Diesel Debut

In 2008, after 139 years as a steam railway, the Cog took a giant step into the future. We haven’t looked back ever since.

Over 150 years ago, Sylvester Marsh, a modern man of his era, chose the nineteenth century’s state of the art transportation technology to power his unique railway. That was, of course, the steam locomotive, and today, inspired by his spirit of innovation, the modern Cog Railway is doing the same!

When we rolled M1 out of our engine shop in 2008, it marked the beginning of a new era on Mount Washington. The first operational diesel powered locomotive in our history was designed primarily by mechanical engineer Al Laprade (seen in the green shirt at left) and General Manager Charley Kenison (in blue), and was built entirely on-site by the Cog’s shop crew at a cost of $750,000.

Senior Engineer Phil Beroney had the honor of running M1 to the summit for its ceremonial first passenger trip. Proudly wearing its temporary livery Wajo Nanatasis (Mountain Hummingbird in Abenaki) M1 performed flawlessly, and continues as one of our diesel workhorses today.

With the overwhelming success of M1, we ramped up production and averaged the introduction of one new locomotive every 18 months. In 2019, we completed construction of M7, our seventh biodiesel locomotive.

Each of these robust machines is powered by a 600hp John Deere marine engine governed by a computerized operating system. Hydraulic pressure delivers a maximum of 30,000 ft-lbs. of torque to each of two drive cogs beneath the locomotive, pulling the train up the mountain. A redundant air brake system ensures positive braking and parking when needed, but in normal operations, hydraulic pressure is also used to bring the train back down to Marshfield Base Station.

More economical, easier to maintain and environmentally friendlier, it takes anywhere from 18-22 gallons of biodiesel fuel to complete the nearly 7 mile round trip. By comparison, our steam locomotives consume 1000 gallons of water and a ton of coal to make the same trip.

With the completion of the M7 and the continuing use of two completely refurbished steam locomotives, we now operate the largest fleet of locomotives in service in the history of the railway. And M8 is already in the pipeline!

We are exceedingly proud of our fleet of biodiesel locomotives. These powerful machines are leading the way for the Cog to continue to provide one of the world's great rail adventures in the 21st century and beyond.