Doubling up lines.....

D

David M

Active member
Member
Joined
Mar 5, 2005
RO Number
16492
Messages
7,393
Could someone please define it.

Just got back from the marina.

I think it is supposed to be done in one manner and a lot of folks at the marina thought and were doing it completely different which to me made no sense and offered no additional safety net.

I'll let you know my thoughts after a few responses.
 
Well, it's always meant running multiple lines to as many different attachment points on the dock and boat as possible to me.

Some might say it means just to double up on all the lines you already have going to the boat as you would normally tie it up.
 
I double some and add others to new ties points.
Helps if one fails. So if I lose a pole, then I am still tied to another pole.
If I lose a line, another line is still there.
 
Doubling up? Means you have one line to snap, then another to snap, both of the same force.
Two lines can never be tied at equal lengths, so you really only have two seperate lines, not a larger line made up of two lines.
If you want to beat the force, use a larger line.
 
Kida, I suspect you and I have the same notion of doubling up. Eye over the bollard, made off onboard, then another bight passed around the bollard and made off aboard?
 
NC, I believe you are thinking along my teachings.

My take was always that doubling up meant two separate lines from the pier (dock) to the vessel & vice versa. Many today were running a single line from the dock cleat thru the boat cleat and back to the dock cleat.

To me, if that setup fails, the entire attachment point has failed.

I ran tow separate lines from the boat to the dock/dock to the boat.

My thoughts were that if one separated the other would act as a backup.

I "thought" that was how the large haze grey things did it, however I could be wrong.....It would not be the first time.
 
I assume you are talking about using one line for that? As in tie off to a piling, then to the boat then back out again to the the piling. Or something similar?
 
"Doubling up" I found locally meant running a second line to the same points, each tied off separately.
For hurricane prep this may help a little, but the better "definition" to use in this context would be: Running a second set of lines to different points that will perform the same function.

To truely have a second line of defense, you need to eliminate any common point of failure.

For severe weather, doubling up means adding additional lines to points I'd normally not use. I have a std setup with 8 lines running to poles and to the dock.
(I'm stern in with a fixed dock with 4 piles defining the slip).

Example.. For the spring lines..Fore & aft lines share a midships cleat. During weather, I run an additional line for each that performs the same function.
To backup the primary forward spring lines, I run an set forward from my stern cleat to the midships piling (or to the bow piling if I don't have on mid-ship). An additional set runs from the bow to the stern piling/dock cleat.

This way, if one line/pile/cleat fails, there is another line that will serve the same function.

I had a boat next to me, double up his bow lines using the same attachment points and the stbd cleat let loose. He rubbed on the pile between us the entire storm..
Had he belayed the second line to the port cleat and vice versa, the failure of the stbd cleat wouldn't have mattered as the second line attached to the oposite cleat would have taken the load..

John
 
So Redundancy is a better idea than Duplication.

A critical item is Chafing Gear, as pointed out in another excellent thread.
 
you want to spread the loads to as many points as possible. unfortunately, any boats dont' have enough cleats and most slips dont' have enough pilings and cleats. down in florida, many slips have 3 or 4 pilings on each side, up north where storms are not as frequent you often have only one piling near the bow. another issue is how old are the pilings and how rotted they are at the water line.

havign two lines between the same two points will help in a long lasting storm where the first line may chafe, fail and the second line buys you time.
 
Standard practice with large SHIPS is to pass additional lines from all available shipside mooring points to whatever is available and sensible on the pier. The large "industrial" type ship fittings are all strength-tested during design and installation. I'v never known any that failed. Related to avoiding storm damage the Navy will often send ships to sea well ahead of potential storms. Given some advance track info there is excellent probability of avoiding contact with the storm when driving away at 20 kts for 24 hours.

This present storm is exceptional for its size of the wind area surrounding the eye. The Norfolk ships left early yesterday at the latest en route calm waters off Bermuda or to the south.
 
Thud: forgot to mention you in my answer post. You and NC and others here think as I do and actually more in depth.

I saw a lot of boats who had run lines from the dock cleat through the boat cleat and back to the dock cleat and had already left for the day. I just scratched my head. All mine are separate lines and as Pascal says, not enough cleats on the boat or the dock. There is redundancy wherever possible.

My normal tie up is 5 lines. There are 20 lines and 2 straps there now with redundancy at all points except the bow lines. I was leaning against the boat tying fenders to her an a fellow joked, "I think I saw her move 2 inches!" I figure/hope I'll be OK.

I'll let you know.
I'll let you know.
 
Better hope those piles were driven to resistance or you boat might end up on the hard with the piles still tied to the doubled lines. Secure to multiple points preferably to solid attachment points.
 
quote:
Originally posted by KiDa

T

I was leaning against the boat tying fenders to her an a fellow joked, "I think I saw her move 2 inches!"

Click to expand...


Another problem is if you have to make the lines very tight and can't be around to adjust them as the water rises they can snap, pull out cleats and/or pull out pilings. Or in some cases sink the boat.

That is why a very wide slip or finding a creek to moor off in with the boat spydered off in it works so well. The boat and lines have room to move up and down with the surge.
 
quote:
Originally posted by Capt. Bill1

quote:
Originally posted by KiDa

T

I was leaning against the boat tying fenders to her an a fellow joked, "I think I saw her move 2 inches!"

Click to expand...


Another problem is if make the lines tight and can't be around to adjust them as the water rises they can snap, pull out cleats and/or pull out pilings. Or in some cases sink the boat.

That is why a very wide slip or finding a creek to moor off in with the boat spydered off in it works so well. The boat and lines have room to move up and down.

Click to expand...


My pilings are concrete filled steel. My beam is 11'6". The slip is about 15+' wide. The pluses are the Hurricane has been downgraded to a Tropical Storm for my location and anything that comes is coming from the northeast. Of the 4 boats to block the wind from that direction, the smallest is a 42 Carver.
 
If the slip is tight, run longer lines to points farther away...Gives you a little more vertical room to move without needing a lot of slack...
 
If the slip is tight, run longer lines to points farther away...Gives you a little more vertical room to move without needing a lot of slack...
 
I doubled up on my lines as stated and it worked perfectly. I ended up loosing a stern pole from the dock but because of my redundancy the boat never moved much. I had three aft and three forward spring lines. My shorter stern and bow lines had snubbers on them to accomodate for the tidal urge. They were only about 4 feet long and would not stretch that much.

Come to find out my bulkhead "landlord" recently added the last pole to allow bigger boats, but didn't drive the piling into the mud, they just bolted it to the bulkhead with lag screws !!!!!
 
You must log in or register to reply here.
Back
Top