Yes lot's of bad history with Wood Bow String Truss Roofs......very short lifespan during a serious Fire once it gets into the Truss area ....not only a Roof Collapse danger but also a danger of end "HIP RAFTERS" pushing a wall over.....info has been written about the dangers by Brannigan in his First Edition back in 1971 but certainly much, much more since the 6 LODDs at the BKLYN Waldbaums Supermarket 8-2-78.......Vinny Dunne on the subject also mentions beside Fire as a danger he relates about a BX NY Truss that collapsed due to a Snow load & wood pieces that rotted due to ...many Supermarkets & occupancies with a large open area (like a bowling alley or a factory, etc) are built with a Wood Bow String Truss Roof.....one of the problems is detection.....depending on the angle you view the bldg you may or may not see the classic hump ( this is the Supermarket in this thread & the classic hump is obvious in the picture but not necessarily from other angles...
https://www.commercialcafe.com/comm...horace-harding-expwy-5850-francis-lewis-blvd/ )....knowing the Bldgs in your normal Response area is important but being able to identify or even suspect this type of Roof where ever you are is paramount....Brannigan's credo which all should follow is "a serious Fire in or under a Truss Roof should not be fought from under or on it".....I would say the key word here is "serious"...... no IC wants to stop an interior attack without good grounds but evaluation & extra caution are important as a Truss has killed.....heavy Fire could be present in an enclosed Truss area without some of the usual heavy Fire indicators like Fire out the windows for example.....I was the Acting Deputy Chief in DV*14 & late one night I responded to a 10-75 in a Key Food Supermarket on Springfield off Horace Harding which had been closed for several hours ....it had a decent smoke condition thruout ....I knew the bldg had a Truss & it was visible from the street & contained in the CIDS info....when I arrived they had not found the Fire yet & Units were inside searching....the BC in BN*53 (Quartered down the block) was an experienced Chief & had been on the scene for awhile but I was concerned thinking of the old "when everything seemed routine ...all of a sudden" quotes in many WNYF articles .....as I was conferring with him a Unit stated on the HT that they had found the source of the smoke in a cardboard compacting unit.....this turned out to be routine but I would say you cannot be too cautious with this type of construction & the various writings & reports on the subject should be a routine subject of Drill & Discussion.... here is a photo of the end of a Truss from the bldg in this thread at 196-35 Horace Harding.....usually these may not be visible but this at the front entrance is certainly a good indicator ....
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