YCCC Scuttlebutt article from Oct 1994 on calculating the forces involved in a tram system. These are jpg scans of the pages from the issue. IE will display them but the print may be hard to read, you may need to save them to your system and use a graphic viewer or editor to enlarge them.
K1VR collection on how to tram:
I haven't had the chance to edit the following collection of stuff on how
to tram, but here it is, unedited.
On
>
>On a tower-related topic (I have to vindicate myself!)... sure have
>appreciated the info (particularly the archives) on such things as how
>to tram,
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>Does anyone know of any articles on using a trolley-cable
system to put up a beam? We're thinking of using it for a 3-el 40 meter
Yagi.
Hi, Zack --
You've got the right idea but the wrong technique. The
"trolley" or "railroad track" is where you have two ropes or cables and the
antenna sits on top of them. There's a lot of friction in this type of
system as well as antennas bouncing around, etc.
I use a tramming system for about 95% of my antenna installs. It'll
work with guyed towers, trees, etc. In a nutshell, you have a tram wire
attached to the top of the tower and the antenna is slung UNDER the tram
wire on an upsidedown pulley. The haul rope goes through a snatch block at
the bottom of the tower, up through a pulley at the point of tram wire
attachment and down to the load. When you pull the haul line, the load on
the pulley goes up the tramline. It takes about 1-2 hours to rig it but
only about 10 minutes to run the antenna up.
Another advantage is that you can run the antenna
partially up the wire and test it in the air. It only takes a couple of
minutes to drop it down and retune it and run it up again to verify your
change.
There are a couple of subtleties such as tag line management and two-step
lifts that are also involved.
BTW, I have a copy of an article I wrote on antenna
erection that includes diagrams of the tram rigging system. If you're
interested in a copy, send me an SASE or your postal address.
73, Steve K7LXC
============================================================
From: K7LXC@aol.com
Date:
cc:
Subject: Re: Antenna Erection
In a message dated 96-06-19
> Sounds like just what I need to put up a 4 EL DX Eng. 20M monobander
(40' boom). I had planned to use a tram type line attached to the mast
about 5 feet above where the beam will be bolted to the mast. This should
compensate for the distance between the tram line and the boom (lifting
sling and pulley distance). The mast is only 2" x .250 wall so I had also
planned to back guy the mast at the same point that the tram line is
attached thus preventing bending the mast from the weight of the antenna.
What material do you use for the tram line? I was thinking of 3/16" guy
line, but would you trust 1/8"?
Hi, Gary --
Be sure to backguy that thing! Actually I would be hesitant about
going that high up the mast in the first place. My suggestion is to tram
this big antenna up right at the top of the tower; hang it by the bridle to
the tower or lower mast; remove the tram apparatus; NOW re-rig the haul
pulley and haul line up the mast (3 or 4 wraps of a nylon sling choker does
a great job); now pull it up into place. The second lift is dead vertical
and puts no sidepull on the mast. It only takes a little bit longer than
just tramming it but it's a lot safer for your mast.
As far as the size of the tramline wire, I suggest using 1/8 inch
galvanized wire rope or aircraft stainless steel. Anything smaller is hard
to get cable clamps for and the safe working load of it (200 pounds for
galvanized) makes it reasonable for ham antenna tram loads. It's also very
easy to work with unlike stiff EHS.
73 and good luck, Steve K7LXC
A small refinement, with credit to W9LT (or at least he showed it to me).
Rig a short "tiller" of fairly strong aluminum tubing about 3 feet long,
with one end attached to the boom, perpendicular to it and directly under
the tram wire. Attach another pulley to the "tiller", also riding on the
tram line. That way, the beam being raised can't rotate in the horizontal
plane, nor can it rotate around the axis of the boom. Takes all the
excitement out of getting the ends of the elements past the guy wires.
