How DO The Raise Big Antennas?

I’m thinking about the fairly narrow ones that rise 100’s of feet. How do the get them up? (No jokes about drugs, please.) I can’t imagine they assemble them sideways and then ‘push’ them up.

If I had to do it I’d have some sort of elevator device that raises along whatever’s been assenmbled so far, lifts the next section up, bolts it in place, then climbs the new section, then repeats. With stops to add guy wires of course (Why ‘guy’ wires and not “guide”. for that matter?")

But that’s all an amateur guess. Google doesn’t seem to be helping.

Anyone know?

You may be right.
http://www.youtube.com/watch?v=2KvjwdXA89w&feature=related
I don’t know why there is no sound in this video.

a jin pole method can be used to erect the tower. it is clamped to the structure and gives a hoisting point higher than the tower sections. it is moved up as the tower is erected.

to get some parts at the top like the antenna itself a helicopter would be used.

That’s exactly what I was thinking of.

What are things coming to when you can get a better answer on YouTube (OK, with SD help) than on Google? And yeah I know Google owns YouTube.

According to the OED (not that one, this one) we have

If you go back far enough it’s cognate with ‘vision’.

I’ve participated in the raising of a tower and we used a jin pole. Worked very well, only issues were sometimes the legs of the tower sections didn’t align perfectly and took some muscle and persuasion to get joined.

I have a 70’ radio tower and it has a hinged base. It was tilted upright with my tractor and a good rope. Not doable on anything much taller though, at least by non professionals.

Used a gin pole as mentioned on self supporting towers up to 90’. Have not worked on any taller myself. One of my friends has two 120’ guyed towers. The first 60’ were tilted up similar to mine and the rest of the sections were added with a gin pole. The antennas were also added by gin pole.

On taller units cranes and helicopters are commonly used.

Back in the day when we needed tall antennae for off-shore positioning systems, our erection method was similar. The antenna tower sections were assembled lying horizontally (40’ to 100’ as required) on a 90-degree tilting base. Earth anchors (screw-type) were set at cardinal points and carefully measured guys attached to the tower from 3 directions with the fourth (lifting direction) running free. The (shorter) gin pole would be erected vertically on the tilting base with its top being guyed to the top of the longer antenna tower as well to the fourth anchor through a set of blocks for the actual lifting. With a 3 or 4 part block (number of pulleys in each block) the mechanical advantage was such that a couple of people could provide the lifting force. The top of the gin pole would be pulled down from the vertical and the antenna would lift from the horizontal in response. As the gin pole approached the horizontal the blocks would eventually “two-block”, but by then the tower would be nearly vertical, the three measured guy sets would be controlling movement and the lifting direction guy would be reefed up and…voila! A bit of guy adjustment to get the antenna vertical in two planes and Bob’s your Uncle -you’re in business. Taking them down was essentially the reverse procedure.

In the You Tube video the top most section has vanes spiraling up the outside of the section. I’ve seen these on shorter stacks as well. What is the function?

The last section you see is the actual broadcast antenna and feed line being installed. I do not know what the spiral vanes are for.

We typically use a crane to stack the bottom 60-100 feet or so of self supporting towers, then use a gin pole as others have mentioned to erect the rest of the tower. Antennas are typically hoisted using a tower top block and a ground based winch to raise them to the required height.