
The nacelle catwalk in an NX class starship

A schematic showing the location of the catwalk (highlighted)
Thecatwalk was the unofficial designation for the lateralaccess conduit running the entire length of thewarp nacelles of anNX-classstarship. Located at the center of thenacelle, just below the ship'swarp coils, the catwalk was accessible through a single verticalJefferies tube.
Protected by an outer shell composed of anosmiumalloy, the catwalk was used as amaintenance shaft, though it was only operative if the ship'swarp drive was shut down. With warp systems online, the catwalk was subject to extreme hightemperatures and was not suitable for habitation. The catwalk was divided into several compartments. (ENT: "The Catwalk")
In2152, thecrew of the starshipEnterprise NX-01 took refuge from a deadlyneutronic storm within the catwalk. Utilizing a makeshiftcommand area which the ship'sChief EngineerCommanderCharles Tucker III prepared,CaptainJonathan Archer,First OfficerT'Pol andHelmsmanTravis Mayweather were able to controlEnterprise'snavigation through the storm. (ENT: "The Catwalk")
Later in 2152, Archer once again led his crew into the catwalk whenEnterprise was invaded bynon-corporealbeings. Unable to penetrate the catwalk's protectivedeflector shielding, the beings were kept at bay long enough for Archer and his crew to repel their attack. (ENT: "The Crossing")
InJanuary2153, Mayweather told hismother,Rianna, about how the crew had, a fewmonths beforehand, needed to "squeeze into one of the nacelles for a coupledays" due to a storm. (ENT: "Horizon")
TheUSSEnterprise-D also possessed a catwalk. In2368, whenLieutenant CommanderGeordi La Forge experienceddizziness due to a phase shift in his visual receptors caused by the ship being in atemporal causality loop, he stated that at first he thought the catwalk was spinning. (TNG: "Cause And Effect")
