An interesting exchange, though it taught me more about people than the problem.
Has anyone actually experienced failure of a poly tunnel under the weight of snow?
If so what was the mode of failure?
This year's weather was exceptional (I hope!) but I am wondering whether it is truly essential to remove snow?
Snow is a good insulator and the tunnel could possibly act as 'centring' or formwork that would allow the gradually compacting snow to form an arch that would absorb most of its own weight and even stand up if the polythene ruptured?
Do people use poly tunnels in countries where snow is inevitable?