Rigging Spring Lines

[Ron Hotchin]

I noticed a short reference in a past thread to using "spring lines" to help a boat to stand away from a dock and reduce fender chafe. I'm wondering if someone can enlighten me what's needed and how they are rigged. A picture really would be worth a thousand words. smile.gif Thanks.

[DerekW]

Here's a
mooring lines diagram (http://www.westmarine.com/webapp/wcs/stores/servlet/WestAdvisorDisplayView?storeId=10001&langId=-1&catalogId=10001&advisor=550.htm)

cheers
Derek

[Norm Harris]

The simple answer is this; when you make fast to a pier with two lines, bow and stern, your boat is still free to move fore and aft until the boat is brought hard against the pier. In the worst case, this would put one end of your boat back into the fairway where it would pose a hazard to other vessels. Also, your boat would tend to bang against the pier because of the free movement caused by the slack in the bow and stern lines.

Spring lines are belayed from the bow and stern to mid points on the pier or from mid point on your boat to forward and aft on the pier. When properly tensioned, they restrict the fore and aft movement of the boat and protect it from drifting into the fairway or banging hard against the pier.

As the West Marine diagram shows, spring lines will not hold a boat away from the pier. To stand away, you need lines belayed from the side away from the pier to some other point that is strong enough to restrain the movement of your boat. If you are lucky enough to be in a single slip, you can tie your boat to piers both port and starboard. If you are not in a single slip, I think the best you can hope for is to restrict the fore and aft movement.

[ 08-10-2003, 12:46 AM: Message edited by: Norm Harris ]

[Henning 4148]

Not a permanent solution, but something for rough days: If you do not have another point to attach a warp to that pulls the boat from the pier, lay your anchor or kedge sideways from the boat and pull the boat a little bit (half a meter?) away from the pier with the kedge. Make sure the kedge warp is well visible, otherwise you may get to know other very angry boaters.

[Nicholas Carey]

Originally posted by Ron Hotchin:
I noticed a short reference in a past thread to using "spring lines" to help a boat to stand away from a dock and reduce fender chafe. I'm wondering if someone can enlighten me what's needed and how they are rigged. A picture really would be worth a thousand words. smile.gif Thanks.et voilá! Voici, une image pour vous.:

http://www.speakeasy.org/~ncarey/images/docklines.gif

You want the breast lines slack and the spring lines relatively tight because you want to boat free to pitch, but you don't want it able to yaw (rotate so the bow/stern crashes into the dock. It also need to have some degree of freedom to roll, of course.

So...the breast lines are slack, give the boat the ability to pitch (bow/stern rising and falling on the waves).

The spring lines are snug to prevent yaw—if the boat try to rotate into the dock, one spring line or the other will tighten up and prevent it.

The spring lines also prevent for-and-aft motion. With the spring lines snug, the boat can't slide forward or backwards along the dock. Again, the spring lines will tighten up and prevent it.

The spring lines really do most of the work at the dock, not the breast lines.

Hope this helps.

[daddles]

Being a total boating dunce - which is my qualifier for asking a question with an outrageously obvious answer ...

What happens when the tide changes? Aren't your tight lines only going to stay tight for one water level?

Cheers
Richard

[Donn]

In my neighborhood, most of them who tie up parallel to a bulkhead, use whips to hold the boat off the bulkhead, and springs lines to limit fore and aft movement.

You compensate for tidal movement with sufficient slack.

[daddles]

What's a 'whip' and how does it work?

My question about tidal movement was related to Nicholas' suggestion with the tight springs.

Cheers
Richard

[BrianW]

Ah, the joy's of having a slip on a floating dock! Don't have to worry about the tides. smile.gif

If you guys will forgive the picture of my plastic boat (I'm saving $$$ for a larger wood boat!), note the 'spring line' running from the aft cleat forward to the dock.

http://www.imagestation.com/picture/sraid69/p4e6b64aa224809585327a5353d71ee6c/fbadb927.jpg

Since we live in Sitka Alaska, with fairly large tides, I can't imagine trying to deal with a non-floating dock.

[Nicholas Carey]

Originally posted by daddles:
What happens when the tide changes? Aren't your tight lines only going to stay tight for one water level?You're right...after the first tidal cycle, your cleats have been ripped out of the deck after the boat tried to hang on them... :D

If you're stuck on a dock that doesn't float, you have to slack the lines as the tide goes out, and you take the lines in as it comes in.

If you have any kind of tidal range at all, a good set for low tide will be far too loose at high tide and the boat will yaw into the dock.

I don't know what tides are like where you are, but the tidal range here in Puget Sound is upwards of 7 feet (~ 2m). Down at Olympia, Washington, the tidal range is about 14 feet (> 4m).

