Do not know of any. Safe productivity is the name of the game. They are not mutually exclusive events. In reference to active fire line. 3 person engines are inherently inefficient and that can lead to safety issues. Look at the staffing. Person 1 needs to be heads up, supervising, and focused on the big picture to keep persons 2&3 safe. Person 2 is focused on the operation of the apparatus or keeping a consistent reliable water stream flowing. That leaves person 3 (lowest paid usually) to put water on the fire. So for about 300 feet that may work. After that they are over extended. 300 feet ain’t no’thin. When one cuts the 4th person they are cutting 50% of the actual fire fighting productivity of that module (there is your data). Then there is the expectation of the people you are going to assist. Are they paying for 3 or 4 or 5 on an engine. Your Chief no doubt is viewing this whole matter thru the frosted lenses of budget. If one of your agencie’s decision makers’ house, business, or range goes up in smoke because of the lack of that 4th person we can only hope they see the connection. Sorry, twitter was never my game.