Ok, I've actually done this 
We did a film shoot where we had to lift a man off the floor. We had balloons that were about 2m across when inflated and each could lift about 1kg. We needed 75 of them.
Realistically, we were tying them in bunches of 5 to the empty helium bottles. There was a slight breeze on that day and I'm not joking when I say one bunch would drag you across the field if the breeze caught it. Once we had a few bunches tied up it was just unmanageable - it's very very difficult to handle something that's pulling UP! We had them all inflated, but I think we got to about 25 or 35 tied to the harness and decided it was too dangerous to continue because someone was going to get blown away and we had no way of getting them back down. We used a weighted dummy in the end
The other amazing thing was the speed they flew off when they broke free. You've seen a normal balloon fly off; the massive ones literally shot into the sky and within a few seconds were through the cloud cover and out of sight. Since we were working close to Heathrow on a flight path we decided to call air traffic control because we had lost quite a few and the ones going up in bunches of 5 were actually pretty damn big!
Oh, and **** me, when they popped it sounded like a bomb going off. Everybody on set jumped no matter where they were
We did a film shoot where we had to lift a man off the floor. We had balloons that were about 2m across when inflated and each could lift about 1kg. We needed 75 of them.
Realistically, we were tying them in bunches of 5 to the empty helium bottles. There was a slight breeze on that day and I'm not joking when I say one bunch would drag you across the field if the breeze caught it. Once we had a few bunches tied up it was just unmanageable - it's very very difficult to handle something that's pulling UP! We had them all inflated, but I think we got to about 25 or 35 tied to the harness and decided it was too dangerous to continue because someone was going to get blown away and we had no way of getting them back down. We used a weighted dummy in the end
The other amazing thing was the speed they flew off when they broke free. You've seen a normal balloon fly off; the massive ones literally shot into the sky and within a few seconds were through the cloud cover and out of sight. Since we were working close to Heathrow on a flight path
we decided to call air traffic control because we had lost quite a few and the ones going up in bunches of 5 were actually pretty damn big!Oh, and **** me, when they popped it sounded like a bomb going off. Everybody on set jumped no matter where they were
