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brianc 06-03-2013 02:22 PM

Docking with a spring line questions
 
1 Attachment(s)
Hey all,

I've been reading a lot about docking with a single bow aft or midship aft springline and I've successfully done so on several boats, however, I'm having a lot of trouble getting it to work correctly on my boat, a C&C 99 with a Volvo saildrive.

Attached is a deck layout with the position of the dock cleats (yellow lines), position of a pad eye used to attach a block for the spinnaker sheet (red circle with a pink line), shroud chainplate (red circle), stanchions (blue circles), and bow cleat (lime circle.)

I've basically tried attaching springs running aft to the cleat at the end of the dock from all the places listed above except for the bow cleat because I don't have a dock line long enough.

From any of those locations, in light wind, with the wheel hard to starboard (port tie), unless I rev the engine up to ~1800 RPM I don't get enough pivot to bring the stern in to the dock and actually the stern swings away from the dock when I first engage forward throttle. 1800 seems way too high, even taking in to consideration that the rudder is farther aft from the saildrive than it would be on a shaft drive, to be necessary to hold the stern in to the dock.

My slip typically has a crosswind blowing me off the dock which has caused some issues docking so I really want to get this to work better. I would also potentially use a breast line but the cleat on the dock seems like it's too far forward for that to work (it's just slightly forward of the shrouds when she's all the way in the slip.

Any thoughts or ideas? Is the length of the line or attachment point wrong? It doesn't seem like it should be this difficult.

Thanks, Brian

capecodda 06-03-2013 03:25 PM

Re: Docking with a spring line questions
 
I've had boats that spring in well on a breast line, and others not so much. I think the position of the line attachment on the boat matters the most. I'm thinking you need to attach further aft on your boat.

A sail drive might tend to position the prop a little more forward than on a traditional shaft log setup (since the prop can sit almost under the motor). Maybe this also has an effect because you are pushing from a more forward point....not sure, maybe someone with more experience with sail drives can chime in.

Also, the diagram looks like the boat is fairly full aft, so if you think about springing off from against the dock, you cannot pivot as much from amidships as you could in a more traditional design with more taper aft. But I still think it should work if you find the right point on your boat to attach the dock line.

You can experiment without damaging anything by slackening all the lines a bit and trying various breast line positions, until it does what you want when pushing slowly forward.

johnnyquest37 06-03-2013 03:35 PM

Re: Docking with a spring line questions
 
Assuming you are trying to back into your slip:

Come along side one of the piles that will hold the other end of a bow line once you are docked. Not knowing your slip arrangement, let me assume you put your port side to the pile. Attach one end of a line to the pile and the other end to your aftmost port cleat. Center your rudder and saildrive. Put the engine into reverse. The boat should pivot about the pile. You have to slowly ease the line as you back into the slip, and you may have to harden the line and move forward to work the stern in.

brianc 06-03-2013 04:02 PM

Re: Docking with a spring line questions
 
1 Attachment(s)
@johnnyquest37 - I'm trying to go bow in, port tie. Backing in is an option I need to look at though, it would just be a really long trip in reverse down the fairway.

@capecodda - The prop is directly under the forward part of the cockpit so it is definitely further from the rudder than a shaft design. It's probably about 6 to 8 feet in front of the rudder. I attached another pic showing approx where my saildrive is vs the shaft (not my boat, just an illustration.) I'm thinking it has less direct effect on the rudder which is maybe why it requires much higher RPM to hold the boat.

What would the effect of attaching the spring further aft?

bljones 06-03-2013 04:02 PM

Re: Docking with a spring line questions
 
Assuming you are docking bow-in: Your spring needs to be aft of your spinnaker padeye- for a springline to work properly as an "arrestor hook" when looped around the aft most dock cleat when docking, it has to be at, or aft of, the fattest part of the boat.
Enter slip slow, drop spring line over cleat, turn away from dock, throttle up, she'll snuggle right up to the dock- with a wind blowing off the dock, add more throttle after the spring is over the dock cleat.

capecodda 06-03-2013 04:13 PM

Re: Docking with a spring line questions
 
Quote:

Originally Posted by bljones (Post 1039065)
Assuming you are docking bow-in: Your spring needs to be aft of your spinnaker padeye- for a springline to work properly as an "arrestor hook" when looped around the aft most dock cleat when docking, it has to be at, or aft of, the fattest part of the boat.
Enter slip slow, drop spring line over cleat, turn towards dock, throttle up, she'll snuggle right up to the dock- with a wind blowing off the dock, add more throttle after the spring is over the dock cleat.

I think this is correct.


If you attach your spring just to the stern, and power forward, the stern will certainly come in but the bow might start to pull away from the dock. If you attach your spring just to the bow, the bow will certainly come in and the stern will pull away. Someplace between these 2 extremes is a sweet spot that pulls the boat in parallel to the dock.

I'm also thinking that having the prop further forward via the sail drive impacts this balance point a bit, moving it a bit further aft...but not sure about this one.

brianc 06-03-2013 05:16 PM

Re: Docking with a spring line questions
 
So capecodda and bljones...

I was thinking I would turn hard away and the wash on the rudder (wheel away from the dock) would pull the stern in, but it sounds like both of you think attaching the line further aft, powering forward with the wheel turned toward the dock would work better?

johnnyquest37 06-03-2013 05:18 PM

Re: Docking with a spring line questions
 
Quote:

Originally Posted by brianc (Post 1039063)
@johnnyquest37 - I'm trying to go bow in, port tie. Backing in is an option I need to look at though, it would just be a really long trip in reverse down the fairway.

The beauty of warping in like I described is that you don't have to back down the fairway. You go forward into the fairway and then warp into the slip backwards as I described. I do this almost every time I dock my boat.

bljones 06-03-2013 05:22 PM

Re: Docking with a spring line questions
 
LOL- brianc, i am sitting here at work pantomiming docking my desk- it has become such an instinctive maneuver, i had to actually do it to make sure i described it right let me correct my earlier post- throttle up and turn the helm away from the dock, which will drive the stern against the dock.

chef2sail 06-03-2013 05:30 PM

Re: Docking with a spring line questions
 
Quote:

Originally Posted by bljones (Post 1039065)
Assuming you are docking bow-in: Your spring needs to be aft of your spinnaker padeye- for a springline to work properly as an "arrestor hook" when looped around the aft most dock cleat when docking, it has to be at, or aft of, the fattest part of the boat.
Enter slip slow, drop spring line over cleat, turn towards dock, throttle up, she'll snuggle right up to the dock- with a wind blowing off the dock, add more throttle after the spring is over the dock cleat.

BL is right on. I single hand our C&C 35 a lot. The midship cleat placed on the jib track just aft of the widest part of the boat is where my first line loop goes and get dropped around. I have the other line measured and tied around the piling or dock cleat so that even at it fullest extension the bow wont hit the dock box at the head of the slip. It also prevents the boat from blowing back out of the slip or sideways too much. The piling, dock cleat is also aft of the widest part of the boat, but not all the way behind the stern.


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