The world's first mountain-climbing cog railway has added a B20-powered diesel to its fleet of steam engines. Operated since 1869, the historic Mt. Washington (N.H.) Cog Railway ascends the 6,288-ft. mountain, with a 20-37% grade.

The railway recently added a 12.5L six-cylinder JD Power Tech 6125H B20-compatible diesel engine to its fleet of seven locomotives, according to Diesel Progress magazine. Rising coal prices prompted the historic railroad to add the Tier 2 engine to its fleet of six coal-fired steam engines. The engine is rated 450 hp. At 2,100 rpm, it has a maximum output power of 950 hp.

Of the railroad's three in-season daily 6-mile roundtrips up Mt. Washington, one is B20-powered and the other two are coal-fired steam engines. More than 80,000 passengers ride the railway annually, which climbs New England's tallest mountain. When the railway's builder first presented his idea of building a railroad up the steep peak to the New Hampshire Legislature in the 1850s, they said that he “might as well build a railway to the moon.”