I work for a 3rd party aerial inspection and testing company, American Test Center, and am involved in technician training, especially for ground ladder inspections and testing. I am also the ground ladder testing equipment project manager and have recently updated our physical equipment for ground ladder inspections and testing.
My technical question pertains to the correct heat sensor placement and heat sensor quantity on multipurpose ground ladders (Type 1AA & 1A), used in ever-growing numbers of fire departments we service.
No offense intended, but in our view, and that of a significant number of our customers, the wording used in the current code, NFPA 1932 - 2015 Edition, Chapter 6, Section 188.8.131.52.4, is open to interpretation which causes confusion with our fire department customers about the quantity of heat sensors to apply to this ladder type. One reading of the code suggests there should be a total of 8 heat sensors per ladder and the alternative reading suggests a total of 12 heat sensors per ladder. Comparisons between a typical 2-section 24' extension ground ladder, with its 8 heat sensors properly placed, and a 22' multipurpose ground ladder with 8 heat sensors properly placed makes sense to the majority of our customers. However, if the code's intent is to require 12 heat sensors per multipurpose ground ladder, it seems excessive to our customers and also to us. I'm estimating the average opened length of multipurpose Type 1AA and Type 1A ground ladders used in fire departments around the country is somewhere between 13' & 22', and it's likely the 13'-17' lengths are the most common subset, which better fits the logic of applying 8 heat sensors instead of 12 to multipurpose ground ladders.
My request is two-fold: firstly, to confirm with the code writers the correct quantity of heat sensors to apply and secondly, to request consideration for an internal review of this issue by the NFPA technical group and possible re-wording of this specific section for better understanding and compliance.
Thank you and Take Care,
American Test Center