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ROHN TOWER GIN POLE

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SBBN

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Jul 29, 1997, 3:00:00 AM7/29/97

I NEED TO FIND SOMEONE IN THE GREATER SYRACUSE, NY WHO HAS A GIN POLE FOR
A ROHN 25G TOWER. I NEED TO TAKE I DOWN (70'). CAN SOMEONE PUT THIS OUT ON
THE NET?

RESPOND TO JIM MOLTION 315 677-5246

Gray Frierson Haertig

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Aug 4, 1997, 3:00:00 AM8/4/97

Easy and cheap to make.

If you are taking down 10 foot sections, a 10 foot 2x4 will work just
fine. Screw or nail a piece of 1 x 4 or a strip of 3/4 ply to the bottom
4 feet to act as a spacer. Drill holes through both near one end for a
U-Bolt and a second set about 4 feet above. Put an eybolt through the
other end and attach a pulley. U-bolt the pole to one of the legs at
the top of the section below the one you are removing. That will put
the pulley about 1 foot above the center of gravity of the next section
up.

If you are doing 20 foot sections, you will need a longer board with a
second 2x4 nailed on edge to the center of the back side to stiffen it.

Avoid taging the removed section too far away from the tower. No sense
in putting any more lateral strain on things than you have to.

Do not attempt to do this if it is windy! Wait for a calm day.

To be very safe, use temporary rope guys on the section immediately
below the one you are removing. It is not safe to climb and work on an
unsupported section of tower as small as 25G.

Happy landings!

Gray

--
Telecommunications Engineering
Gray Frierson Haertig & Assoc.
820 North River Street, Suite 100
Portland, Oregon 97227
503-282-2989
503-282-3181 FAX
g...@haertig.com

Greg Kopp

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Aug 4, 1997, 3:00:00 AM8/4/97

This is just plain nuts. Don't try this. a 2x4? How insane!

I erected a 25G using a home made gin-pole with parts available from a
hardware store and a decent plumbing supply store.

First, from the plumbing supply store, but a 10 to 13 foot piece of
schedule 40, exterior grade, gas pipe. This will be black in color and be
approximately 1.75 inches in outer diameter. They come in different
diameters, a slightly smaller one can work, but will be more flexible. You
want stiffness.

From the hardware store, buy six 2-inch galvanized u-bolts, a heavy duty
pully, some good hemp-type (fiber based) rope or some other type of rope
that does NOT stretch, and a .25inch thick sheet of forged, galvanized
steel. This steel plate should be about 1 foot square.

Next, lay out 4 parallel lines on the steel, on line 1.5 inches from the
edge, the next two inches in from that. The other two line will be a
mirror of these from the opposite edge. Then lay out 3 lines perpendicular
to these 4 lines, one in the middle, and the other two, halfway from the
middle to each opposite side. These will give you drilling points. The
u-bolts will need to go through these holes, so make sure you're
measurments are accurate.

For the gas pipe. Attach the pulley at one end of the pipe, orienting it
so that the rope will pass UP through the pipe, through the pulley, and
then out. I drilled a hole near the top of the mast and attached the pully
with a large bolt and lock washer. This is for safety reasons. If the
pulley breaks, or breaks free, the rope will still be through the pipe. If
the rope were outside the pipe, it would just fall free, creating a
life-safety hazzard.

Now, u-bolt the mast to your steel plate, with the pully oriented at the
top, and the majority of the mast extending BELOW the steel plate. Now at
this point, you can attach a good heavy duty pully near the top of the
tower to help hoist the gin-pole, and you can also drill an extra hole in
the top of the steel plate to put the rope through. Hoist it up, and use
the other three u-bolts to attach the steel plate to one leg near the top
of the second-to-the-top section. Once secure, you can loosen the three
u-bolts on the gin-pole and raise it up. By using 3 u-bolts on the leg,
you have increased safety, and the three u-bolts on the gin-pole are also
for safety, but they also help in raising and lowering the pole. The
friction created helps heep the pole from slipping.

You should also consider putting a good heavy duty pully at the BOTTOM of
the tower and run the gin-pole rope through it. This will allow the ground
crew to use a horizontal pulling force in raising and lowering the tower
sections. It will also keep them from being UNDER the tower during this
operation. SAFETY FIRST.

You're biggest problem will be in seperating the tower sections. Be
carefull you don't bend, break or otherwise damage the cross members, if
you plan on using this tower again. The crimping caused by the tower bolts
can make things very difficult to get apart. At this point I would suggest
some 2x4's be placed accross the rungs of the section below the one you
are taking off, and placing a hydraulic jack on it, with more 2x4's above
it. The trick will be in distrubiting the force equally between all of the
legs. Too much at any one piont can cause damage to the tower.

