More about the Broadfork / U-Bar
I was going to post this as a comment on the previous post, but it got long enough that I figured I'd make it a separate post.
I bought a U-bar digger like this one available from Lee Valley:
After acquiring it, I read an interesting bit about this type of tool in Elliot Coleman's The New Organic Grower. He advocates one like this, available from Johnny's Seeds:
His argument is that although the wooden handles may very occasionally need to be replaced, they cut down on the weight. He'd rather use a tool that is lighter all the time and once in a great while needs new handles, rather than a tool that is heavy every single time.
He also advocates the curved tines rather than the straight tines, based on the fact that the straight tines will act more like a pry bar, whereas the curved ones will have more of a rolling action through the soil.
I've only ever used the one I have, but I kind of wish I'd read Coleman's thoughts on this before I bought mine, since his comments do seem to make sense. Unfortunately, I've never seen either version in a store or somebody else's garden, so it's hard to look them over in person, much less try them out. But I thought I'd at least share what I've learned.
The other thing I wanted to mention was that in clay soil that has not been worked much, mine acts a bit more like a shovel than a fork, prying up one solid chunk of clay instead of breaking through it. Once the clay is broken up a bit, it's much easier. But even in heavy clay, I can see some benefit to being able to turn over a 30-inch chunk of turf at a time, if you don't mind a workout.
If anybody else has experience with this type of tool, I'd love to hear about it.