The broadfork. I had heard about them but had never seen one in real life. They are used for loosening the soil waaay down deep which is exactly what's needed for carrots and some other root vegetables. It's also a low-tech grid-down muscle-ready substitute for a tiller.
Turns out to be a piece of cake. Even though Tom is pictured here demonstrating it, I was the one who did a 14 x 6 foot section myself with hardly any effort. It couldn't have taken me more than 15 minutes. The toughest part was carrying it back and forth from the garden shed. It did a great job!
Tom plans to use it to loosen the soil for harvesting potatoes also. It worked great in preliminary testing. I love this thing and am grateful for it.