A lock plate for a locking device of a jet pump beam, the locking device including a locking sleeve including a lower portion, may include a beam bolt opening sized to receive the locking sleeve, and a spring arm including plurality of spring a ratchet teeth sized to mesh with locking sleeve ratchet teeth included in the lower portion of the locking sleeve, the spring arm being structured such that the spring arm has both i) an engaged position where the locking sleeve is in the beam bolt opening and at least a portion of the capture feature overlaps vertically with an upper surface of the lower portion of the locking sleeve, and ii) a disengaged position where the locking sleeve is in the beam bolt opening and the capture feature does not overlap vertically with the upper surface.