Docking ideas for twin rudder single prop...

[nolatom]

38-footer I'm getting used to, beamy stern, twin rudders, single right-hand prop, with very little prop-walk effect.

Berth is port-side to, on a regular dock face, largish powerboat moored astern, smaller sailboat forward, not a lot of extra room to maneuver in.

Without much prop walk, and with no sideways "kick" from rudders since they aren't near the prop, I've been setting the port shoulder in then a quick forward breast line to hold that, then toss or lassoo stern line to a cleat (and just pull the stern in. Which works, but needs several people (one to make fast forward, one to snare a long stern line, which seems clunky).

Any better ideas? I don't have much fore-and-aft room to use a spring line as a pivot point.

If I were a ship, I'd just use a tug on stbd quarter. But I'm not.

[UNCIVILIZED]

Try contacting TJ D, their boat is a 55' custom, high performance sail cruiser, with twin rudders, & a single MaxProp. Which, a MaxProp would help you some, in that they make it easier to throw & catch the boat. Given that they have so much torque instantly available in reverse. And due to this I'm a big fan, especially when I'm driving race boats where there's no appreciable prop wash over the rudder.

Much of getting into your "slip" will be based on how much room you have in between you & your fore & aft neighbors, along with how beamy they are. So filling us in on that would help. Ditto your boat's dimensions. As well as the prevailing winds where you routinely tie up.

The other thing is that you could politely explain to the particulars of the situation to the folks who run your marina, & ask for a different slip. And possibly speak to your current dockmates about things first or simultaneously. Stating that you're much less likely to have a fender bender if given a different slip. Even if it's just accomplished by moving you to one end of the side tie you're currently on, by way of moving one of the other boats forward or aft.

Have you tried motoring past your slip far enough so that when you put her into reverse, you're moving fast enough for your rudders to give you good steerage. And then turn hard enough so that your stern's aimed where you want it to be when you're parked. Then reversing the rudders so that the bow of the boat then whips into the slip, & is fairly close to the dock at about the time you've totally stopped the boat via the prop.
It's something of a throw & catch version of parallel parking a car. One that's likely easier to demonstrate, & then coach you through live, than it is to explain via text.


Note: I've had a few conversations with TJ D, & a few others on this topic, so if you dig, you'll find the threads in question. As many of the racing boats I drive have the prop half a boat length in front of the rudder.

[nolatom]

The approach in reverse idea is tempting, she almost steers better making sternway. Then I could put a stern spring out, power forward, and lever the bow in.

I'm just not sure I have the guts to try it in the actual spot. The powerboat astern of my space is beamy, hence my stern having to be so wide-off when I approach moving forward.

I'll look for a nice open dock space and try it on for size first. Thanks.

[deblen]

Assuming this is your full time berth:

Consider using a mid ship breast line. Fasten this line to dock & leave it on dock when leaving. Pick it up with gaff when docking & tie it to a midship cleat. Now you are "docked" & can step ashore with your bow & stern lines.

For single handing,Bow & stern lines should be "permanently" fastened to boat. As you return from cruise,set your fenders & bring bow & stern line ends to the area where you normally get on & off the boat & slip knot them temporarily to whatever is convenient.They are ready to grab as you step ashore.

I find it best for single handing to just take a turn around dock cleat & bring bow & stern lines back aboard boat & fasten them. That way,on departure,you can release them from the boat & haul them aboard without leaving boat.
If you use a midship breast line as described,it will hold the boat in place until you release it,chuck it on dock & away you go.

As far as having a single screw & two rudders offset from prop wash,I can't figure why they do that...but I'm not a marine architect

Cheers/ Len

[Stumble]

Generally backing up a boat like this is much easier than bow in, but I would absolutly suggest getting some practice first, dock rash is not uncommon the first couple of times docking them. Bow in you will need to carry a lot more speed than you would like in order to keep enough flow over the rudders to give you stearage. which then makes you somewhat dependent on the stopping power of the prop.

You might want to see if you can find an empty slip on the east side of Pier 1 (where the big boats are) to get some practice before taking her home.

[valhalla360]

Having come from a single engine outboard cat, which was awesome for maneuverability, can see the issue. If I was slow enough that the rudders didn't have effect, I could just turn the motor to direct the thrust. With an inboard, that wouldn't work.

You could certainly add a bow thruster but that's expensive and I'm guessing you are performance oriented based on the boat type you've chosen.

Can you mount a trolling motor on the stern to act as a stern thruster? As long as you pull it up out of the water when not in use, it shouldn't impact performance but will give you some effect similar to prop walk (actually probably better).

Would it be possible to add a removable docking rudder? A simple tiller arrangement that slips into place as you are entering the marina so you have a small rudder in the prop wash. That would give you prop wash over a rudder similar to most monos.