73,
n4zr@contesting.com
I put a heavy eyebolt through the top of the mast, and also hung a pulley
at the same level... the top of the mast is 5' above the tower and the beam
clamps to the mast 1' above the the tower...I ran 3/16 EHS as a tram line,
from the front anchor point at ground level (a BIG tree in my case) 270'
from the base of the tower, up to the top of the mast, then through the
eyebolt and back down to the back anchor at ground level, 90' the opposite
side of the tower base... do not clamp the tram line to the eyebolt, allow
it to creep back and forth through the eye under load to minimize the side
forces applied to the mast... DO NOT use rope for the tram line, as it has
too much stretch, and the tensile load involved when the beam is at the mid
point is greater than you think ( assume that it is 10 times the weight )...
do not make the tram line too steep, the flatter the better... 1.5 times
the height of the tower is a minimum distance for the front anchor... the
back anchor can be closer... anchor points can be trees, ground augers,
trailer hitches on a car/truck, etc...
Then a pulley is installed to roll along the tram line, to act as the car,
and a pull rope is tied to the car and run to the top of the tower, through
the pulley hanging from the eyebolt, and back down to ground level to a
snatch point (about 60' from the tower base in my case) then through
another pulley at this snatch point so that you are pulling horizontally,
when raising the beam... do not tie the pull rope to the beam, you are
pulling the car, and the beam is a passenger only, and hangs straight down
from the car... I used my tractor to do the pulling... watch out for things
getting snagged so you don't snap the pull line or damage the tower... The
pull rope is braided dacron, not twisted nylon...
The beam is suspended from the car with a rope fall (block and tackle), and
is adjusted so that the beam is hanging down the same distance that the
upper pulley is above the tower... The rope fall travels with the beam and
the end of the rope fall has to be in reach of the tower crew when the beam
is at the top, so they can raise or lower the beam during the
installation... (I am raising beams too heavy to be grabbed by hand and
muscled into position)...
You need 4 tag lines on the beam... one at each end of the boom to control
pitching and yawing motions, and one to each side of one (center) element,
about 4' out from the boom, to control rolling motion... run each of these
lines into the center of the boom to tie them off, so the tower crew can
untie and remove these lines after the beam is mounted... where the tag
lines bend/pass over the boom/element they are secured with a single wrap
of black tape, so the tape can be broken with a sharp tug, when removing
the lines...practice this with the beam at head height to get it perfect
before the tower crew has a problem at altitude...
Previsualize, previsualize, previsualize.... picture each step in your
mind, and try to figure out how it can go wrong and what you can do to
prevent that...
Have fun... mine went up smooth as glass in 30 knot winds... looked like
a
747 lifting off..
Denny k8do@aol.com
Date: Thu,
From: David & Barbara Leeson <0005543629@mcimail.com>
To: Towertalk <
Subject: Re: Tramming
There's a diagram of how to do this on page 10-21 of my book. You should
have removable trailing lines on each end of the beam, so it won't rotate
as it goes up and foul the guys. Also, you should be sure that the antenna
center of gravity is below the boom, so it won't tend to turn over as it
goes up.
There's a great pulley you can get at REI, which is about 4" diameter. It
has two independent side plates that are held together with a caribiner
when installed, so you can get it over the tram catenary.
I also build the antenna hanging from the tram, as it gets it up out of the
walking way. And it is easy to pull it part way up to check everything,
and you can also bring it near the tower so you can reach the element ends
to tune the match (I tune the rest of the elements with a hacksaw at
assembly, now that the modelling software has come good, with good scaling
and tapering models, etc.).
Yeah, I use my own taper and element mount models :)
I don't like to use a power winch or truck to pull up anything, as you can
pull the whole mess apart if anything hangs up. Also, I don't like using
hand pulling, because you can drop the works if someone lets go. So we use
hand-cranked ratchet winches (I haven't found a worm-drive winch yet) with
great sensitivity to hangups. When you get the antenna to the mast, it's
easier to release the far end of the tram so the antenna drops down right
next to the mast. Be sure you get the tram and pulling cable on the right
side of the boom for removing or installing!
I use a sailing snatch block at the base of the tower so the winch is
located at the same point as the ground end of the catenary cable, which is
tensioned with a come-along (be sure you know how to release it, so you
don't get caught with too much load at the middle).
Good luck, happy and safe climbing! I go up after the antenna has arrived
at the top, but sometimes you need to guide it.
