Alpine Tunnel: The Problem of Clearance, part 1

part of a map from the VHS of the video inside the tunnel

Back in 1992, a group of people took a film crew into the Alpine Tunnel.  While I had seen many photos
of the tunnel’s abandoned interior, this video footage truly gave the sense of the tight inky blackness of being inside the fabled bore.  Yet, the narrow confines of walking the tunnel are no comparison to trying to operate full-sized narrow-gauge trains through it as a recent reread of a few pages of Colorado Annual 12 made clear.

A laundry list of problems plagued the Hancock to Quartz segment of the C&S including long stretches of 4% grades, long winters at altitudes above 10,000 feet, rock slides on the western side of the pass, and lack of sun to melt the snow on the east side along with much drifting of the dry snow.  The missing sunlight on the eastern slopes did, however, reach the higher mountain peaks creating slushy snow that eventually came down the mountain onto the track.  One other problem not related to grades or weather, though, was that of clearance in Alpine Tunnel itself.

A display mirroring the tunnel's arch

The Alpine Tunnel was a mere 14 feet high above the rails.  This left just a little over a foot of distance to the ceiling above many locomotive smoke stacks and roughly 24 inches above boxcar brake wheels.  By comparison, these clearances were two or more feet smaller than those of most snowsheds on the line.  The width was similarly tight: 2 1/2 feet less in width than other C&S bridge structures or snowsheds.

One quickly wonders what brakemen who were needed on the top of cars to turn the brake wheels were to do in this circumstance, particularly considering that eastbound trains had the double danger of going downhill once passing the apex of the tunnel and then facing a sharp 24-degree curve just outside of the east portal.  Since the tops of high cars was out of the question due to the height restriction, brakemen chose to find two gondolas with brake wheels on adjoining sides.  This allowed them to do what is called “double brakes” (though, this didn’t keep them from the inevitable smoke inhalation of the belching locomotives).  Still, many trains exiting the east portal were out of control.  It could take all three miles from the tunnel to Hancock to finally stop a train.  Of course, some were not so lucky and left the rails.

A westbound train at the west portal station. 
From Historic Alpine Tunnel by Dow Helmers

Part 2 of this exploration will be posted in the next few days.