 Near the RSJ which spans the moat are seen five massive cracks and more repair work, again from the siege trials of 1907, but this time, the hole in the base of the ditch was not dug by the defenders but was the result of a failed "camoflet" or "petard".Accounts vary as to the title of the device used, but it was a type of tunnel driven from the attacker's side along the length of the moat to here and exploded.The first left the now mostly back-filled crater but at the second attempt blew a section of the wall outwards causing the damage still to be seen.