull minimum per barrel , 3 barrel winches !! )
Title: Re: Maximizing Maneuverability – Sort of
Post by: roycv on August 09, 2012, 10:32:01 am
Hi all, I have a small 28 inches cabin cruiser (Graupner Condor, scratch built from the plans, 50 years ago).  Some years ago I modified it to have a fixed kort nozzle and twin rudders ahead of prop and a single astern. (like the American tow boats).

 I am afraid it made very little difference to maneuverability, it may be because there is not much power there? (6 volts about an amp current).

I was hoping for better control astern.
regards Roy