The Shafts of the Hoosac Tunnel


Courtesy of North Adams Public Library

“…based on an assumption of four miners and four drillers working continuously, twenty-four hours a day, on only the two [portals]– led to the conclusion that Haupt would need twenty-two years before the east and west headings of the Hoosac Tunnel would meet. The estimate of the time matched perfectly with an average advance of two feet per day and areas working crews working six days per week.”


During construction of the Hoosac Tunnel, especially in the West Portal, mining was incredibly difficult. Today, we have large mining drills which can create tunnels almost instantly. We have mastered the use of explosives, especially which explosives are unstable, and which are better used for creating holes or paths in rock.

In the mid-1800s, the Berkshires were only just beginning to understand the use of explosives such as nitroglycerin, as well as large scale mining.  Miners progressed through the tunnel with the help of black powder being loaded into the hand drills that were being used at the time

Courtesy of the North Adams Public Library

The process of drilling was no easy feat by any means. To complete this tunnel would require intense, and continuous, manpower.  With the difficulties the West Shaft presented the workers, advancement of the tunnel was often halted. When the West Shaft reached only 260ft, workers came across soft ground that prevented further advancement. To make matters worse, in February of 1866 3 months of hard labor had been lost in a fire.

Workers faced the unfortunate task of  realigning the tunnel after work had already been performed. The West Portal and West Shaft were on one line, and the East Portal on another, just passing had they tried to continue straight through. The decision was made to intersect through the West Shaft instead of creating another 300-foot hole and have the new line continue through to the East Portal.

An additional roadblock for workers was an unexpected flood that resulted in the creation of an 8 by 15 ft shaft that had to be built about 264ft west of the West Shaft to properly remove the water, delaying their progress.


The Central Shaft is located halfway between either ends of the tunnel, earning it its given name. The shaft was created to help speed efforts in building the tunnel, believing that once the shaft reaches level with the portal, it would enable workers to construct the tunnel from both directions.

The Hoosac Tunnel’s Central Shaft is located not quite halfway between the two portals. A location of much death, the Central Shaft is home to one of the tunnel’s most tragic accidents. The construction of the tunnel was overseen by Thomas Doane, and a wooden building was created as the shaft grew in length.

In 1899, a steam-powered fan was eventually installed to the top of the shaft to help air filtration, as the fumes inside the tunnel were becoming problematic for the miners.

“The Central Shaft Explosion.” Courtesy of North Adams Public Library

Workers were in the process of digging the vertical shaft when a candle ignited the fumes being leaked into the area resulting in an explosion that would drop the hoist the workers were on into the shaft. There was a singular effort made to try and rescue the men but the fumes were too strong for anyone to go down into the shaft. The 13 men who had fallen had initially survived and created a raft to keep from drowning but eventually died from the toxic fumes. Their bodies were found several months later.

Courtesy North Adams Public Library


First of its kind in the United States, the Nitroglycerin factory nearby the West Shaft was used to create explosives to aid in the construction of the Hoosac Tunnel. Many lives were lost in the use of Nitroglycerin due to the unstable nature of the explosive.

The factory was built by George Mowbray, a professor with whom had much experience with the explosive. The factory was running by December 31, 1867, the Hoosac Tunnel being the first construction job to use the Nitroglycerin.

Courtesy of the North Adams Public Library



Continue on by reading more about the lives lost in the tunnel with Death>>