73 de
============================================================
From: Gary Nieborsky[SMTP:k7fr@ncw.net]
Sent:
To:
Subject: tramming etc.
I have a video of one of my antennas tramming its way to the top. I'll go
dig it out if anyone has interest in seeing a bunch of old coots and one
young buck (me) put up a tower and tram a KT34XA to the top.
Reply direct please.
73
"I don't live in the middle of nowhere, but I can see it from the top of
my
tower."
============================================================
A short length of pipe with its own pulley acting as an anti-roll device,
PERFECT! We use the rope over the ends of the boom for leveling the beam as
it goes up, but the rolling of the boom and element/guy headaches that ensue
has always been a hassle.
This is the only problem we have always had with the trolleys...the antenna
invariably "rolls" a little and the leading tips of the beam invariably hit
the guys. Otherwise this is the only way to go. As previously mentioned by
others the ability to hang a feed line on the antenna and give it a quick
testing, and then easily lowering it to change things is a super plus, but
the joy is only having to attach the beam to the mast when it gets to the
top.
When the forty one foot boom 20 meter beam went up last Fall, as always
an
element tip hit a guy
Date:
From: k4sb@avana.net
Reply-To: k4sb@avana.net
Subject: RE: Antenna Trolly System
CC: cq-contest@tgv.com
Stan, the system I use, which I was taught by others here in the ATL area
and which I have modified is like this.
I connect a STEEL cable about 2' above the antenna to be lowered or raised.
IF the antenna is more than a foot above the top of the tower, I lower it
to that level. The cable is of course secured to the mast. To bring the antenna down, I
have a length of HEAVY chain which I secure about 3 feet out from the
center of the antenna. ( I usually when I build the antenna put heavy duty
eye bolts in these positions. The chain has safety belt clamps which merely
clip onto the eye bolts. The center of the chain has a heavy duty ( rated at 480 lbs---
destruct level over 2000 pounds---made by Deuel Manf. ) pully which is
treaded onto the cable and the normal mount of the pully connects to the
center of the chain.
I mount another pully ( using muffler clamps above the 2' point, and have
one directly at the base of the tower. I use medium duty ( > 500 pounds
breaking point ) nylon line, run it through the tower base pully to the
tower mast pully,
and connect to center of chain. Next I tension the far end of the cable
with my pickup truck, or to a BIG tree. Use a "come-along" but don't get
carried away. The base pully rope goes to my Toyota Tractor....Dismount
the antenna and the weight and all are transferred to the cable. Down the
tower and either pull on the the rope ( if the antenna is on the ground )
or start out about 150' away and drive toward the antenna. Rope goes
through pully, gravity starts antenna
down and hopefully, you will have the antenna at ground level before you
hit the tower with the tractor. Incidentally, somewhere on the cable at
about the 20'
point above ground...I put a couple of cable clamps to form a stop. After
the antenna is down, I loosen the cable and the antenna comes gently to
ground.
I do this by myself, and it usually takes about an hour....up or down. BE
SURE the cable pulls against a guy OR install a temp guy opposite the
pully. ( except
for light antennas...say up to 75 pounds. )
I'm sure some of the other guys can comment or add to this. Good
luck...Also works out fine for testing the antenna and tuning it before
you
permanently install it...
73, Ed
-------------------------------------
Name: ed sleight
E-mail: k4sb@avana.net
Date:
From: rattmann@cts.com (Rattmann)
Subject: Tramming
Cc:
Hi Jim,
Enjoyed your info on the tram line experiences. As I watched this thread
the past few days, most of the fine points have been covered by others,
although this subject is best covered in a magazine article where photos and
drawings can tell a thousand words... but I did want to add one thing which
I haven't seen covered. N6ND and I together have trammed up perhaps 150
antennas for ourselves and others over the past 25 years, so we've had a few
knocks! As you suggested, one of the biggest problems is 'rolling' of the
boom, which causes the element tips to go 'high or 'low' relative to the
slope of the guy wires you are trying to avoid near the tower top. Another
is the tendency of the boom to wander in the horizontal plane, so that your
reflector (or last director) element tip may arrive at the mast area before
the boom-to-mast plate gets there (this can be minimized by use of
lightweight tag lines controlled by ground people but is not always
satisfactory).
