Rudder size

[bob daily]

I have been looking at various models of RT's and Cutwater's and noticed the size of the rudder. I realize they are designed for more speed than I get out of my R-21, however I would think we all come in to the pier at about the same speed. The bow and stern thrusters are nice but I don't depend on them, and was wondering about maneuverability in tight quarters? Has any one modified or replaced their rudder? If so what was the end result and would you do it again?
Just wondering and day dreaming on a cold winter day! Bob

 

[Romakeme IV]

Bob, good question - and since I'm enjoying my first week of retirement also doing a lot of that winter daydreaming. The only downside I can think of is a larger rudder will put considerable more pressure on the helm at speed as well as its mount points and linkages. Without looking it up I don't remember if the R21 has a shoed rudder or not.? With a single screw I/O close quarters/low speed maneuvering is a pita for me as well.

Regards,

Rob

 

[ALICE J]

I would check Skenes Elements of Design book to get a better understanding of rudders in relation to the hull and propulsion. I know that Nordic Tug had an aftermarket compound rudder that reduced the turning radius.

 

[tlcasper]

We have an R-25 2008 classic and use it on Lake Michigan and Wisconsin lakes. I was never happy with low speed rudder response, especially in marina fairways. After doing some research, I constructed a stainless steel "wrapper" that fits over the bronze rudder. 16 ga. sheet was bent (the bend line is the leading edge) to fit and the trailing edges were bent outward to form a "thistle" shape. The sheath was slid onto the rudder from beneath and bolted to the rudder. The added area was about 33% and has made a big difference in slow speed response. And yes, at high speed, you can feel additional pressure on the wheel, but less wheel movement is required. Backing response is better as well. I'm reluctant to advise this for our saltwater friends because of potential corrosion issues that might arise between the stainless and bronze in contact with each other. So yes, up to a point, more rudder area is a good thing.

 

[knotflying]

I know of a few people that tried to change the rudder size with bad results. Things are engineered, for the most part, with thought, calculations and performance and often a fine balance between all three.

 

[bob daily]

The after market rudder that was offered by Nordic tug's was a articulated rudder. Lots of information on the web about them! Looks like it would be a good fix for the small rudder that are/were being used on the boats with inboards. Yes I know about the engenering, design, and bean counters that come into play when building something. I have seen some captains that rely on the thrusters to dock so much that if they are forced to dock without them they are in trouble!
Just Bob reinventing the wheel one spoke at a time. Bob