This version of the Enterprise was mainly built for combat operations, and did not have the scientific instruments nor amenities found on the ship's counterpart from the primary universe. In a briefing, Worf compared the ISS Enterprise-D to early Klingon vessels that focused on weaponry rather than research. The armaments of this version of the Enterprise included weapons capable of widespread destruction with a heavy reliance on nuclear weaponry, possibly due to the quantity of fuel needed for the elephantine engines making it more problematic to rely on anti-matter based weapons like photon torpedoes on a routine basis. The ship did possess holodecks, but in the mirror Starfleet, they were often used to assess the loyalty of members of the crew—Security Chief Deanna Troi had designed a n