The fix for both problems is the following. Use a bridle to hang the boom
about three feet below the upside-down traveling pulley. Of course, the
boom should be normal to the direction of the tram wire, with the element
tips pointing at the target tower and elements parallel to the earth.
Adjust the bridle position carefully over the c.g. for best boom balance to
keep it level. At this point, most people tie their haul-line either to
the boom itself, or to the traveling pulley. Either method causes the problems!
The solution is to use a 'torque arm' on the lower end of the haul line.
The arm is made of a piece of angle iron, 1/8-inch by 1-inch by about 28
inches long. Drill one end to accept a shackle for the haul line. Drill
the other end to accept a single HD muffler clamp for the boom in use. With
the antenna hanging on the bridle a few feet off the ground, and the boom
balanced end-to-end, put the muffler clamp and torque arm onto the boom,
next to one or the other edge of the boom-to-mast plate, which keeps it near
the c.g. point.
The torque arm points at the target tower. You will find that you can set
the 'angle of attack' of the elements by swiveling the arm and tightening
the muffler clamp wherever you want it. In general, with a tram system you
want the leading tips of the elements to be perhaps 10-15 degrees above the
angle of the tram wire itself. This keeps them out of the upper guy wires
as the beam approaches the tower top, but not angled so high that they
collide with another beam which might already be up ten feet on the mast.
In most cases I have found that putting the torque arm in approximately the
same plane as the elements is about right (sometimes a bit below their
plane is best). KLM antennas in particular need the torque arm, because
they are so top-heavy and want to roll over, backward, without it. In any
case, try a few short test lifts part way up the tram and keep adjusting
the torque arm until you get the angle-of-attack right.
With a rigid torque arm at the base of the haul-line you will find that the
boom cannot roll over, nor will it wander in the horizontal plane even with
a bit of wind blowing. The rigid arm keeps the boom perpendicular to the
tram (and thus the elements remain parallel to the tram, which means they
won't try to cross over the tram and get hung up). These features make
taglines unnecessary, and one-man installations are possible. I hang a
come-along from a mast clamp about five feet above the target location.
When the upper end of the torque arm arrives at the mast, I reach out and
attach the come-along lower hook to the boom bridle and pick up the load.
Then the lower end of the tram can be slackened and removed, and walked in
toward the tower. Then the upper tram area is dismantled and the boom
plate fastened to the mast, positioned by the come-along.
BTW, if you do a few of these you should make a permanent wire rope bridle
which terminates on short angle-irons with a muffler clamp in each to fit
the boom. You can move the boom back and forth through the clamps to
quickly find your balance point and then tighten them. Nicopress a big
thimble in the middle for shackling, etc.
This has gotten a bit long but hope the torque arm description will be
useful to some of the gang who use tramming systems.... 73!
Glenn K6NA
Hello, tramline fans --
The "tiller" pipe is a new one on me but a clever (and automatic)
solution to a typical antenna's propensity to turtle (roll over) and to get
it over the top set of guy wires. Here's a couple of related thoughts.
One method is to use a tag line that was described in excellent detail
by K8DO. I use this technique to tip the elements to near vertical as the
antenna approaches the top set of guys and even branches for tree
installations. You don't have to remove the top set of guys to get the
antenna up. Use of tag lines gives you more control of the beam
attitude.
The other thing that may help is to mount the elements BELOW the boom
instead of on top. Why are the mounted on the top anyway (KLM, homebrew,
etc)? You're fighting gravity and the darn thing can turtle, or pitchpole,
on you. Force 12 antennas mount the elements below the boom and it sure
makes sense to me.
