[TowerTalk] GM 70' Hazer vs Rohn 70' Hazer towers

[alsopb]

Guys,

I know you guys who believe macho men climb towers, but you too will
get older and start looking for a way to limit your climbing.  Thus,
this discussion is for us who are in that boat-- or anybody else who
doesn't equate tower climbing with his manhood.

For me, the bottom line is the antennas are in the air, operating a
greater percentage of the time.  One doesn't need to get a crew
together to do anything after the initial installation.

Just finished lowering/raising the 4 EL GEM QUAD and 40M rotary dipole
array on my GM 70' HAZER tower.  This was for inspection after the
winter and after some thunderstorms.  It took all of 1 hour (and 2400
hand cranks to do).  Everthing could be worked on while on the ground
or an 8' stepladder.

The 70' Rohn Hazer arrangement takes about the same time to lower plus
a bit to climb to release the lower guys.  

Everytime I do this (it's been at least 15 times in 3 years for
experimention and antenna repairs), I pat myself on the back for
spending the money.  I doubt that things would ever get repaired as
quickly as they break, if climbing was needed.

I recently put up a 70' Rohn 25 tower with a HAZER also.  Perhaps some
of you are interested in the differences.

>From the ease of operation standpoint both are easy.  The GM tower
requires no climbing at all since it HAZER is on a track on the side
of the tower.  The rohn requires one to climb to the 30' level to
detach the guys.  

The GM tower is closer to self-supporting.  The phylistrand guys have
only 120 pounds tension each and use screw in anchors.  The total
downward force of the guys is about 360 pounds under static
conditions. The tower is 16" on a side.  Climbing is not recommended
as someone over 150 pounds in weight will deform the Z braces
somewhat.  The concrete pad required is 4'x4'x4'.  The rating is 15 sq
ft at 87 mph with a 250 pound weight limit on the HAZER.  The tower
came as a complete package. Nothing else to buy.

The rohn 25 tower arrangement was designed for 90 mph at about the
same square footage.  I went mostly phylistrand (t4000) and the rest
3/16 EHS.  It is truly amazing how much more these guys weigh compared
to pure phylistrand.  The total downward guy force is about 1200
pounds under static conditions.  Digging the guy anchor holes was a
real pain and the total concrete (hole + guy anchors) was about the
same.  The rebar cages for the anchors were also a pain to procure and
work around. The rest or the hardware was also considerably heaftier
than on the GM tower. Procurement was by scrounging used stuff
wherever possible.  Of course this tower can be climbed.  Had I to do
this again, I would have gone 100% phylistrand so that whipping the
guys around the beam elements during raising/lowering would be
easier.  The HAZER wraps around the tower and slides on rollers. 

How did the cost work out? GM tower $4200 including concrete.
Rohn 25 tower/HAZER $3100.  All new parts would have raised the ROHN
25 cost.  If I had the extra money, I would have gone GM again.

Now, these towers don't guarantee no climbing ever.  If you rotor goes
and the antenna is pointed the wrong way, you can't lower the HAZER.
This type of failure is a problem with the GM tower since you've got
to loose 50 pounds or find a 140 pound school boy to climb the tower
and orient the antenna.  

Overall, I think these towers (while compromises) provide ME with over
all lower down time.  The emphasis is on ME.  KC1XX could certainly be
able to keep downtime on any tower to a minimum.

By the way, with the GM tower, 70' is the maximum.  One would have to
go to rohn (25, 45 or 55') to go higher with a HAZER.  Of course, one
would have to climb and release at least two sets of guys for these
taller towers.

One has to be a bit careful which antenna one uses.  Some don't have a
big enough slot between an element and the mast/boom mount to decend
around the tower.

By the way, disconnecting guys isn't a big deal.  The GM tower is self
supporting to 50'.  One only disconnects one set of guys at a time.
The Rohn 25 tower still feels solid with just the top guys attached
and the bottom dropped.  You don't do this on windy days.

Be glad to answer questions.

73 de Brian/K3KO

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