I took down two 40-foor rohns this way, and erected my own 45 foot and
placed a Hygain EX-14 (14 foot boom, 32 foot elements) on the same tower
without a hitch.

No matter what, SAFETY FIRST. You don'e want to end up in a hospital or
die for a hobby. So when you're up on that tower, make sure you use a good
climbing belt or harness and make sure you are secured to the tower with
at least 3 points, left, right and middle. Hard hats can be a bonus, too.

Plan everything out and you'll be fine. Just don't take any unneccessary
shortcuts.

73 and good luck, Greg KG8O

Gary Coffman

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Aug 4, 1997, 3:00:00 AM8/4/97

On Mon, 04 Aug 1997 01:32:56 -0700, Gray Frierson Haertig <g...@haertig.com> wrote:
>SBBN wrote:
>>
>> I NEED TO FIND SOMEONE IN THE GREATER SYRACUSE, NY WHO HAS A GIN POLE FOR
>> A ROHN 25G TOWER. I NEED TO TAKE I DOWN (70'). CAN SOMEONE PUT THIS OUT ON
>> THE NET?
>>
>> RESPOND TO JIM MOLTION 315 677-5246
>
>
>Easy and cheap to make.
>
>If you are taking down 10 foot sections, a 10 foot 2x4 will work just
>fine. Screw or nail a piece of 1 x 4 or a strip of 3/4 ply to the bottom
>4 feet to act as a spacer. Drill holes through both near one end for a
>U-Bolt and a second set about 4 feet above. Put an eybolt through the
>other end and attach a pulley. U-bolt the pole to one of the legs at
>the top of the section below the one you are removing. That will put
>the pulley about 1 foot above the center of gravity of the next section
>up.
>
>If you are doing 20 foot sections, you will need a longer board with a
>second 2x4 nailed on edge to the center of the back side to stiffen it.
>
>Avoid taging the removed section too far away from the tower. No sense
>in putting any more lateral strain on things than you have to.

I wouldn't trust my life to that rig (and you *are*). Maybe if the 2x4 were
oak or hickory, but definitely not if it is standard construction grade pine.

It is *much* safer to use pipe. 1.5 inch water pipe is fine, but you can get
away with a lighter gauge pipe if you're careful, IE 2 inch muffler pipe.
(Note muffler pipe is given as OD while water pipe is given as ID, both
are about 2 inch OD.) Muffler pipe may bend if you tag out too far, but
it won't split and break like a 2x4.

Drill the pipe near the top for an eyebolt to support the pulley. (The eyebolt
should pass all the way through the pipe.) Double nut it. Down near the bottom
of the pipe, weld on two hooks positioned so that they'll catch the crossbracing
at two levels. Use a nylon tow strap to tie the gin pole to a leg when in use.

Make the pipe about 15 feet long and you have a suitable gin pole for erecting
10 foot tower sections (or removing them). You want to tie onto the section
being hoisted well above its CG so that it is easier for the tower crew to handle
and align on the tower. A 10 foot gin pole can't give you a high enough attachment
point while still having enough material below the standing section to tie onto the
tower securely.

Note that this is an *expedient* gin pole. If the welds are sound and you are
careful, it will do, but it is better to have a real certified gin pole if you value
your life.

>Do not attempt to do this if it is windy! Wait for a calm day.

Absolutely, and make sure your ground crew knows their business, and
aren't distracted by non-workers milling around the site. Don't *ever*
use a vehicle or power winch on the hoist line. Have sufficient manpower
to keep the lines under control at all times. It is far too easy to do serious
harm with a power winch, IE your tower crew can be dragged off the
tower, or if the section snags, you can pull the tower over onto something
or someone using a vehicle or power winch. Do this by hand.

>To be very safe, use temporary rope guys on the section immediately
>below the one you are removing. It is not safe to climb and work on an
>unsupported section of tower as small as 25G.

Absolutely. And *do not* use the gin pole as a way of separating the sections.
It is only for hoisting. Use a bottle jack and a pair of short boards to separate
the tower sections after you remove the leg bolts. If the tower has been up
for a while, climb up the day before and liberally apply Liquid Wrench to all
the bolts, otherwise you'll find them a pure bitch to undo. You may find them
so anyway, so be sure to have a good drift punch handy to drive out the bolt
after you twist off the head. :-(

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