3.1 miles of trestle. Mount Washington Railway Company Steam Locomotive #2 "Ammonoosuc" descends the wooden trestle on Cold Spring Hill, and will be bringing the 12 PM summit excursion to a conclusion at Marshfield Station in just a couple of minutes. During fall colors season, this section of track is perhaps the most spectacular, as the trees higher up on the mountain tend to be scrub pines that are just dark green all year long. Speaking of track, this image provides a pretty good look at what the right-of-way looks like all the way to the summit of Mt. Washington. You can easily see here that the track is all built on elevated, wooden trestle, vs. sitting on the ground. This is because the terrain on this mountain is so rough and uneven, that conventional track would never work the way it does at places like Pike's Peak. The use of wooden trestle minimizes the number of points at which the railway contacts the ground. As you can see in this view, most of the trestle is just a couple of feet of the ground, but occasionally, where the ground dips abruptly, taller trestle is necessary. As you might imagine, the amount of taller trestle increases as you go further up the mountain, where there is less vegetation, and a lot more rocky terrain. Each of the trestle bents is numbered, so the crew has a quick way to convey their location when communicating to dispatch at Marshfield Station. The newer diesel locomotives have GPS and always know exactly where they are on the mountain.
There is one more track-fact that may be of interest to Cog Railway fans. For the better part of the last century, this railroad utilized 25 lb. rail (which weighs 25 lbs. per yard.) Those rails were so small that they had to be built up on timbers, to match the height of the cog rail in the center of the track. Over the course of the past couple of years, the railroad has gradually replaced all of that light rail with new, 100 lb. rail, which no longer needs the timber supports. The new rail makes the track simpler and much more robust. It provides a smoother ride for the customers and requires somewhat less maintenance, again because there is just less wood in the structure.
