Volunteers with the SWCRS completed a number of site improvements as the Lemmon 650 site. The site suffered a tower failure during 2023’s winter storms, which brought record ice and wind to Mt. Lemmon’s radio ridge, bringing down a number of towers on the ridge. As a result, a number of maintenance activities were required to bring the facility back into compliance with the USFS Coronado Ranger District’s management plans.
Work consisted of a number of activities, below is a timeline of the events:
February 22, 2023 : Initial Tower Collapse
Heavy winter weather caused guy anchorage to fail on the tower; ice accumulation of over 12″ was observed from the webcams across radio ridge. At the same time, the observatory at the top of the mountain reported wind speeds of 30-40mph and temperature in the 20’s, an ideal and notorious recipe for ice accumulation: winds fast and warm enough for precipitation to efficiently wetten tower structures, cold enough for that to freeze quickly, and not windy enough to blow off adhered ice. Throughout the night, precipitation turned to snow as temperatures dropped, and the wind speeds increased with gusts reported up to 120mph, which is now collecting snow and wind load on heavily iced tower structures. A total of three towers collapsed across radio ridge, and the tower on which the Lemmon 650 resides had toppled, apparent the follow morning after sunset from the site’s web cam.
March 04, 2023 : Initial Restoration of (most) Site Services
Volunteer: David WQVS960 / K6DSA
David, WQVS960 worked to access the site, and installed numerous temporary antennas off-tower to bring most systems and services provided by the site back online. Heavy snow pack existed on site; work with what you got was the theme of the day. Using homebrewed snow shoes made from plywood and a boogie board as a material sled, David was able to access the site, and dig down the snow to gain entry. Snow drifts in excess of 6 feet in depth had piled up against the door.
The tower was not yet recoverable at this time, as it had been largely buried in snow. It became apparent that the failure mode of the tower was an anchor failure, since several guy wire’s anchor ends were laying on top of the snow but still connected to the tower. Reports that some reception of the Mt. Lemmon GMRS and Amateur DMR repeaters were reported; a remarkable feat since the GMRS antenna was buried under about 3 feet of snow, and the DMR antenna had its connectors completely pulled apart (meaning reception came from about 1″ exposed copper conductor.
Temporary antennas were set up on top of the equipment building, and most of the site’s services restored, although in limited capacity.
March 19, 2023 : Tower Recovery & Removal
Volunteers:
- Henry WQII718 / N7HND
- David WQVS960 / K6DSA
- Darren WRCU527 / K7VLL
- Bill WQXE928 / KG7HHG
- Lee WRUX974 / KK7ISV
- John WRJA611
- Jack WRHZ520 / KB7ZZY
With most of the snow pack melted off; the tower was dug up from site, cut apart where necessary, disassembled, and hauled off the mountain. The anchorage & concrete foundations for the towers appeared to be intact, it looks like several cable clamps that were holding the tower upright had slipped under the load experienced during the winter storm. Additional temporary antennas were installed on the building to bring a couple last systems back online into a limited operating capacity. The site still looked pretty rough, but at least it was functional at this point.
August 12, 2023 : Compliance Mitigation Day 1
Volunteers:
- David WQVS960 / K6DSA
- Darren WRCU527 / K7VLL
- Cory WRXR306 / K7RRR
- Larry WRPN676
- Steve WRMK211 / KI7SQP
- David WRJF717 / KJ7WWC
The Coronado Ranger District with the USFS maintains management plans and sets requirements for facilities hosted within forest lands. With the site still looking pretty rough from the winter prior, numerous violations were noted during routine inspections and flagged that they needed to be cleaned up. David WQVS960 worked with the local ranger district to develop a compliance plan on behalf of the owner (Henry WQII718), and volunteers with the SWCRS signed up for various workdays to lend a helping hand on site.
August 12 consisted of the following tasks.
- Removal of litter and debris (the site was still heavily littered with shrapnel from the tower collapse)
- Removal of overgrown vegetation on site for fire safety.
- Removal of disused antennas and mounting fixtures from the buildings, which exceeding the allowable impact area of the facility.
- Installation of permanent cable management systems.
- Installation of a permanent (but flexible) antenna racking system.
August 19, 2023 : Compliance Mitigation Day 2
Volunteers:
- David WQVS960 / K6DSA
- Cory WRXR318 / K7RRR
- David WRJF717 / KJ7WWC
August 19 completed the following tasks:
- Removal of the last remaining temporary antennas and tripods.
- Installation of permanent antennas for a last few remaining repeater systems.
- Cleanup and haul-off of building contents not used (clutter).
- Installation of site signage.
September 9, 2023 : Compliance Mitigation Day 3
Volunteers:
- Henry WQII718 / N7HND
- David WQVS960 / K6DSA
- David WRJF717 / KJ7WWC
- Cory WRXR306 / K7RRR
- Glen WROH614
September 9th was the last session of the series, cleaning up and giving the facilities a coat of paint, and realigning a 60ghz microwave dish that provides IP connectivity to the site. The following tasks were completed:
- Realignment of a 60ghz dish to improve internet connectivity on site.
- Preparation and painting of the buildings.
The site is looking much better than it did even before the tower came down at the beginning of this year. Plans are in the works to re-erect a new guyed tower in its place, which is expected to occur in the coming months. The site is fully operational at this time, and things are performing normally – although having a tower would obviously create an improvement.
Thanks for everyone who volunteered for the hard work in turning this site around! We couldn’t have down it without you all!