That's a great looking FF unit there! 5500gpm is a pretty good capacity too. The last ship I was stationed aboard (Rescue & Salvage vessel), and sister ship to the one they used in "Men of Honor", had a 2000gpm salvage pump in addition to the other pumps aboard. With the 2000gpm pump we would feed three 2.5" hoses connected to the deluge gun on the top deck. That puppy could shoot a stream of water a looong way! 8)
In the pic of the Philly unit, it appears to have a sloped rear deck (for launch/recovery) of an inflatable boat on it, but hard to tell in the pic.