Knots for an existing system
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hi all!
My name is Bretton, I'm an oyster farmer from the Sunshine Coast, BC, looking to switch my grow out system from rafts to Longline to support introducing more polyculture and kelp.
I am relatively new to this world, having only been farming for 2 years, and am looking for some advice. I have an existing grid system with 6x 8000lbs anchors from when this was a fishfarm in the 1980s. I'd prefer to maintain this existing infrastructure to install my new system, but the grid is made with 1 1/4" rope, way to thick for my purpose. I'm planning to sink some of the thick grid lines to keep the system under tension and I want to use 5/8" rope.
So My questions are: what kind of knots should I use to tie a slack 5/8" rope into a 1 1/4" rope under tension? I was thinking a clove hitch spliced back in on itself? Also for my mussel socks and tray stacks, I've been looking at using some prawn clips/caribeaner/snap swivel, and put in two rope locks to stop them from sliding down that make sense? Finally, how far apart should I be spacing the lonelines to ensure they do not tangle with each other?
Thanks in advance for any suggestions!
Cheers
@bretton_hills Hi Bretton, I don't think I completely follow your farm design description. Are you thinking that you would sink the existing grid of 1 1/4" line, under tension, to the bottom, or to several feet below the surface? And are you hoping to use the 3/8" line to grow sugar kelp by stringing this between the existing grided lines?
For the spacing of single line arrays, we typically recommend 40' apart so there's space to maneuver a boat between them, but on a gridded system, you may be able to space the lines closer together. For example, on a 5-line or catenary array, they may be only 2-feet apart. You'd just need to ensure you could access them for seeding, monitoring and harvest without disrupting the surrounding lines.
In terms of connection points -- one option may be to splice in a pigtail connection with a c-link. We use these on the GreenWave farms on the 5-line arrays for lines that have been pretensioned. Then you wouldn't have to address the tension issue every time you went to attach the line. Another option might be to splice in a soft shackle so you have a point to attach and detach even under tension.
To make the connection, it might be worth checking out this lesson and video on using a come along to relieve tension on a system at a specific point. I could see this technique being useful for relieving enough tension to be able to splice in a c-link or soft shackle to the grid lines of your system.
Feel free to follow up with more details if I misunderstood your design. And here's a fun video of Bren and Jill talking about common knots used on the GreenWave farm.