In a message dated 96-09-12 21:15:50 EDT, you write:
>Could you provide information on a source for this rope? At N3RS we
>need to replace some of the tag lines we use for hoisting buckets,
>tools, small pieces of antennas, etc. It would be sooooo nice to
>have a line which did not spin like crazy as the load is hoisted. I
>presume that this line does not display the twisting feature I refer to?
Hi, Dave --
Climbing and caving ropes are available from many climbing and caving
stores. Recreational Equipment Inc., Northface, Eastern Mountain Sports,
etc. all have 800 numbers. You may even have one locally. They are
generally kernmantle, or sheathed (sometimes called braid-on-braid), ropes
and will last for years of use. I've been using the same rope since 1985 and
it's probably got 8-900+ tower days on it with only a little wear. You could
even try sail boat suppliers; they offer the same ropes but they don't have
to meet the UIAA climbing/caving standards so they are much cheaper.
As far as tag lines, I prefer 1/4 inch polypropylene. It's cheap and
light and you can cut it up with no qualms. You'll feel sick cutting an
expensive rope. Since it's not going to be permanently installed outside, it
doesn't have to be UV resistant so any old rope will do. You do need to make
an investment in your haul rope, though. Tower Tech has the dacron rope;
it's UV resistant and has the sheath construction for long life; it's perfect
for wire antenna halyards or boom trusses.
The spin of a rope is from the lay or the way the rope is braided or
wound. ANY rope will spin as it is used, some are just more apt to do it
than others. That's another way that makes the kernmantle ropes easy to use;
they tend to be braided and have a neutral lay thus minimizing rope spin.
Another handy characteristic to consider is rope suppleness. That is, is
it soft or hard? Polypropylene is a hard rope and doesn't take a knot
easily. A nylon climbing or yachting rope is soft and will take a knot
easily, which means that it'll hold a knot as well.
One of my old Up The Tower columns in the NCJ was on ropes. It's in the
March/April, 1992 (Vol. 20, Nr.2) issue. Included is a table of rope sizes
and safe working load ratings.
BTW, climbing ropes generally aren't long enough for most tower work.
For a 100 foot tower, you'll need about 225 feet (twice the height plus 25%)
for best results.
73, Steve K7LXC
TOWER TECH -- professional tower supplies and services for amateurs
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