Knots

Ok, here’s the scenario…

You are laying line in a system (using British weight line - 5 or 6mm polyprope or nylon) with the intention of meeting up with an existing line to form a T Junction. Once the line is layed it is the intention to leave it there

When you intercept this line, what knot do you use to tie on with?

Using a bowline or other loop type knot would not be tight enough, allowing the junction to move along the existing line. My best guess would be to thread a clove hitch and back it up with a couple of half hitches but this may be problematic in poor viz.

Has anyone got a better idea?

Ta, Steve

[milldog]

haven't got a clue about cave diving but in rock climbing a threaded fig 8 knot would work fine

Graham

[RichW]

I think the placement of the T becomes important here. Is it possible to tie in very close to a main line tie-off so that you can get some tension on the secondary line without "distorting" the main line?

I would think something like a clove hitch as you describe might be the way, as it will be difficult to tension the line with a bowline or something similar, but not impossible.

Rich

[Sheff diver]

If there isn't enough slack in the line you are joining to put a loop, best bet may be to cable tie onto it. Without a loop, I would expect any knot to slip - location and circumstances will determine whether this is acceptable or not. I'd also leave a permanent "out" tag on the shortest / easiest way to surface.

Marcus

Cable ties - Sound like a good idea. Thanks Marcus.

Steve

[Rod]

How about a rolling hitch?
This is basically a clove hitch with an extra initial turn.

Originally Posted by Rod

How about a rolling hitch?
This is basically a clove hitch with an extra initial turn.

Interesting - that would increase the friction and possibly help it stay in place.

[RichW]

I don't know if you guys do this in UK caves, but it's common to mark a jump with two adjacent line arrows. You then tie in between the arrows to stop the line slipping. Could you knock something up like that?

Rich

[Rod]

Before anyone else asks Here is how you tie to.

The Rolling Hitch (Taut Line Hitch)

[Adrian Kelland]

Originally Posted by Rod

Before anyone else asks Here is how you tie to.

The Rolling Hitch (Taut Line Hitch)

Will the additional line be kept in enough tension? If not I don't see how you prevent this knot from coming loose.

A round turn 2 half hitches or similar does not require tension on the added line to stay done up. Arrows either side could stop lateral movement along the existing line.

Adrian