Hi, Karl, after it came down once, I change the support ropes on my G5RV every few years as sunlight gradually makes them brittle, better safe than sorry! I remember in my rock-climbing days we had to change the rope every two years even if it looked as good as new, because nylon ropes lose 40% of their strength in two years.
I only got two SOTA contacts today, Xmas shopping is a b***h!
Brian,
Regarding nylon ropes duration, that’s something I’ve always wondered, as I currently secure my tower with such type of ropes.
I use 3 groups of 4 nylon tie ropes at 3, 6 and 7.5m from the bottom of the tower.
I started doing it when I installed myself the tower in my Aranjuez-Madrid QTH back in 2006.
I had them for about 6 years without any issue, despite the hammering strong sunshine and extremely high temperatures over several months in those latitudes and the below zero night winter freezing temperatures.
When I moved in 2012 to Navarra, my current QTH, and re-installed the tower again here in 2013, I put again the same nylon ropes I had in Madrid because I found them in pretty good shape, except for the 4 nylon tie ropes at 6m from the bottom, which were brand new ones (just in case).
They have withstood pretty heavy winds so far in my current QTH and I’m waiting to see when one of the 8 years old ones will break.
I’ll probably change another of the old groups of 4 ropes next summer, but I just can hardly believe that nylon ropes loose 40% of their strength in 2 years. At least the type of ropes I have.
These are the ones I’m using:
For the group of 4 tie ropes at 3 and 6m from the bottom:
6mm diameter polyester rope by Cordisplay specified for 550 Kgf +5% tensile strength.
For the group of 4 tie ropes at 7.5m from the bottom:
4mm diameter polypropilene nautical rope by Liros specified for 280 daN tensile strength.
Best 73 de Guru - EA2IF
Hi, Guru, I gave up rock climbing thirty years ago when my first kid came along, it didn’t seem fair to a young family to continue an adventure sport! At that time BMC testing showed that a rope exposed to sunlight could lose a significant proportion of its strength with no visible signs of distress. The ropes were 9mm kernmantle nylon (solid core with a woven sheaf), used because they would stretch like a bungee rope under dynamic loading, thus making a fall less of a shock to your body. Polystyrene ropes were used for caving, they had less stretch and were better for lowering loads and prussiking. It would not surprise me if modern formulations of nylon had better endurance but I have no figures on that. I do know that the cheaper hawser-lay ropes sold for home and garden use deteriorate quite rapidly to the point where I can snap them in my hands after a few years, but you get what you pay for and they are much cheaper than a rope that you must trust your life to! I prefer to periodically replace all outdoor ropes (including the XYL’s clothes line!) to be safe.
After looking further into it and why it broke
after been up there since august and old place ones G5 was up for 9 years with no breakages .
It seems cause it does get very windy here being on top of hill and wind coming off the SW at gale force at times me small rope rubbing on top of the roof and rubs it till it breaks has happened
So what ones gotta do is get some thicker rope for first ten foot so it goes over the apex of the house and then size down going down over side that way last a bit longer. did think of 3mm steel rope than thought NO is it will wear the center ridge away very quickly NOT a good idea.
Ideally what one needs to do is get to chimney put a small bracket on it with a pulley and thread it through there making the G5 about 18 inches higher and take the support rope off the apex of the roof.
Talk about panic in middle of a good Sota active day
Can’t be off air noooooooooooooooooooooo
But a good day indeed for welsh and English summits yesterday
But when me beam goes up one be using 4MM steel galvanized rope for that found a good place local on where one can buy good lengths of steel rope in many sizes and types and the other bits required.