[squeezy]

Most discussions about clamps here are about over ground where as I can remember my Dad having a hole in the garden and he burried loads of parsnips.  does anyone else do that?  Here in France many locals remove the inner washing machine tub and bury that first as it keeps the vegetables cleaner and very fresh.
 

[arugula]

Haven't done it, but I've certainly heard of underground storage, rather like the method employed on this page.

Oh, and welcome! 

[Trillium]

The winner washing tub would be a great idea as any burrowing pests won't get a free feast. But don't wash the carrots or veg before storing as it tends to shorten storage life.

A thick plank of wood right over the tub, then other items stacked on top to help prevent freezing would be a good idea. The plank would allow easier access.