The About section of the site states:
iPhones & iPads are not supported by the story viewer.
A couple of users have suggested using the Puffin browser to access the site but as I personally don't own an iPad, or ever plan to, I can't comment further. BTW, this isn't the only site which iPads fail to display correctly, there are many. This site is designed to work with standards compliant web browsers that support a full javascript implementation, something the iPad, despite however many have been sold, doesn't appear to offer.