Jim,
I installed what you described on my 40m tower in 2006. The tower is 33 inches
on a side and 3" diameter legs. The tower has a thick piece of angle welded
across one face at the top and bottom. Both have a large, forged eye bolt
through a hole in the angle. 3/8" EHS cable is terminated to the eye bolt at
the top with a preform. The bottom has a big turnbuckle. I like it.
73... Stan, K5GO
> On Jun 18, 2016, at 12:41 AM, Jim Thomson <jim.thom@telus.net> wrote:
>
> Date: Fri, 17 Jun 2016 14:49:59 -0400
> From: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] Safety line on tower
>
> I see the convenience. They make climbing a 100' tower sooo much easier.
> No guys to hook and unhook to get around and no continuous hook and
> unhook going up and down. More time to work "up there" before reaching
> the time to come down as without the safety line the hook and unhook
> uses a lot of energy going up and down. 100 foot 25G and 45G really do
> benefit from having one. Even 50 or 60 feet. Were I younger and still
> making a good wage, I'd have one on my 100' 45G
>
> 73,
>
> Roger (K8RI)
>
> ## IF the tower in question is just a simple guyed OR free standing tower,
> with NO tic rings OR swinging side gates, the install of a safety cable
> running the
> entire length of the tower should be a simple matter. I have looked at both
> the rohn
> + the Trylon versions, and some others, and they typ consist of a heavy duty
> standoff
> steel assy at the top or close to the top of the tower. The tylon version
> uses what appears to
> be flat spring type steel, in an upside down U shape, sorta like leaf
> spring material, and
> aprx 2-3 inchs wide x 1/4 inch thick. The .375 inch OD EHS cable is
> terminated to one
> end of the U, with either cable clamps or a single guy grip, + the usual
> thimble.
>
> ## Bottom end of the EHS cable terminates to a combo heavy duty spring +
> single
> turnbuckle. The cable itself appears to be spaced aprx 2-6 inchs away from
> the
> tower, usually dead center on one face of the tower. The U shaped spring
> steel
> was designed to offer some form of ... gentle shock absorption. These days,
> with perhaps
> a heavy duty bungee between climbers D ring..and the sliding device, the U
> shaped spring
> steel at top of tower could be disposed of.
>
> ## I suspect that in a lot of cases, the heavy duty spring at the base of
> the tower could be disposed
> of. One turnbuckle would all that would be required to keep the EHS safety
> cable reasonably taut,
> and the bottom termination, of course, would have to spaced away from the
> same tower face
> by a few inches.
>
> ## What Im getting at here is..... I see no reason the entire assy couldnt
> be Home breweded.
> As long as the termination method used at the top of the tower was 100 %
> rock solid, bomb proof,
> I would not hesitate to use such an assy. The cost of the EHS cable, proper
> termination at both ends,
> and the sliding safety device itself would be a minimal, initial investment.
> The sliding devices made
> for the safety cable all seem to be standardized to use .375 EHS cable.
> If joe ham had several
> towers, only one sliding safety device is required. Ok, what I just
> proposed might not be OSHA
> approved, but it would be a helluva better vs free climbing....and less
> fatiguing vs using 2 x lanyards with
> the hook-unhook- hook- unhook scheme.
>
> ## Dunno if the sliding action of the slider will wear out the galvanizing
> of EHS cable..or not. Dunno
> if SS .375 inch winch cable could be substituted..or not. One would think
> that .25 inch safety cable
> would be ample, but I suspect that the .375 cable used has a lot more
> surface area for the slider to
> act upon.
>
> Jim VE7RF
> 0
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