 Approximately 100 are believed to have been manufactured in the 1960s, 1970s, and 1980s; they are used so rarely that they are generally maintained indefinitely rather than being replaced.For example, in the Boston area the MBTA uses two model RP-3 Portec RMC Hurricane Jet Snow Blowers, nicknamed "Snowzilla", to clear heavy snows from the Ashmont–Mattapan High Speed Line and Wellington Yard.The jet snow blowers can be faster and gentler than conventional removal methods, but consume a large amount of fuel.