TrusSteel Flies High at Davis-Monthan Air Force Base

A flight of TrusSteel CFS trusses took to the air above Davis-Monthan Air Force Base (Tucson, AZ) recently. Seven entire sections of the new roof - complete with trusses, bracing, roofing, mechanical systems - landed atop the new dormitory buildings without a hitch (no touch-and-gos needed). "It has gone very smoothly", commented Glenn Lee, Project Superintendent, Sundt Companies Inc.

When asked for reasons for assembling the large sections on the ground and then lifting them to the top plate (a technique called rafting), Kevin G. Almquist, Project Manager, Sundt Companies Inc. replied, "Safety, time, productivity - all those are reasons." When asked about how much time was saved using TrusSteel and rafting, Kevin replied, "Overall, as a conservative estimate for the project, we feel that we have saved two to four weeks". Glenn Lee had his own reasons for liking the rafted installation approach. Glen said, "Safety is a big thing. And, we installed ductwork, sprinklers, chilled water and domestic water piping on the ground. That alone was a big time saver, as opposed to working off ladders and trying to feed all that through the trusses."

Kevin Almquist summed it all up with his comment: "Overall, we are just thinking out of the box."

 More "Out of the Box" Thinking

Alpine Structural Consultants provided engineering assistance for this project. According to Sowri Rajan of Alpine Structural Consultants (ASC), "Kent Bice in the TrusSteel engineering department in Haines City designed the truss bracing for the 50' x 56' sections of the roof system as well as for the big 70' x 70' section. He also designed the locations of the pick points of the raft assemblies as well as the pick lift mechanism and its attachment to the beam supporting the trusses. A HSS 6x2x3/8 tube steel beam (that's a 2" deep x 6" wide x 3/8" thick Hollow Structural Steel section) at both ends of each assembly supported the TrusSteel trusses."

The installation plan, as devised by the installer JB Steel and ASC, was to fabricate the roof section on the ground with the trusses supported by the HSS beams, and lift the section to the top of CMU walls. Kent's design work included the designs for the temporary bracing of the truss bottom chord and the permanent bracing for truss webs. The trusses were spaced at 2' O.C., with approximately 26 roof trusses in each rafted assembly. The roof trusses supported mechanical equipment, which was installed by the mechanical contractor prior to each lift.

 A Famous Site

You can visit the Davis-Monthan AFB on the Web at http://www.dm.af.mil/. Davis-Monthan is the current home of the 355th Wing, one of the largest wings in the Air Force. It is also the home of the famous 12th Air Force, which was started by Jimmy Doolittle in 1942, distinguished itself in Africa during WWII, and continues to serve in recent operations such as DESERT SHIELD and DESERT STORM.

 Contact ASC

 Alpine Structural Consultants provided engineering assistance for this project (truss bracing and location of pick points for raft lifts. To get the expertise of ASC working for you on your next project, click the ASC logo.