What's on Your Engine #14 - More About LDH Discharges
By President Mark Davis
March 7, 2024

Building on last week's News Story, here is a good example of getting yourself into a jam by forgetting the flow limitation of your engine's discharges. The pumpers at this event were trying to support a 1,000 gpm operation at the attack pumper using a relay pumper over a 2000-ft distance of 5-inch LDH. The source had plenty of available water....that was never the issue. Elevation change was a moot point. The problem was with the pumper shown in this photo...it had no LDH discharge. The 2-1/2" x 5" adaptor was carried on the pump discharge all of the time so when it came time this day to hook up the 5-inch LDH....well, it just got hooked to that 2-1/2" discharge. Everything was just fine until that discharge had to produce a 1,000 gpm+ flow...it couldn't be done. It is easy for this to happen; most of the time we probably don't try and flow 1,000 gpm at a fire. But that ONE time where we needed it.....well....there was a problem. The solution is to figure out how to get two discharges to feed that single, 5-inch LDH. You are gonna have to locate an appliance, get the smaller hoses laid out in position and then shut down the operation to make the change-over. If you have everything ready it should not take too long.