If you know a good way to tie up a boat at a fixed dock with that kind of tidal range that won't require adjusting the lines as the water level changes, I'm sure a lot of people will be very interested.

[ 08-12-2003, 02:46 AM: Message edited by: Nicholas Carey ]

[Andrew Craig-Bennett]

We have about a 14ft range here. There are several Cunning Wheezes for dealing with the range of tide, of which mooring to a buoy in mid-river is certainly the best, followed by tending your moorings properly, but others include piers with long vertical iron poles on which rings slide - you belay to the rings and with luck the rings will slide on the poles as the tide rises and falls, and, a temporary expedient in fine weather only, hanging weights on the slack lines.

[Oyvind Snibsoer]

Hmmm, no-one mentioned the value of a spring line when approaching or leaving a dock, so here goes:

The spring line is always the first line ashore, and the last to be cast off.

In good time before coming into the dock, make ready a spring line from the bow cleat, on the docking side of the boat. Spliced eye on the dock end, the bitter end is turned once around the cleat and held loosely by a crew member on the bow. The crew member must be ready to let go of the line should things go astray. The dock end hould be approximately half the length of the boat.

Approaching the dock, another crew member jumps ashore with the dock end of the line and makes it fast about amidships of where the boat is intended to be dock. When made fast, the member on the bow holds the spring line tight. Engage the propeller in forward, give a little throttle and full rudder away from the dock. The boat will now nicely close the gap to the dock. Leave the propeller turning and the rudder on full, and the boat will sit nicely until you have fully tied up the boat.

When leaving the dock, the procedure is reversed. Cast off all lines except the bow spring. Engage the propeller in forward and turn the rudder into the dock. The boat will now swing about the spring line, so that the stern points away from the dock. Put propeller in neutral to ease the tension on the spring line, cast off and back away from the dock. It may be advisable to hang your largest fender on the bow, or preferably have a crew member hold it so that it can be moved along the contact point for this maneuver.

If you have a smaller crew, a variation is to just make the spring line a single - "U" - turn around the cleat. The crew member jumps ashore with both ends. The eye is made fast and the member holds the bitter end fast on the dock. The friction of the line aroud the cleat makes this easier than it may sound. It's also possible to use this technique when single-handed, by taking the bitter end back to the cockpit.

For best results, it's usually necessary to use a little more than idle power on the engine, BTW. It's a lot easier than it probably sounds, and using a spring line will make your dockings and departures a whole lot easier and will also make them look a lot more professional. Go and watch the big ships, they always use a spring line when docking.

[ 08-20-2003, 08:07 AM: Message edited by: Oyvind Snibsoer ]

[Donn]

Originally posted by daddles:
What's a 'whip' and how does it work?

My question about tidal movement was related to Nicholas' suggestion with the tight springs.

Cheers
RichardSorry, Richard...I didn't see your question.

Mooring whips are fiberglass rods socketed to the dock, with lines running to bow and stern. The lines on the whips hold the boat just off the bulkhead, and spring lines limit fore and aft movement.

http://www.monarchproducts.com/Gifs/dock/rbslack.gif

[Ian McColgin]

A longer run for springs and bow and stern line solves most of your problem. If you've a 10' tide fall and lay out 30' of line each, there's less than 2-1/2' horizontal change in boat position from high to low. If you're mooring right at low, just make all tight. If not, put a little slack.

If you're moored in a place where there is often and off-pier breeze, you may want to have a loose breast line handy to pull the boat in for boarding.

If you've a permanent berth, you may want the breast lines to go over a pully hung under the dock and to a weight, just to hold her in. Or you may keep a permant line that runs right under the dock, clear of pilings, that's long enough that you're not much affected by the tide.

Good job starting the discussion of using springs, Oyvind. Nordhoff, Nordcross, whatever his name in a hard to find book "The Charter Game" has perhaps the best single description of dynamic springing I've read yet.

I think it well to have a cleat back about 1/4 of the waterline for use as a spring. It is an easier point if you're working the boat ahead and trying to stop about parallel to the dock. If you're springing the stern out, however, you may need to shift to a bow cleat depending on how far you want to twist on your nose.

I've little use for the midships cleat you sometimes see on some of the tupperware boats.

G'luck

[Ian Wright]

Long lines and lots of 'em,,,,,,,
Moored to a pier or dock with a high tidel range use long bow and stern lines taken as far along the dock as you can, at least one boat length from bow or stern, then long springs, the one from the stern leads forwards, the one from the bow leads aft. Try, as far as possable, to keep the stern spring parrallel to the bow line and the bow spring to the stern line. Don't rig breast ropes unles you intend to stay aboard and tend them often.

IanW