Mount Tamalpais and Muir Woods railroad photo in front of the Tavern of Tamalpais in 1913. Termed the 'Crookedest Railroad in the World" by many, the passenger cars were dragged up many switchbacks by steam engines. On the return trip from the top, gravity was allowed to propel them down the mountain.
The railroad became famous for its gravity cars – four-wheeled coasters introduced in 1902 that took advantage of the steep, uninterrupted grade. Gravity cars had an operator known as a gravityman who sat in the front-right seat (on most cars) and operated two brake levers that pressed heavy-duty brake shoes against the car's wheels. Gravitymen had strict orders to obey a 12 mile-per-hour speed limit as they glided down Mt. Tamalpais, either to Muir Woods or into Mill Valley. "Gravities" ran at scheduled times, like all trains on the line, essential to safe operation on a single track railroad. Gravity cars were towed back to the summit by the steam engines, where they were stored in the yard for the next run.