The Tenderizer is a Melee Weapon in Fallout 3. It's a unique type of Sledgehammer and deals more damage. It can be found in the storage room at the Anchorage Memorial, however the storage room door is missing a component. To gain access to the Tenderizer you'll need a Lockpick skill of 50 to pick a safe that contains the needed door component and you'll need a Repair skill of 35 to fix the door. If your Repair skill is 95 you can just open the door there.