Congratulations Nelson & Ruby: she looks such a proud Mum!
Sally, we use farrowing rails like Karen described plus a cut-down metal sheep hurdle with a heat lamp hung behind it at the back of the ark. They don't really need a lamp to survive, but it means that when they're finished feeding they go and sleep in the creep area so are less likely to get sat on. We use a red bulb as the sows seem calmer with that.
Best of luck and keep us posted!