RR museum of pa 6755 side view

this is the last prr m1b mountain type 4-8-2 in the world. it is one of pennsy extremely big steam locomotives coming in around 104 ft long with it's across the country tender. out of 301 built, this is the last survivor. Fun fact, the prr put the keystones on there passenger engines, and the m1a/b was sometimes used for passenger service. this 6755 has a keystone so it was definitely used for passenger trains at one point.