The Bowstring Truss

The Bowstring Truss

_bowstringThere’s a tremendous lack of understanding in the American Fire Service as to what accurately defines and comprises a Heavy Timber Bowstring Truss and the Operational and Safety Precautions that must be recognized, implemented and trained on, in order to achieve and maintain operational excellence, company integrity and firefighter safety on the fireground.

All bowstring trusses are not created equal and do not share the same characteristics when found in a building and occupancy.

They may have the same shape, but shape alone does not define the bowstring truss.

Based on the type, design, construction, materials, age, span, spacing, configuration, occupancy and application there are vast differences AND similarities.

There are significant differences in terminology when referring to them and tactics that should be employed on the fireground- and yes there are prominent differences between east coast and west coast types and tactics.

The Bowstring Truss- They are not All the Same: Do you know what they are? These truss components and systems have varying levels of Predictable Performance under fire conditions, Building RIT: Resiliency- Integrity-Time and operational profiles that may allow or restrict particular tactical deployments and task assignments.

Photo: CJ Naum/ Buildingsonfire

Photo: CJ Naum/


We’re working on a comprehensive white paper with on-line accompaniments that will provide uniformity and clarity on the subject and the much needed continuity so we are talking the same language. We’ll be rolling out a comprehensive training program on this building construction system, occupancy risks with corresponding tactical and operational considerations for improved incident operations, company integrity and personnel safety.

As part of a planned roll-out on the Buildingsonfire FACT series, look for informational forms on Reading the Building that we’re in the final stages of production. Look for future announcements later this summer.

The lessons from the fireground resonate with learnings from near-miss close calls and the continuing preventable line of duty deaths from subsequent operations at similar structures and occupancies.

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Let me offer the following terms that some of you may be familiar with-in your world.


Here are some Bowstring Type Truss terms:

  • The Heavy Timber Bowstring Truss,
  • Arch-Rib Bowstring Truss,
  • Laminate Cord Bowstring Truss,
  • Lattice Bowstring Truss,
  • Easybow Truss,
  • Mack Truss,
  • Summerbell Bowstring Truss,
  • Mono-chord Bowstring Truss
  • Duo-Chord Bowstring Truss,
  • Segmental Multi-Cord Bowstring Truss,
  • Tension Rod Bowstring Truss,
  • Bowstring Arch Truss,
  • Bowstring K-Truss,
  • Split-Ring Bowstring Truss
  • TECO Bowstring Truss

To name a few. Do you the Difference in each of these types of Bowstring Truss systems, configurations and construction methods?

They may share a common shape, BUT have differences that are unique to the region, methods of material, occupancy application and use….


We’ll be posting more on this timely subject on both, Buildingsonfire and on under the Modern Fire Attack. Look for periodic posts and pics on Buildingsonfire on Facebook. Stay Tuned

Some Lessons from the Fireground




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