Archived report · 2 min read · Set in Stanhope Road ·
Radio Mast Guy Wires on Stanhope Road
A tension survey of the guy wires on the Stanhope Road relay mast finds them humming a hymn tune in unison, and the tune changes key whenever the wind changes direction.
- filed: Filed with the broadcast maintenance schedule
- reference: RM/SR/31
Subject: guy-wire tension survey, Stanhope Road relay mast, height 84 metres.
1. The mast was erected in 1958 and is supported by twelve guy wires at three levels, anchored to concrete blocks in the surrounding field. Each wire is a galvanised steel rope of 12 millimetres diameter. The wires were last inspected in 2021.
2. Tension readings were taken at each anchor using a calibrated gauge. All readings fall within the design range. No corrosion or fatigue was found on any wire.
3. The wires emit a low continuous hum in wind speeds above eight knots. The hum is audible from the road and from the nearby farmhouses. Residents have reported it for several decades.
4. A recording was made at the base of the mast using a contact microphone attached to the lowest wire. The signal was analysed for frequency content. The dominant pitches correspond to a sequence of notes that matches, within a semitone, the opening phrase of a hymn in common use in the district.
5. The sequence was checked against the regional hymnal. It matches the setting for the third verse, which is not usually sung in the parish church because the setting is known to be difficult.
6. The pitch of the sequence shifts when the wind direction changes. A shift from south-west to north-east drops the phrase by a tone. A shift back raises it. The surveyors were unable to reproduce the shift with any mechanical cause.
7. Recommendation: no change to the mast. The residents have requested that the wires be left as they are.
8. Observation not explained by the survey: the surveyor who recorded the sequence began to hum it on the walk back to the van. He was not aware of doing so until his colleague asked him to stop, because the wires had begun humming it back.