There are standards for when a wire rope should be replaced, one from OSHA
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=34
another at
http://www.grainnet.com/articles/Inspecting_Wire_Ropes-10905.html
As I read this guidance, you absolutely need to replace the cable,
particularly since the breaks are so close together.
Grant KZ1W
On 8/22/2013 12:21 AM, Ray Benny wrote:
I'm in a dilemma.
I purchase a used TM-490 90 ft Sky Needle and recently found some of the
5/16", 7 X 19 aircraft cable lifting cable strands broken. The tower is on
the ground and not been in the vertical position for a number of years. The
problem, apparently there was some gas torch cutting done nearby and
splatter landed on the cable. This molten metal landed on the pull up cable
causing it to burn and sever 2 - 3 strands in one area, and another 3 - 4
strands 6 inches higher up the cable. The cable overall is otherwise in
very good condx with no wear marks. It might have been replaced prior and
the tower has been laying on the ground ever since?
The best and right thing to do is to replace the cable. But, I have been
going through my options:
#1 - Do the cable replacing myself. I have found the cable and cable
pulling grip for less that $200. The major problem is that this is a 3200
lbs tabular tower and not easy to move around. I would need to rent small
boom truck or forklift and some other misc working hardware to pull the
sections apart. It would not be easy, but feel I could do the job.
#2 - Hire someone to come here and do the job. This can run into a 4 - 5
thousand dollar cost.
#3 - Transport the tower to California and have it restring by the tower
company who made it long ago. I've checked commercial transport rates, r/t
shipment and cable replacement cost is more than option #2.
#4 - Do nothing and live with a few broken strands.
*At this point I am looking for thoughts, experiences and/or
semi-professional thoughts on option #4 - do nothing*. I've had a one
experienced tower person say that 6 - 8 broken strands out of 133 is
nothing.
Again, I know the proper/safe thing to do is replace the cable, but how
about doing nothing and using the tower as is?
Tnx,
Ray,
N6VR
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|