Exposing Fire Service Hose in a Flashover Chamber

At the request of the Fire Department City of New York (FDNY),  UL’s Fire Safety Research Institute (FSRI) instrumented and documented a series of 12 thermal exposure hose experiments in the burn compartment of an FDNY flashover simulator and observed the performance of fire hoses exposed to the heat flux from flaming hot gas layer conditions above the hose. FDNY supplied a variety of hose types that represent a cross section of commercially available materials and construction methods.  The thermal exposures generated in the burn compartment were measured until the hose being examined began to lose water through the wall of the hose. All of the hoses lost water through their wall, although the size of the holes and the amount of water leakage vary. 

Context

The design and the materials used in fire hose construction are ever-changing. A variety of synthetic materials and construction methods have replaced legacy designs which used cotton jacketing and a rubber lining. When comparing legacy designs with current hose designs, noticeable advantages are reduced weight or less friction loss. However, there are concerns regarding line of duty death and line of duty injury incidents where hose burn through may have been a factor. In response to these concerns, a radiant exposure test was added to ANSI/UL 19 Lined Fire Hose and Hose Assemblies.  NFPA 196, Standard on Fire Hose requires that attack hose sizes 1 ½ in  to 3 in shall be tested in accordance with the ANSI/UL 19 radiant heat test and conductive heat test. 

Objectives

There were several key objectives associated with the experiments conducted:

• Measure the thermal exposure to fire hoses that represent a range of the commercially available materials and construction methods.
• Record the time to first perceptible water leakage.

• Examine the repeatability of the thermal exposure created within the burn chamber of the flashover simulator based on the standard fuel load.
• Characterize the impact of the leakage on the flow of water to the nozzle.