THRESHOLD COMPLEX EXPLORATION LOG
Designation / Log ID: 32-C29
Apparent Date/Time: 04 September 2026 / 09:12 (local) — secondary stamp reads 14:47 09 March 1977
Entry Method: Single steel door marked “C-14 CONDENSATE RETURN – AUTHORIZED ACCESS ONLY”. Exterior width measures 0.94 m. Interior width measures 1.08 m on entry and 0.91 m on exit.
Environmental Baseline
Lighting: fluorescent tubes, color temperature measured at 4100 K. Intensity constant at 87 lux.
Ambient temperature: 19.7 °C. Humidity: 68 %.
Background sound: continuous pipe resonance at 47 Hz. Baseline reading 29 dB.
Air movement: intermittent. Barometric pressure 1009.4 hPa on entry; 1015.2 hPa after 7 m of travel.
Spatial Observations
Gallery estimated 18 m long by 4.6 m wide by 3.8 m high. Laser measurement returns 13.9 m long by 5.9 m wide by 2.9 m high.
Floor: sealed concrete with yellow flow direction arrows. Arrow length measures 0.48 m. Pattern remains fixed after four traversals.
Walls: painted concrete over insulated pipe runs. Paint thickness measures 0.3 mm. Surface remains uniform under repeated contact.
Ceiling: exposed structural steel with three recessed light fixtures. Fixture count remains three after five visual inventories.
Repeating motif: every 2.7 m a condensate collection basin is recessed into the floor. Basin diameter measures 0.62 m. Water surface level is identical across all basins.
Anomalies
Visual inventory of return valves returns 5. Physical inventory returns 5. Measured return flow equals 0 L/min while calculated system demand across the same valves equals 12.4 L/min.
Floor remains level under spirit level. Measured water film on the lower wall panels slopes 1.8° toward the south wall. Slope reverses after 5 minutes of continuous observation without change in physical orientation.
Gallery pressure measures 1009 hPa while the external door indicator reads 1013 hPa. Seal integrity lights remain green.
Sound of droplet impact arrives 1.9 seconds after the corresponding surface disturbance is detected. Delay increases by 0.27 s for every additional 1.5 m of distance from the entry door.
Humidity at mid-gallery remains 68 % while frost forms on the pipe exteriors after 6 minutes of observation. Frost melts without measurable change in local humidity.
Local magnetic field strength measures 0.6 gauss at floor level and 2.1 gauss at 1.4 m height. Field direction reverses after 11 minutes without change in gallery state.
Condensate level in the basins decreases by 0.4 cm over 9 minutes while measured flow at all valves remains 0 L/min.
Entity Notes
None observed.
At the 6.8 m mark a localized temperature rise of 3.7 °C occurs across a 1.3 m radius. Rise persists for 11 seconds then collapses. No visible source or airflow change accompanies the event.
Exit / Continuity Status
Exit achieved by retracing path through the steel door. Exterior release required two attempts. Door handle temperature measured 4.2 °C lower than ambient on the second attempt. Residual sensation of wet concrete underfoot persisted for 3 minutes after exit. No further residual effects recorded.