Thank you everyone
I thought there might be some Dock Queen Nazi Rule or something but apparently not, so than you for your individual experience.
I am re-reading everything and will make a plan in the next few days. I cant do anything now because its a bit stormy here so I can't measure exactly my current lines
My current lines at too think: 3 strand nylon 25mm = 1 inch. I have 2 long ones and 2 short.
I want to cut the diameter down to 12mm = 1/2 inch, 2 long, 2 short.
Reasons are to fit the winches, reduce weight of the long, reduce diameter so they fit the cleats easier. I will be retaining the old 1 inch lines for stormy use.
I like what people said about the long ones needing to be quite long. often on transient docks the cleats are not at all well placed being designed for a variety of different sized boats. As a solo sailor one can't stuff around when dock crashing... the lines cant be 6 inches short.
I have bow, midships and aft cleats. I often use the amidships boat cleat to take a turn around and run the springs fore and aft from that. So a long line cleated in the middle needs to be able to get to the other end of the boat plus a few feet to tie off/make a bowline.
For my boat at 40 feet the line needs to be 40 foot + midships cleating + 6 foot bow and 6ft stern for cleating = 54 feet?
The short lines 20 foot + 6ft + 6ft = 34feet ? (Currently the short lines are 8 meters = 26 feet)
Type of rope:
3 strand twist 12mm = 2300 kg breaking strain
12 plait hollow braid made of high tenacity polyester 12mm = 3300kg breaking
Price is about the same.
BLACK PEARL POLYESTER - Cousin Trestec - Rope Manufacturer for Industry and Sports
The 1 inch lines should weigh 435 grams / meter
12mm braid 90 grams/meter
So the long ones would be 16 meters, say 8kgs/17 pounds for the 1 inch compared with 1.4kgs/3 pounds for the 12mm. A hell of a lot lighter! So much lighter I will check for a mistake there!
The end point will be 2 long lines adaptable for anything. 2 short lines, but longer than the old ones. Lines much lighter and easier to use, fitting winches and cleats much better. A reserve of older lines for storms, laying up etc.
Only think would be to get some of the lines in a different colour to clearly identify lengths as someone suggested.
Or thats what Im thinking now ....