[Lepke]

Sounds like someone made a single screw out of twins w/o doing the rudder. I dock similar to what you have but with twins. However, I do everything at idle and slow, so the rudders aren't too effective. Current boat was built for speed and has small rudders. I mainly use the twins for twisting. As I approach, I'm down to using one engine.
When I dock, I have a spring ready, tied off with an eye on the dock end. I approach the dock at about 15°. I go in and out of gear on one engine so I end up stopped with the bow overhang right over the cleat I want to snag. If solo, I hop out and lasso the cleat and then put the dock side engine in and out of forward to ease into the spring. Once under strain, I put the dock side engine in forward and go down on the dock and grab the already hanging other lines and make fast. I can put my boat into a space with just a couple feet on either end. Less if I have a line handler.
You need to know you have a good line and dock cleat before you leave the boat.

[markpierce]

Lesson: maneuverability if best when the propeller(s) is(are) immediately before the rudder(s).

[Snore]

Assuming this is a modern design with an undercut forefoot, be careful about reversing fast and whipping into the dock. I frequently operate a similar boat and found that once moving the bow can develop momentum and swing past where you want it. That and I am too chicken s]{}t to do a Captain Ron fast approach docking when going along side. Way too many ways for it to go ugly.

Contrary to others, at my boats regular slip each line is left at the dock and the eye is set for easy pickup with a boat hook. Grab the eye with a boat hook, drop it on a cleat and done. Much easier for a single-hander than messing with tying lines to cleats, or lassing pilings. Bow lines, stern lines, and spring lines are each in a different spot, and always left in the same spot.

My former slip was port side down a canal, that required a 180 turn to the dock. Single-handed or crewed, I always landed and secured the windward end first. If the wind was blowing out the canal, I turned the boat a little past 180 deg- so her stern was kind of headed to the dock and eased her stern to the dock. Once I snagged the stern line, I would place it a tad forward of the stern cleat, usually on the primary winch, and ease her into forward with full left rudder. The result was a simple, non-dramatic docking. If the wind was blowing from any other direction, the process would be slight different. The goal was to get the bow on to the dock. Secure the bow line on the bow cleat, and use the spring line (and wind) to pull her in.

Hope all this makes sense.

[Cadence]

Originally Posted by nolatom

38-footer I'm getting used to, beamy stern, twin rudders, single right-hand prop, with very little prop-walk effect.

Berth is port-side to, on a regular dock face, largish powerboat moored astern, smaller sailboat forward, not a lot of extra room to maneuver in.

Without much prop walk, and with no sideways "kick" from rudders since they aren't near the prop, I've been setting the port shoulder in then a quick forward breast line to hold that, then toss or lassoo stern line to a cleat (and just pull the stern in. Which works, but needs several people (one to make fast forward, one to snare a long stern line, which seems clunky).

Any better ideas? I don't have much fore-and-aft room to use a spring line as a pivot point.

If I were a ship, I'd just use a tug on stbd quarter. But I'm not.

All I can do is sympathies with you and suggest having a number of friends.
Sound like you have it down a best I can imagine. Anyone designing a single screw with no prop wash on the rudder should be shot.

[moseriw]

Bowthruster is the only wayvto handle that twin rudder scrap - or speed.

[nolatom]

Bow not really the problem, though

stern thruster is what I need, but no got..

Thanks all for the commiseration and suggestions.

[moseriw]

Originally Posted by nolatom

Bow not really the problem, though

stern thruster is what I need, but no got..

Thanks all for the commiseration and suggestions.

Leaving me curious! Did you ever try to move your stern starbord or port with the bowthruster?

AND I consider the twin rudder scrap as a serious problem for cruisers.
Yes I would like to have twin rudders on an Open 40 racer but certainly not on a cruiser.

[moseriw]

Any better ideas? I don't have much fore-and-aft room to use a spring line as a pivot point.

go in with 1 - 1,5 knots of speed until you reach the point where your bow should be whn berthed, are sure you won't loose to much speed, idle, If the boat is not moving to your needs - correct with bowthruster - once proper inside stop hard with stern about 3 ft away.

Bet it works like a charm.

[UNCIVILIZED]

This manuever's a bit trickier, but... Once you've dropped a stern line onto a cleat on the dock. Then attach one to the dock at about amidships on the boat. With this midships line led through a block on your toe rail, either back to a cockpit winch, or to the capstan on your windlass. And use the mechanical power to snug your boat up to the dock at her beam. Then once she's loosely fixed in place like this, you can attach your full set of docklines, & fine tune her positioning.


Of course this technique assumes the backing in, parallel parking manuver described in my above post. And really, you can put a block anywhere on the toerail which suits you, to pull the boat in, or spring her. Including putting a block on the stem, & winching her bow in snug using either your capstan, or alternatively, a cockpit winch.


Guys, twin rudders ain't going away soon, the GDP thinks they're sexy, & fast. Plus all the cool kids (slick racing boats) have'em. All of which sell boats, so... Marketing typically trumps design, most every time.
Plus on a wide, flat boat, their are only so many options.