THRESHOLD LOG 10-G7

Designation: Maintenance Shaft X-12

Apparent timestamp: 22:17 / 03:44 / 22:17

Entry method: Vertical ladder through upper access plate

Environmental Baseline

Intermittent LED strips, 4000K, average intensity 45 lux with 3.2-second blackout intervals.

Ambient temperature 12.4°C. Humidity 58%.

Air pressure matches external baseline. Instruments register continuous mild negative pressure.

Background sound consists of metallic ticking at 1.1 Hz. Source remains unlocated. Air movement is absent.

Spatial Observations

Shaft diameter measures 1.8 m. Estimated depth from upper plate to lower platform: 40 m. Measured depth on descent: 27 m. Measured depth on subsequent ascent: 53 m.

Walls: painted steel with circumferential weld seams every 1.5 m. Paint flaking occurs in identical patterns at each seam.

Ladder rungs spaced at 0.3 m intervals. Counted rungs total 89. Calculated coverage for 27 m requires 90.

Lower platform is circular, 1.9 m diameter. Floor surface is non-reflective metal. No drains or openings visible.

Access plate above remains open. View through plate shows the originating corridor. Corridor lights appear stationary while shaft lighting cycles.

Anomalies

Descent distance increases by 4.2 m with each full traversal cycle. Ascent distance increases by the same amount.

Light emitted from upper LED strips fails to illuminate surfaces below 12 m. Surfaces remain visible by independent means.

Metallic ticking rate remains constant. Echo of the tick returns 0.4 seconds before the tick is heard.

Laser rangefinder aimed downward returns alternating values of 27 m and 53 m on successive pulses. Physical tape measure extends without resistance beyond expected length.

Elapsed time on recording device is 41 minutes. External chronometer shows 17 minutes elapsed.

Lower platform temperature is 4.7°C lower than shaft midpoint. Gradient does not reverse with direction of travel.

Entity Notes

None recorded.

Exit / Continuity Status

Exit achieved through original upper access plate after 44 minutes subjective.

Ladder rung count on final ascent totaled 112.

Residual effect: vertical depth perception remains mismatched by approximately 2 m for 19 minutes after exit.

Recording device clock runs 1.4× faster than external reference for the duration of residual effect.