This is a great idea. I had some serious fires and even a serious Subway derailment, and the communications were a real problem. The indecent that comes to mind was the Major Derailment of a subway at the 14th St. Union Square Subway Station, when I was a Lieutenant in Tower Ladder 21. A subway motorman, under the influence, raced through a Switch at very high speed, sending one truck of the lead subway car onto one track and the rear truck onto a separate track. The subway car went through several columns supporting the roadway above and pined the Motormen in the cab of the front subway car. Massive operation and we had to resort to Handi-Talkie relay operations to communicate with the command Post on the street above. Captain Bob Rainey FDNY Engine 26 retired