Extending your anchor rode while anchored

[jclays]

What knot, 5/8 three strand to 5/8 three strand would you use if you where anchored, Ground tackle deployed to it maximum and you needed to add more line to get more scope? Bowline to bowline knots? Adding say another 100ft or so.

[psneeld]

Bowline to bowline.....


Used them exclusively when tying assistance towlines together. Had them melt in place from pulling rather than fail or being unable to untie (except from the melted parts which would happen in almost any knot of hitch where friction happens).

[Comodave]

Back to back bowlines with a safety on each one.

[FWT]

Originally Posted by Comodave

Back to back bowlines with a safety on each one.

Have to ask. What do you mean by a "safety"?

[Comodave]

Bowlines are a great knot but if you want to be absolutely sure that it won’t come undone in a loaded/unloaded situation I use a safety. If it will be under constant load it won’t come undone. But loaded and then unloaded repeatedly it might come undone. Leave the bitter end long enough to put a half hitch around the side of the bowline loop and snug the half hitch tight. That is the safety.

[cafesport]

Rosendahl aka zeppelin bend was created for just that purpose. Easier and faster to tie, won’t jam or slip and easy to untie.

[Dougcole]

Two bowlines would be my choice as well. I would use a double fisherman if I wasn’t going to untie it.

[Comodave]

Originally Posted by cafesport

Rosendahl aka zeppelin bend was created for just that purpose. Easier and faster to tie, won’t jam or slip and easy to untie.

I don’t know about faster. I can tie a bowline in about 1 second with 2 hands. With 1 hand it takes me about 4 seconds. I can tie it behind my back and in the dark just as easily, but then I used to teach marlinspike.

[AlaskaProf]

Originally Posted by FWT

Have to ask. What do you mean by a "safety"?

zip-tie.

[cafesport]

I didn’t teach marlinspike, but like you I can tie a bowline in 1 sec. two bowlines with two securing half hitches is going to take at least four seconds. This bend only takes one second.

[caltexflanc]

As Scott mentioned about the lines melting, you have to be mindful of the chafe factor. You can put a length of some of that velcro-ed chafe protection in each loop, or double up the loops. Having your spare rode rigged with an thimble at one end is another concept and quicker.

A "safety" is achieved via a double bowline knot (not the same things as doing the above).

[Giggitoni]

One of the “bend” knots will usually work well and evenly distribute potential chaffing and load; characteristics two bowlines won’t achieve. Sheet bend comes to mind.

[LovetoBoat]

Originally Posted by FWT

Have to ask. What do you mean by a "safety"?

A Safety Knot - "Stopping the knot is a practice that terminates the end of the rope to the base of the knot. When a knot is tied there will be a tail of rope (bitter end) coming out of the knot (if the knot is an end knot). When the rope is loaded, the end or tail of the rope will want to move back into the knot. If there is not a long enough end, it may enter the knot, causing the knot to unravel. It is common practice to have 8″ to 12″ (20.3-30.5 cm) of the end extending from the base of the knot to which a stopper knot can be tied. The stopper knot is not load-bearing; it is merely a finishing knot to secure the end of the initial knot. If there is plenty of rope coming out of the base of the knot, the knot will be safe with or without the stopper knot. Stopper knots are a good practice, and the stopper knot will also assist in managing the end of the rope from tangling with other components."


This is said better than I could but we use safety knots to ensure the end does not slip and cause the knot to un-knot... often just a half hitch

[DDW]

Zeppelin bend or Carrick bend. Either are more secure that a bowline. Both will be able to be untied even if you break the rode.

[psneeld]

Originally Posted by DDW

Zeppelin bend or Carrick bend. Either are more secure that a bowline. Both will be able to be untied even if you break the rode.

Secure or stronger?

[Giggitoni]

Stronger, and hence, more secure!

[caltexflanc]

I just re-read the OP. Make sure you have both the deployed anchor line and the extension well secured before embarking on joining the two. Consider attaching some sort of float to the original rode in case the join fails if you are the belt and suspender type.

[Simi 60]

If you were prepared in advance a spliced eye with Galv thimble at the ends would be my choice.
Simply join with oversized soft or hard shackle

[psneeld]

Originally Posted by Giggitoni

Stronger, and hence, more secure!

Wikipedia...


"A rope with a bowline retains approximately 2/3 of its strength, with variances depending upon the nature of the rope, as in practice the exact strength depends on a variety of factors."


"Although the carrick bend has a reputation for strength, some tests have shown it to be as weak as 65% efficiency."


Sound pretty close to me....

[jclays]

Double bowline is my choice also leaving long tag ends and tucking them back in several times into the strands of the rope.
Knot chafe not an issue. Knots will be under water.