APPENDIX: SURVEY FORM USED TO RECORD INFORMATION OBTAINED
DURING TELEPHONE INTERVIEWS
Each question is more fully described by the italicized notation following it
TOWER COLLAPSE SURVEY SHEET (Key)
TOWER IDENTIFICATION: Boldfaced items are most important
Tower name: Station call letters, e.g.,"WTSL-FM"
Date: Of interview
Owner or studio address/telephone:
1st- or 2nd-hand info?: To indicate accuracy of info, e.g.,
eyewitness to event? employed at station at time?
TOWER LOCATION/SITE DESCRIPTION:
Tower location: e.g., "3 mi south of I-89 on Rt 12A", or
"top of Big Mt", or "at intersection of Elm and Main St."
Location description: e.g., mountaintop, open fields, forested,
Base elevation (asl):
Top elevation (asl):
urban, high plains
Engineering post mortem done? Formal report available?
Date and time of failure:
Suspected cause of failure: e.g., "Light rime icing caused by low
Description of failure event: e.g., "Broken guy wire allowed
cloud ceiling followed by clearing skies and increasing wind.
the main antenna to snap off. Antenna snagged and slid down
Top NE guy attachment on the tower finally broke after 2 hr of
a lower guy, breaking the anchor attachment. Top 300 ft of
continuous cable galloping."
tower then fell to the SW, bottom 500 ft fell to N."
Witnessed; or how long after did someone arrive on site?
How long after collapse did an engineer arrive on site?
To indicate what confidence we can have in the estimation of the
To indicate what degree of confidence we can have in the
ice and wind at the time.
estimation of the failure mechanism.
Estimated ice thickness and type: e.g., "max. 1-in. radial
Max distance that tower debris landed from base?
Estimated windspeed: At or about time of failure
rime on upper 300 ft of guys", or "6 in hard rime at top N
Icing source? In-cloud or precipitational
side entire tower dminshing to 1 in at 600-ft level"
Age: Year erected
Face width: Of tower, or various widths and
elevations of taper points
Guy levels: # of elevation points where guys
Anchor pattern: Ground pattern of
Ice protection: Heaters, radomes, wide-band
attach to tower
Design load specs: For wind and ice
HAAT (ft): Height above avg terrain*
Tower height (ft):
* HAAT, a radio and tv broadcasting term, is a measure of an antenna's effective height above the surrounding terrain
100% off air time: How many weeks, months
% coverage w/ emerg equip: % of
Normal ops returned when? How many weeks
normal broadcast area
Describe equipment/adjacent property
losses and est costs: Est of total costs if
e.g., losses to tower & equipment,
breakdown not available
fencing, buildings, vehicles, advertising
revenue, labor, etc.
1. e.g., tower manufacturer's rep
2. local newspapers
Location, date and call letters of other collapses: Any communication tower, incl AM, FM, TV, microwave, cellular, two-way; either in the
same vicinity or elsewhere, same or separate storm.