The newest power on the Mt. Washington Cog Railway is this diesel hydraulic locomotive, which emerged from the line's mechanical shop in the summer of 2009. M-3 joined the prototype, M-1, and a sister, M-2 in line service around the 1st of July. On that date, hourly steam-powered excursions were discontinued. The line now runs just one steam trip, on the first train of each day. All subsequent operations are handled by these diesels, unless ridership demands extra sections on more than 30% of the day's trains. Although they lack the charm and historic significance of the steam engines, these diesels have some economic and logistical advantages. They make the trip to the summit in just 40 minutes, yielding a cycle time of just 2 hrs (vs 3 hrs for steam). This means that the railway can handle all operations on most days with just 2 diesels, holding the 3rd engine in reserve. They burn 18 gallons of B20 biodiesel in each ascent, vs a ton of coal for a steam engine. They also start with the push of a button and require only one cab crewmember to operate. The railway is said to be planning to continue construction of more such locomotives in the near future. (Note that the engine in this photo is operating with the cowlings removed. On this day, all 3 diesels operated in the same fashion.)
