How to knock down a 1000 foot TV mast in seconds!

[tony sayer]

[Andrew]

Is there lots of peat and boggy moss up there that might have cushioned the antennae bits ?

[Martin Brown]

The magic smoke came out a couple of months ago. TV for some areas here is still not restored. They have bodged transmitters for the cities.

I'd have watched it fall down if I had known. It was a clear landmark for miles around until it suddenly vanished!

Didn't really affect me as I'm on Freesat.

Elmley moor is within range for most modern TDTV tuners from here but it requires someone to go up and tweak the customers aerial and/or put a longer one in. TV antenna folk have never been so busy.

Local TV shops have a "do not adjust your set" sign in the window!

[Martin Brown]

Although there is after falling 1000' the mangled remains have scrap metal value only. UHF broadcast kit is quite tetchy about dimensions.

[Andy Burns]

Although there was a claim they were "using controlled detonations in order to preserve sections for the continuing forensic investigation into the cause of the fire"

I wonder whether that worked-out?

[Tricky Dicky]

Well they changed their mind quick, on the local news they were talking about repairing it only a few days ago. There was a lot of complaints that the temporary mast was not going up quick enough.

Richard

[Brian Gaff (Sofa]

Maybe they had seen some worrying signs during the recent windy weather, you would not want it to fall over with no warning would you? I still feel though that had they got their finger out they could have stabilised it for a lot less than a new one will cost even if much of the transmission line would have needed changing. They must have had a method of doing that in the first place since they tweaked the aerials every time they needed to change the channels and the polar response.

Brian

[Brian Gaff (Sofa]

Have they not got those clips around the wrong way, Also since when was knocking something down become dismantling? I in that case dismantled a shed a couple of years ago, with a sledgehammer and some cutting tools, the latter not operated by myself, for obvious reasons!

Brian

[Martin Brown]

It had fire running right up the inside and a chimney effect from a

1000' mast boosting the flames at the base. The miracle is that it didn't fall down sooner. We had some pretty serious winds last weekend.

The black magic smoke was seen escaping from the very top.

The structure was utterly beyond repair. They were just waiting for a nice calm day to drop it. The new one will be much less impressive. (and only cover about 95% of the previous one)

Much safer now to work near it once it is flat on the ground.

Saving grace is modern TV tuners can get more remote transmitters.

[Harry Bloomfield, Esq.]

I was there, the week before it caught fire - no it wasn't me set fire to it.

[NY]

Yes, I think of "dismantling" as a fairly ordered process, unbolting things, putting them aside carefully with a view, perhaps, to re-assembling. "Demolishing" is a much less ordered process involving a wrecking ball or explosives or the Fred Dibnah "cut a hole, support it with pit-props, burn those props away and watch it fall" process.

As you say, the interview clip was filmed before the dramatic opening shots of the demolition. The mast fell fairly cleanly: after the bottom section broke low down and kinked sideways, the top 2/3 fell vertically without toppling until the top bit eventually hit the ground when it alone toppled sideways. From some drone footage, the top bit fell across an access road, though it looks as if this runs along the length of the hill rather than the more well-used track that provides access from low down onto the hill.

[PeterC]

The mast must be fairly light - part fell across a buildng and in the closer shot of that the building was still intact.

[Andy Burns]

Did I read 500 tonnes?

Seems on the high side given it was 300-odd metres

[PeterC]

The mast must be fairly light - part fell across a buildng and in the closer shot of that the building was still intact.

[Mark Carver]

If you add in the aerials, SHF dishes, feeders, the internal lift etc ?

[Mark Carver]

It'll have a fortified roof, to protect against falling ice, and other detritus hitting at terminal velocity

[The Natural Philosopher]

Like all towers, the bottom sections have to be butch enough to stand the weight of the top part...

[NY]

Ah, I didn't notice that part of it was across a building. I thought the top section of the mast (which remained vertical until it hit the ground and toppled over) fell over an access track rather than a building.

But now I look at the drone footage in Arqiva's video, I agree that the

*lower* section of the mast does look as if it falls right through the middle of the complex of buildings. I wonder if it didn't fall quite as they intended...

Comparing the height of that last "stub" with the height of the temporary mast in the bottom left of the picture, they are about the same size ;-)

But falling ice will probably be a lot lighter that a substantial section of the mast.

[Mark Carver]

Umm, I don't fancy being hit by a metre square, inch think slab of ice, particularly corner first, and while we're on the subject  any idea what, say,  300mm depth and 100 m^2 of 'wet UK' snow on a flat roof weighs ?

[NY]

gives values of between 50 (newly-fallen) and 800 (wet, firmly packed) kg/m^3.

100 m^2 x 0.3 m is 30 m^3 so between 1.5 and 24 tonnes. Yikes!

If a steel tube with a total weight of 500 tonnes falls so a section lands on the roof, I wonder what proportion of that total weight would be taken by the roof, assuming all the sections remain connected to each other and that maybe up to 5 m either side is unsupported by the ground. It will be more of a point load than snow which will be distributed over the whole area.