Hekaton Siege Claw

Weapons and attacks with this special rule
                                                may re-roll failed Armour Penetration rolls against
                                                fortifications and immobile structures (such as
                                                bunkers and barricades), and add +1 to any result
                                                rolled on the Building Damage chart. If this attack
                                                damages a bulkhead or wall section of terrain and
                                                destroys it, remove that section of terrain from
                                                play if possible.