[TowerTalk] Re: TowerTalk Digest, Vol 18, Issue 27

[Mahlon Haunschild]

Anthony,

I agree with everything Dave said.  My old ladder-truss-boom-equipped Rohn
45G foldover is as he describes, including the turning pulley just below
the end of the boom.

I have a complete Rohn 45G foldover manual.  If you can handle large 
files, I can  scan it & send it to you.

regards,

Mahlon - K4OQ
> ------------------------------------------------------------------------
> 
> Subject:
> Re: [TowerTalk] Emergency Rohn 45 foldover help needed!
> From:
> "David Hachadorian" <K6LL at adelphia.net>
> Date:
> Thu, 10 Jun 2004 15:05:57 -0700
> To:
> "Towertalk Reflector" <towertalk at contesting.com>
> 
> 
> ----- Original Message ----- 
> From: "Anthony Kapolka" <kapolka at wilkes.edu>
> To: <towertalk at contesting.com>
> Sent: Thursday, June 10, 2004 10:50 AM
> Subject: [TowerTalk] Emergency Rohn 45 foldover help needed!
> 
> 
> 
>>Hi,
>>
>>I have a Rohn 45 foldover I was hoping to erect this saturday - I
> 
> have
> 
>>a bunch of people coming over to help.  Unfortunately, as I walked
>>through the pieces today, I found a large problem - the fold over
>>assembly does not match the engineering diagram I have!  My diagram
> 
> is
> 
>>from 1981.
>>
>>I must have an older model.
>>
>>The arm terminates in a bracket which has two holes:
>>
>>------------------------------------
>>                                      |         |
>>----------------------------|         |
>>                                      |         |
>>                                      |   O   |
>>                                      |         |
>>                                      |   O   |
>>                                      |____|
>>
>>presumably one is for a bolt/thimble to attach to the winch  and one
> 
> is
> 
>>to attach, somehow, to the tower leg.
> 
> 
> I think you have the old-style boom assembly, like my 1978 version
> Rohn 25 foldover.
> 
> The thimble goes in the hole near the end. When the tower is almost
> upright, you can move it by hand, leaving some slack in the winch
> cable. The thimble will slip past the tower leg, then you jam a bolt
> or clevis pin through the second hole, behind the tower leg, so the
> tower cannot fold over and all tension is removed from the winch
> cable. I think it is a 3/4 bolt or clevis pin. You can put a nut on
> the end of the bolt to keep it from slipping out (although I never did
> put one on mine!). If you use a clevis pin, put a cotter pin through
> the end.
> 
> 
> 
>>The other big question is whether I should assemble this tower with:
>>
>>27' below the hinge and 36' above (which is about what Rohn
> 
> suggests) or
> 
>>37' below the hinge and 27' above (which sounds safer to me - but i
>>have a guy here vigorously arguing I need to follow Rohn's model)
>>
>>I am guying this at the hinge and at the top.
> 
> 
> Do it the way Rohn recommends. There is a LOT of asymmetrical tension
> on the guys wires when the tower is folded over, and 37' (actually
> 39') between the ground and the first set of guys under those
> conditions is probably too much. If it were ok, Rohn would have
> marketed a 74' or 84' version of this tower. The non-approved way
> would also leave your antennas 14' above ground, upside down, and
> interfering with the lower guy wires when it was in the folded
> position.
> 
> Also, with the old-style boom assembly, on the 64' tower, I think the
> Rohn literature showed a pulley, about 10' above ground, just below
> the point where the bottom of the boom comes down to the tower. The
> lifting cable goes through that pulley and then runs vertically the
> last ten feet down to the winch. I've lost my old literature on this
> tower, and am going from memory on this part. Maybe someone with a
> Rohn catalog from the 70's can verify that. If you have a spare pulley
> in the tower parts kit, that's what it is for.
> 
> Dave Hachadorian, K6LL
> Yuma, AZ