At a certain height the load stops being the problem.
The problem becomes the machine that has to lift it.
A crane tall enough to reach the top of a slender concrete shaft has to be built up that shaft first, and then it has to come back down again.
Both halves take months, and the second half is the one nobody budgets properly.
So somebody asked what would happen if the lifting machine simply brought itself.
The answer changed the schedule by a season.
The pilot sits facing the wrong way on purpose
A helicopter needs no structure under it, which solves the first problem outright.
What it does not solve is precision. A section hanging on a line a hundred feet below the aircraft has to be lowered onto a stub of mast and turned until its bolt holes line up, and the pilot in the forward seat sees none of that.
So a heavy lift machine of this type carries a third station, at the back of the cabin, facing aft.
It has its own cyclic, collective and pedals, and a pilot sitting in it looks straight down the hoist line at the load.
For the placement itself that is the person flying the aircraft. Not watching it. Flying it backwards, with the machine responding to what the load is doing rather than what the nose is doing.
Which is why the fine positioning takes seconds instead of the careful minutes a ground crew and a crane operator would need to talk each other through it.
The tower and the piece going on top of it
The shaft below is poured concrete, formed continuously as the work climbed.
A mold sat on a ring of hydraulic jacks, concrete went in at the top of it, and as the pour set the form was tightened, narrowed and raised again, which is where the tapered profile comes from.
Above the observation levels the structure changes character entirely.
The broadcast antenna is a steel mast, and it arrived not as one object but as a stack of sections, each set on the one beneath it and bolted through matching flanges.
Finished, the whole thing reaches 1,815 feet.
The reason it exists is unglamorous: downtown towers had begun bouncing radio and television signals away from the people meant to receive them.
Three and a half weeks in March
Work on the tower began on February 6 of 1973 and ran about 40 months, with 1,537 people on it and a bill above 63 million dollars.
The helicopter arrived in March of 1975, and its first job was not the antenna at all. It took the crane off the top, because the crane was in the way of everything that followed.
Then it flew the mast up in sections, one at a time, in weather windows that opened at dawn.
The last piece went on on April 2 of 1975, three and a half weeks after the first.
The original method, a crane working from the structure, had been allowed six months for the same work.
That afternoon the tower took the title of tallest free standing structure in the world from a broadcast tower in Moscow, and held it for decades. It opened to the public on June 26 of 1976.
Numbers this story keeps getting wrong
The section count is the first one. Different accounts give 36, 39 and 44, and the tower’s own material says 39, which is the figure to use unless somebody produces the erection drawings.
The length of the record is the second. Whether it ran 32 years or 34 depends on whether you date the loss to the year a taller structure passed it while still under construction or the year that structure opened, and both dates get quoted as though settled.
Fuel burn figures circulate too, usually around 500 gallons an hour, without a source attached to them.
The pilot who flew the placements is not named in any account, which is a strange gap for a job that came down entirely to one person’s hands, the same way the people who move an 820 foot tanker or work a structure at sea mostly go unrecorded.
The tool decided the shape of the thing
What is easy to miss is that the antenna was designed around the helicopter rather than the other way round.
Section length and section weight were set by what the aircraft could carry to that altitude with fuel aboard and a margin for wind.
Had the crane plan survived, the mast would have been divided differently, because a crane has a different lifting curve and no ceiling problem.
The method is still standard for putting a mast on a finished tower, as the tower’s history records.
What has not changed is the limit. A helicopter lifts what it lifts, and everything above it has to be cut to that number, as construction coverage of the build describes.
The antenna sections were never really a lifting problem.
They were a packaging one.