73, Steve K7LXC
when using a tram line here i clamp a short (3' or so) pipe to either the
boom or boom-mast plate depending on where there is room. this is set so
it points up and has a rope tied to the top of it. this way while the tag
lines can be used to control side to side motion this line can be used to
tip the elements as the antenna approaches the tower to clear guy wires.
this has worked great for raising
a 6 ele 20m telrex to 150' and an 8 ele 15m telrex to 120' here. (pictures
available on my web page of antennas, but not tram setup yet)
73, dave
--
ky1h@berkshire.net or robbins@berkshire.net
http://www.berkshire.net/~robbins/ky1h.html
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Date:
Subject: Summary/Cookbook-Raising Antennas
Ladies and Gentlemen,
I ask for a "cookbook" method raising large antennas several weeks ago.
This is a summary of my cookbook with some notes, options, opinions and
addendums. Credit is given where credit is due, even if it is not original
but experiential. This might not be exhaustive or even clear, but it sure
helped me envision how I am going to put up the TH6DXX this spring.
E-mail your comments to k0wa@southwind.net, but don't include all this
information in the reply. Don't take up the bandwidth.
Raising a Beam to the Top of the Tower
1. Place a rope or steel cable (see notes) from the top of the mast to a
solid connecting point away from the tower. This is called a tram line.
If you use a tree, make sure it is healthy. Don't tie on branches, but onto
the trunk. In
over. You can also use a pickup truck bumper. (Make sure you untie the
rope before you leave.) I have also used steel posts (any farm store has
these) and cut them in half with a torch. Pound two in the ground, one behind
the other and attach the line to the first and backstay the front to the back
with appropriate rope or cable. Tensioning the tram line is important,
but
many people have diferent opinions. (See the notes.) Caveate Emptor (Or
something like that)
Note 1-A
What may have been missing from your description, Lee, was that the
tram line which supports the antenna on the way up should NOT be very tight.
few years back which analyzed the physics of this arrangement. Among other
things, he found that the lateral force at the top support (tower/mast)
GREATLY increases when the tramline gets taught and straight. It is MUCH
less stressful on the whole affair to let the tramline have a bunch of sag
in it.
If there is any question about the strength of the top support,
I'd recommend using a temporary back guy, from the top support to a solid
attachment on the ground, running 180 degrees around the tower from the
tramline bottom.
I can personally attest to these affects. I was using a schedule 80 water
pipe as a mast, and put a slight bend in it while raising a KT-34XA with too
tight a tramline and no backguy.
Tramlines are cool. It takes all day to set them up properly and another to
take them down. But when they work right, I've been able to install large
antennas with no more ground crew than the XYL.
Think through your arrangement carefully, visualizing each step in the
process. This will help you remember details like 'the lifting line goes
OVER the boom' etc...
-Tony, K1KP, fisher@hp-and2.an.hp.com
Note 1-B
Lee, Depending on the height of your mast above the tower you may not
Want to attach the rope to it, lest you bend or break it. If you think about
it,you put an enormous sideways force on the mast when trying to raise a
heavy beam with the supporting (tram-line) rope reasonably taut. One
option is to attach the tram-line to the top of the tower (always assuming
it can handle the sideways strain) and use a come-along and/or a gin-pole to
get the beam to the right height on the mast. Alternatively, you can use a
second rope in the opposite direction to the first (suitably secured of
course) to serve as a back-stay to relieve the sideways strain imposed on
the mast by the tram-line rope. In my experience, it is best if you can
attach the tram-line to a point a good bit higher than where you need to
attach the antenna. You can then operate without the tram-line rope being
too taut, and once you have raised the antenna almost all of the way up the
tram line, slacken it to allow the antenna to come in to the right place.
While pulling the antenna up the tram line with a tractor has much to
commend it, you need to have a person on the tower to watch that the pull
rope, where it is tied to the load, does not reach the pulley through which
it is being pulled! My tractor could not sense the increased strain when
this happened, and the rope broke allowing a 6-element 20-meter beam (60 ft
boom) to slide back down the tram-line and,on reaching the ground, turn
itself into a prettzle!
-John N3HBX.
