[TowerTalk] HyGain HG-70HD and Layover Fixture

[Grant Saviers]

Just remember that the loads on a temporary support can be quite large.  
If the support is half-way from the pivot then the entire weight that 
section of the tower is on that support plus the translated moment from 
the beam, mast, and rotator.  For a support further out the weight will 
reduce to half the tower weight with a support at the top and 
substantially reduce the  chance of bending the tower.  Make sure the 
support can't slip.

Grant KZ1W


On 7/6/2014 2:39 PM, Don wrote:
> Up till this year I’ve had a friend down the coast who had a tow truck come up and lay the tower over for me when needed. He retired and sold the truck. So, a friend in the Phoenix area gave me an old layover fixture (given to him) that resembles both the HyGain and TRX-80 fixtures.
>
> I had a local fleet rigging and welding shopup the coast  refurbish and strengthen the fixture. It looks very similar to the current TRX-80 which seems to equipped with a Fulton K1550 winch and 1/4 in cable. My K1550 spare however has a different mounting hole arrangement than that of the layover winch mounting plate on my fixture (so I have two assumptions – the original winch was not a K1550 or the fixture was an early  HyGain - maybe an early TRX?), In any case I’ve adapted of course.
>
> Here comes the question.  The original fixture had a single pulley. I had the shop adapt it to accommodate two pulleys. Since the tower did not have a welded bracket on it for attaching the cable I had the shop make a two pulley device that is held by a 1/4 in cable around the outer tower at about the 8 foot level which appears to be a height consistent with pictures I can find. I calculated that I would need about 60 feet of cable with a double pulley system to do the layover but before I cast this in stone I’d like someone to double check my number.
>
> Because of the lower beam boom length I plan to lay the tower over onto a wooden X frame with a cross-piece at the top, placed far enough along so that the boom of the bottom beam will clear the ground (did this with my Triex WT-51). Then will use a short ladder to get to the mast and rotator etc. The layover fixture for the WT-51 was a 15 foot piece of tubular steel put in the concrete behind the tower. Single pulley and smaller cable since the tower and antennas were less heavy.
>
> I do have some pics of the fixture and maybe someone knows what it was.
>
> Anyway, before I complete this effort (a long long way from anything or anywhere so want to be sure I’ve thought everything thru!!). Any suggestions welcome.
>
> Don W7WLL
>
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