As we continue working on the 2013 DHS Grant to study the “Impact of Fire Attack utilizing Interior and Exterior Streams on Firefighter Safety and Occupant Survival,” the second round of testing was conducted at Underwriters Laboratories (UL) headquarters in Northbrook, IL to see how water is distributed within a compartment based on different fire ground tactics. Each test was designed to evaluate the differences in water distribution by testing various application methods, nozzle types and patterns, pressures, and stream location/angles. These tests were completed over a 4 day period with more than 80 tests performed resulting in hundreds of data points as well as hours of video and hundreds of still images.
These experiments were conducted in a single room with attached hallway elevated above the ground in order to allow the collection apparatus to be installed underneath. The elevated structure also allowed for a simulation of a second story room as well as a platform which allowed single story application. The compartment was roughly 10’ 5” wide by 14’ 8” long with a 6’ wide by 8’ long hallway. The structure had two openings; one window (2’ by 4’) on one of the side walls and the other being a doorway (3’ wide by 6’ 8” tall) from the hallway into the room. The openings were to simulate similarly sized openings within structures.
The water collection system used for this round of experiments was a repurposed device known as the Actual Delivered Density (ADD) apparatus. The ADD apparatus collects water in large barrels connected to pressure transducers which allow us to calculate flow rates in given areas within the compartment and ultimately be able to determine how much water made it into every square foot of the room for a given test. This apparatus is typically used to calculate sprinkler densities in other testing conducted at UL’s headquarters. Elevating a compartment above the apparatus and ensuring all of the gaps were sealed and diverted water evenly, allowed the device to be repurposed to suit our needs.
The tests covered a range of hose line sizes including 1-3/4” and 2-1/2” as well as different nozzle types: combination/fog and smoothbore. The application of water varied between smoothbore, straight stream, and narrow fog in addition to different angles into the doorway and window openings as well as different application patterns and water pressures. Nozzle locations were varied to replicate tactics used in the fire service. The nozzle was placed on the ground floor and sprayed into the second floor window to simulate a transitional attack on a second floor bedroom. A platform was placed at the window with the nozzle placed at the base of the window to simulate a transitional attack into a first floor room. The nozzle was placed at the start of the hallway, back from the doorway, to simulate a firefighter advancing a hose line towards the fire room. The nozzle was also placed at the threshold of the doorway to simulate a firefighter reaching the fire room. In each nozzle placement, different stream types and application patterns were used to see if there were any differences in the distribution of the water applied.
These experiments were the second round of tests conducted as a part of the Fire Attack study. Stay tuned for the results to both these and the air entrainment experiments. In the coming weeks, we will be preparing for the full scale fire experiments which begin on February 25th and run through March 18th.