Note 1-C
The tram line needs to be somewhat tighter as the beam approaches
the tower, other wise you'll get fouled up with the last set of guys. My
approach is to tighten the tram reasonably tight to start with so by the
time the beam gets halfway up the stretch makes it quite loose. That's if
I'm using 1/2 inch rope. On bigger stuff 5/16 ehs is used, stretch isn't an
issue then. Regardless, too much tension when the beam is in the middle
2/3rds certainly does cause a lot of side pull on the mast. A back guy is
always a good plan, a bent mast is a real hassle. We use those 4000 lb
rated cable pullers to tension the tram, and once the beam gets near the
tower we just tighten the tram, the beam is lifted away and you
can the tram the beam right to its' resting place. On bigger beams (like 3
el 40 fullsize 400 lbers) the tram is usually attached the tower, not the
mast. Once the beam is trammed up next to the tower, a chain fall type of
hoist is used to pull the antenna vertically up into place.
-Don VE6JY is Don Moman email: ve6jy@freenet.edmonton.ab.ca
Note 1-D
I think you've got the basics down pat. It's really a lot simpler
than it sounds. Just a few small points.
I recommend wire for the tram line instead of rope. 3/16" guy wire
works great for me. Also lets me use old guy grips for attaching to mast,
etc. Use a come-along to tighten tram line (of course, not TOO tight).
Make sure the tram line ground attachment point is beyond the radius of
the
guy wires.
-James / k1sd (ex KD1NG)
Note 1-E
An elegant alternative to a separate backguy is to use one
Continuous cable that passes through a pulley/sheave at the mast. That way, the forces
Are roughly equalized at the mast and you only have to deal with one cable.
Either method does work and is highly recommended for medium sized
Projects and up. Two other nifty facets are 1) you can raise the antenna part way
Up the tramline while dangling a temporary feedline to it for initial
testing.
And 2) the antenna can be lowered quickly for tuning adjustments or
installation problems and raised again in a matter of minutes. This would
include having a tag line hung up on the antenna, etc. You can lower it and
raise it back up again in 5-10 minutes. Like any similar job, it's the
rigging that takes most of the time.
Again, if anyone is interested in an illustrated article on
installing
yagis
including tram systems, an SASE to TOWER TECH,
Woodinville,
WA, 98072, will get you a free copy. BTW, Tom Schiller, N6BT and Force
12,
has written a book called "Array Of Light" and he has a chapter on
installingyagis. His methods are sell suited for limited space projects
where you may not have room for a tram line (sneaking the beam around guy
wires, etc.). It's $10.00 from Force 12 and an interesting read of Tom's
extensive tower and antenna knowledge.
-Steve K7LXC
Note 1-F
I think you've got it down just fine! I prefer to use a piece of
steel guy
wire (3/16-inch or 1/4-inch) or wire rope (only because I have oodles of
it, 1/4-inch) as a catenary in place of the supporting rope. This can be
tightened more than rope (but you may need a back-stay in the opposite
direction if you attach it to the mast on the tower) if you need the get the
yagis up higher (such as over a house, tree, etc.) Use a turnbuckle if you
want to get it real tight (but don't make it tighter than you would a guy
wire). Using this method I have single-handedly raised and lowered beams as
big as a 204BA (and recently I lowered a Cushcraft 5-el. 20m) without any
problems. If you must do it single-handedly (not preferred but sometimes
necessary!), here's my method to raise a beam:
Install the supporting catenary as you describe and raise the beam so it is
just a foot or two below the mounting point. Tie off your pullling rope at
the bottom of the tower. Then loosen the catenary at the ground end and walk
it toward the tower and leave it there. The beam will now be laying against
the tower or mast instead of hanging out away from it on the catenary. Climb
the tower and use a small block-and-tackle or come-a-long to pull the beam
into final position. Reverse the procedure if you're removing a beam.
-Jon AA1K
Note 1- G
Lee, your method as described says: "rope" and "string". That will not
work! It requires Steel-rope for the tram/pulley arrangement and "rope" (I
use 1/2 inch poly) to pull the antenna up the tram cable.
The steel tram cable needs to be significantly tensioned to support even a
medium size beam to a reasonable height. I tensioned my tram cable (3/16
stainless steel rope) to 1000 Lbs tension (as measured with a LOOS tension
gague) to haul up my 40-2CD to 67 ft. Tensioning to anything less sagged
too much to pull the antenna up!!
