The upper level of the equipment room consists of a steel-framed platform covered with a rolled-steel deck plate. Cast into the east outer wall is a narrow, steel-faced bench, calibrated with compass bearings. Part of a complex optical alignment system, the bench originally supported an "autocollimator" (no longer in place) that was used to align the missile's guidance system.
Directly above the bench is a canted cylindrical porthole (sight tube) glazed with bulletproof glass that is now permanently welded shut. This sight tube is aligned so as to point through the open access hatch, which allowed guidance technicians to establish visual references to a pair of azimuth markers (surveyors' benchmarks) located on the surface outside of the security fence.