Wednesday, May 1, 2013

An airborne wrecking ball???


I was amazed to find this video clip of an AS332 Super Puma helicopter of Airlift AS in Norway.  It's using a specially-built multi-ton underslung wrecking ball, suspended from a very long line, to knock down unstable rock formations on a cliff overhanging Highway 70, a Norwegian coastal road.  According to the subtitles, multiple rockfalls had blocked the road over a period of a year or more, so it was decided to remove as much of the unstable rock as possible to prevent further rockfalls.

I recommend watching the video in full-screen mode.





That's pretty remarkable flying.  If you watch helicopters with underslung cargoes, they typically try to avoid oscillations or uncontrolled swings at all costs, as these can render the aircraft unstable - even unflyable in a worst-case scenario.  This crew had to do the opposite - deliberately encourage oscillations by swinging the wrecking ball, but not so much that they tugged the helicopter out of control.  It must have taken a fair bit of trial and error, and a lot of skill, to get it right.

Peter

7 comments:

Douglas2 said...

Seems to me artillery might have been safer.

Mad Jack said...

Doug:

I was thinking the same thing. Maybe a .50 cal machinegun or something.

dave said...

One hopes for explosive bolts on the cable as well, just in case.

perlhaqr said...

I just don't see how they could hope to get enough of the cliff face with that little (comparatively) wrecking ball and the water bucket they were using.

Now, what they ought to do is rent out, say, the Iowa, and load up some 16" buckshot shells, and then stand back about 20 miles so there's actually some pattern spread, and pelt the cliffs with that.

And then get some of those great big firefighting ships to park near the base of the cliff and hose it down.

:D

BobF said...

I was thinking chain in an artillery piece.

perlhaqr said...

BobF: I like the idea of 16" chainshot as well... :D

Scott said...

"It must have taken a fair bit of trial and error, and a lot of skill, to get it right."

And a whole lot of OT by guardian angels!