So, you see, that's why I say you can't (shouldn't) use a (non-steel) rope
for the tram in you description. And the forces on the pull line are also
significant. I use the 1/2 inch poly and pull it with a tractor!
All this is on tape, and, as I have offered, I will send you (and anyone
who requests it) a copy of my tapes, for the cost of the tape and
shipping/duplicating expenses.
I have already received many many requests for the tapes. I am in the
process of buying blank tapes, determining the shipping costs, and the
duplicating costs. I plan to incorporate all three videos on one tape for
all of you. Once I have this done, I'll send all who responded to my offer
an email with the cost.
If you haven't sent me an email requesting copies of the tape,
please do so. Once I tell you the cost, and I'll ship you a copy once I get your check.
-Bill, N3RR
Note 1-H
I used 1/4 EHS for the tram line to pull my 402CD up to 83 feet. I ran the
tram "way" out from the tower and ran it around a 6 inch wooden fence post.
I pulled like blazes on the "dead end" (the end coming back around the post)
and then performed some gymnastics while I clamped the dead end to the live
end with 2 cable clamps all the whilst attempting to maintain as much
tension on the cable as possible.
I ran 1/2" rope through a pulley at the bottom of the tower up to a pulley
muffler clamped to the 4130 2" mast and down to the antenna. I pulled it up
by hand, reclimbed the tower and bolted the antenna on the mast. I'm more
brawn than brains, but it worked quite nicely.
I did pull it up and down several times snagging the elements in the top
guys before I remembered a concept called "tag lines." I wrapped some
closeline rope loosely around the forward most element end (one end only)
and loosley taped it to the element. It worked perfectly allowing me to
steer the element out of the way of the guys. I held the antenna haul rope
with one hand and the tag with the other. Just as I got it in perfect
position and started to ponder how hard it was going to be to get the tag
line freed, the tag line fell off. Perfect!
I live out in the boonies and did this solo. It would be a lot easier with
some help, but I was surprised at how well it worked. I used a HY-GAIN boom
to mast clamp and other QHS (NL) mods have been done to my 402, but it still
only ways around 65-75 lbs.
-Matt-K7BG
Note 1-H
I've used both steel wire-rope and good regular rope for the tram line. I
tend to favor the regular rope for the following reasons: 1) Easier to work
with. 2) Non-metallic; SWR check can be done on the antenna while hanging
from the tram line.
A good 1/2" braided rope like Yale Double Esterlon has very little stretch,
and a tensile strength of 10,000 lbs. Highly recommended for all tower
work.
Yes, keeping the antenna above the top guy can be a problem. The method
I've settled on, in most cases, is to run the tram line directly above the
top guy in one direction, tension it, and then drop that top guy (letting it
hang straight down the tower). The tram line takes the place of the guy wire.
As soon as the beam reaches the tower, the guy wire is reattached, the tram
line is removed, and the beam is raised the rest of the way.
-Steve Maki K8LX
2. Install two pullies on the rope. The pullies will be used to harness
the beam to the tram line.
3. Move the antenna under the rope and secure it to the lower pully on the
rope. The boom should be perpendicular to the rope. Make sure that the
boom to mast clamp is facing the right direction. The antenna should be
tied to the balance point. You should use a harness that can "balance" the
antenna on the rope. By doing so, you will not need to use tag lines. Make
sure once the antenna is in place you can remove the harness ropes from the
boom.
4. Attach and 3 to 4 foot arm on the boom parallel to the rope using a
U-Bold. At the outer reach or the arm attach the second pully. You now are
supported by two pullies. The reason to put the arm on the boom to act as
a lever and keep the antenna from rolling over or flipping while raising the
antenna. It cannot flip over with this arraingment. (See the Option
below) I like Pete's method. Remember, I have not done this yet, but I
think it would work better of the "tiller" is away from the tower so you
don't have to take it off before you attach the beam to the mast.
