I'm not an expert, but I did tram three 4-el SteppIRs, mounted on TIC rings,
and a Cal-Av 2D-40A, mounted on the bottom of the mast, up my 110' Rohn 55
tower using a similar system. The SteppIRs are only 110 lbs or so with 30'
booms, but they're not very well balanced due to the heavy motors mounted on
the booms. The Cal-Av is 165 lbs on a 16' boom with 75' elements. Your antenna
and tower are considerably larger than mine and may require different materials
and procedures.
All tower work is dangerous, including tramming. My advice is to give a lot of
thought to how you will setup the tram and perform every step of the process,
especially what moves will be required on the tower. Here's what I did:
1. I used a split "trolley" on the tram wire, which consists of two pulley
wheels mounted so that you can slide the sheaves apart to slip the trolley on
the wire. A carabiner attaches to the bottom of the trolley and the attachment
point on the boom. As I recall, I used heavy-duty nylon straps on the boom to
attach the carabiner, and secured the strap with hose clamps to keep it from
sliding on the boom. I used some sort of padding between the hose clamps and
strap to prevent the edges of the hose clamp from digging into the straps.
There may be a better way to attach the tram point on the boom. Maybe some pros
can chime in.
2. I found that it's essential to use a "rudder" attached to the boom. The
hoist rope is attached to the rudder, not the boom. The rudder keeps the
antenna at the angle of the tram wire, so you don't need to attach ropes to the
elements for the ground crew to keep the antenna at the correct angle. I
fabricated my rudder out of a piece of thick aluminum angle stock about 1.5-2
feet long. It's attached to the center of the boom with a U-bolt. The hoist
rope is attached to the other end of the rudder with a carabiner through a hole.
3. However, you may still need ropes thrown over the ends of the boom (not
tied!) to keep the antenna from tilting perpendicular to the tram line. Depends
on how well the antenna is balanced. My recollection is that I didn't need the
ropes. That could have been partly due to using the rudder. You should be able
to get a pretty good idea of whether ropes will be needed while the antenna is
still close to the ground as you begin hoisting. Usually minor adjustment of
the boom mount point will balance the antenna.
4. My anchor point is closer to the tower, I don’t recall offhand where I put
it, but I think it's roughly 200' away. The highest tram point was 110'. This
was fine for getting the antennas over the guys, but to get them over the
highest mounted antenna I had to rotate the TIC ring so the mounted antenna's
boom was perpendicular to the tram, then rotate the boom in its boom-to-mast
clamp to point the elements on the tram side downward and away from the tram
line.
5. I used a 3' screw-in anchor from an AB-577 surplus military mast. I was only
able to get about two feet of it in the ground until it hit ledge. While this
worked, I probably shouldn't have relied on that anchor. When we trammed the
Cal-Av, vibration on the tram line caused the anchor to oscillate slightly and
I could hear the tip of it banging against the ledge. Luckily, it held. I have
to believe that a reasonably heavy pickup truck or larger truck could handle
the weight, would be safer than a screw-in anchor or a tree (depending on the
tree), and has the advantage of being able to adjust the anchor point to get
the best angle for the tram line.
6. I didn't add a temporary guy opposite the tram line. The tram line was
secured to the tower, not the mast, directly opposite one of the tower legs,
the main guys are 1/4" Philly and EHS, and the anchor piers are one size larger
than required -- 6'x3'x1.5', plus quite a bit of extra concrete to fill the
irregular hole. It seemed to me that adding another temporary guy to the main
guys wouldn't increase the margin of safety. I would definitely have done it
had the tram line been attached to the mast.
7. I used a come-along at the anchor rod to lift and tension the tram line. A
vehicle could have been used instead, though I'd still use a come-along for
fine adjustment and to avoid an unfortunate accident. The tram line was
attached to the come-along with a Klein grip so I could adjust the length of
the tram line for each of the four tram attachment points for the antennas at
33', 66', 95' and 110'. A come-along cable isn't long enough to provide that
much adjustment.
8. The tram line was secured to the tower using two heavy duty nylon rigging
straps around each leg just above a cross member and a carbiner through the two
free loops.
9. A pulley for the hoist rope was secured to the tower just below the tram
line using similar strapping.
10. I used a My-Te 300AB electric (AC) capstan winch bolted to the base of the
tower for the hoist rope. It's rated for 800 lb. single line. Same winch I used
to hoist all the Rohn 55 sections, TIC rings, and other heavy items.
11. As your tower is 132' and you are mounting the antenna at 123', you can
secure the tram line above the mount point. If you use a rudder, there will be
a gap between the highest point the boom can reach and the mount point on the
tower or mast. You will need a come-along mounted above the tram line to
support and take the weight of the antenna off the tram line so you can remove
it from the tram line, remove the rudder from the boom and lower the antenna to
the mount point.
(FWIW, I didn't want to secure the tram line for the Cal-Av to the mast, which
is aluminum with a 1/4" wall, so I secured it to the top of the top section and
secured the come-along to the mast. After supporting the antenna with the
come-along, I disconnected the antenna from the tram, the ground man slacked
the tram line, I relocated the tram line below the boom, and hoisted the
antenna up and over the top plate to the mount point at the bottom of the mast.
Pretty tricky for one person with a 165 lb antenna -- had to stand on the top
plate for part of it. But none of that is applicable to your case.)
Hope this is helpful.
73, Dick WC1M
-----Original Message-----
From: Charles Morrison <junkcmp@gmail.com>
Sent: Saturday, September 14, 2019 10:03 AM
To: TOWERTALK@contesting. com <towertalk@contesting.com>
Subject: [TowerTalk] Can you TRAM this ?
Will this work using a TRAM system and not a crane ?
Antenna to raise: 310 lbs x 48ft boom to be installed at 123'
Tower: 132' 55G (130MPH guying) with starguy at 122'
Tram wire: 1/4" EHS
Pulley on tram wire
Tram anchor point: at ground level @ 300ft away from target tower.
Slope: 0.41
Antenna launch point 135 feet away from target tower. (h=0) (165 ft from Tram
anchor point) Attach 1/2" rope to TRAM WIRE PULLEY - up to pulley @ 130ft -
then down to electric rope capstan.
Begin tightening tram wire to slope thereby raising antenna located 165 ft from
target tower off the ground.
Then begin tramming antenna with electric rope capstan.
What weight/mass do I need at the tram anchor point ?
Tree ?
Vehicle ?
Deadman anchor in ground ?
Antenna launch point can not be moved. Lot is too narrow and theres another
tower nearby.
As an alternative, I may a usable tram anchor point 400+ feet away. - I'm going
out to look ant how that lines up now ....
-Charlie N1RR
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