Option 4-A
The arm should be down-wire from the boom, not up-wire, so it won't
get in the way when the antenna arrives at the mast. Not only does the "tiller"
keep it from flipping, it enables you to pre-position the antenna with
element tips high, so that when it arrives at the tower they won't get
fouled in the top guys. Preferable way is to use a two-point harness tied to
the boom at equal distances on either side of the balance point, as far
apart as you can reach to untie while at the top of the tower. That way,
the harness tends to keep the boom horizontal. If you secure the tram wire
at the right height (far enough) above the point on the mast where you want
the boom to wind up, you can use the play in the
2-point harness to push/pull the boom over against the mast.
-
5. OPTIONAL: Tag lines. A tag line can be place on each end of the boom
to keep the antenna horitontal during lifting. Tag lines are very long
loops of rope which can be taken off after the antenna is in place. Smaller
rope or cord could be used for the Tag Lines I think most people hate tag
lines. I have not riggedthis before, but I think making a harness which
balances the antenna correctly, along with the tiller concept would allow
for smooth raising of the antenna with a minimum of ground crew.
6. Place a pully at the top of the tower and place a pull line through the
pulling and attach it to the arm on the boom of the antenna. The pull line
rope then goes to the ground.
7. Slow pull the antenna up the rope until it comes to a place where you
want to attach it to the mast. A person on the ground might have to loosen
the tram line to allow the placement of the antenna on the mast. I suggest
that a "hay-knot" be used at the lower end of the tram line to insure that
the rope doesn't get out of hand.
Note 7-A
Another trick is to use a pulley/snatch block at the bottom of the tower
so that the haul rope goes horizontal for easier pulling as opposed to
pulling down. A down pull is all arm strength whereas with a snatch block
you can put the rope around your waist and just back up.
-Steve K7LXC
Option 7-A
I envision that one could have a gin pole set on the tower with the tram
line tied to the tower and not to the mast. If your mast and rotor could
take the sideways pull with a back-stay that would be fine. You would then
have a the tram attached above the point at which you were going to install
the antenna. All you would have to do is to swing the antenna over to the
mast and bolt it on.
But, one could attach the tram line to the top of the tower or below the
attachment point, pull the antenna to that point, attach the gin pole rope
to the antenna, loosen the tram harness and drop the tram, and then raise
the antenna in place on the mast. A little more complicated, a little more
rope, but would not place burden on the mast and rotor and would be less
rigging time.
-Lee K0WA
Addendum 1 (Not exactly what most people have - at least not the guys I
Run with)
Lee, Here is the antenna lifting arrangement we use at NK7U to lift monster
beams. This arrangement has been used to lift 20M6's (60ft booms), 20M5's,
40M4's, etc. 2 towers are needed to do this however.
1. A large pulleys is needed at the top and bottom of both towers.
2. One rope is run from the ground, through the bottom pulley, up through
the tower, to the top pulley and then back down to the ground at a point
between the 2 towers
3. The same is done with second rope on the other tower. The ropes will
then form a "M"
4. The top of our boom to mast plates have 2 holes drilled into the corners
to accept a yoke. The yoke is attached to the plate with 2 snap links.
The top side of the yoke is attached to the ends of the 2 ropes. A photo
of this setup can be found on our home page at:
http://netnow.micron.net/~jcullum/image/joe20.jpg
5. A tag line may be used to keep the antenna from rotating.
6. At this point you are ready to lift. Actually it is more of a pull since
you are pulling horizontally against the bottom of the tower. We use a
4-wheeler on the side that the antenna is going to. And the other rope
has 2 people on it. The antenna can be lifted straight into the air, past
the guys and then swung into the tower at the appropriate spot. Multiple
beams can be installed up and down the tower without ever having to move
the pulleys.
A benefit of this arrangement is that the antenna can be lifted quite a way
off the ground and swr measurements can be taken. Getting the antenna back
onto the ground is only a matter of releasing the ropes (carefully). You
can also pull the antenna up 50 ft or so and use a tag line on the
reflector to point the antenna straight up for more accurate (?) swr
measurements.
Other photos of the antenna installations can be found on our home page
at: http://netnow.micron.net/~jcullum/html/nk7u.htm
-Jim K7MK jcullum@micron.com
