Hoosac Tunnel
What were the significant challenges in constructing the Hoosac Tunnel?
What innovations were used in the construction of the Hoosac Tunnel?
Why is the Hoosac Tunnel referred to as the Bloody Pit?
Hoosac Tunnel, railway tunnel that runs through Hoosac Mountain of the Berkshire Hills, east of North Adams, Massachusetts, the first major rock tunnel built in the United States. Hoosac Tunnel was built to provide a rail connection between Boston and upper New York state.
History
The Appalachian Mountains, running southwest from Newfoundland and Labrador in Canada to central Alabama, pass through Massachusetts as the Berkshire Hills. Until the 19th century, this geographical feature hampered trade to Massachusetts from New York, the region’s principal commercial hub in the 1800s. Trade ran through the city of Troy in New York, from which the only routes into Massachusetts and eastern New England in general were forced to bend far to the south around the imposing Hoosac Mountain in the Berkshire Hills. The economic setback from the long detour was significant enough that, in 1819, a canal through Hoosac Mountain was proposed to shorten trade routes so Boston, on the eastern coast, could be connected to the Hudson River, routing goods through a much shorter path. Surveys to determine the course of the project began in 1825, and a viable route was identified. Even as the technical challenge of boring through the mountain remained a source of skepticism, work began on the first American railroad, the Baltimore and Ohio, chartered in 1827. The success of the new transport medium was such that the plan to bore a canal was canceled as new railway modes of transport and trade gained traction.
The idea of crossing the Hoosac Range resurfaced in the 1840s. Some sources credit Alvah Crocker, a Massachusetts paper mill owner, with advocating for a railroad; other sources say he presided over a session in which the decision to begin work on the tunnel was taken. The proposal involved drilling a rail tunnel about 5 miles (8 km) long directly through Hoosac Mountain—an unprecedented and technologically difficult undertaking for the period.
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In 1848 the Troy and Greenfield Railroad Company was created to take on the project. It initially built a tunneling machine to bore into the mountainside, but this failed, and the general pessimism of investors toward the project resulted in stagnation as the company petitioned for funds. A grant of $2 million by the state spurred work in 1854, but friction between the firm and its contractors, under the direction of Herman Haupt, meant that only about 0.8 mile (1.28 km) of the tunnel was dug by 1863. Haupt eventually left the project in 1861 as Troy and Greenfield went bankrupt and the state took over the site, with chief engineer Thomas Doane overseeing operations for about six years. The Canadian engineers Walter and Francis Shanly of Montreal took on the final stages of the project and saw it through to completion, with the first train passing through the tunnel in 1875 and the final touches on the project cemented in 1877 with the erection of the eastern portal facade.
Construction: Challenges and innovations
The Hoosac Tunnel took about 24–26 years to complete. In addition to the project’s financial and operational challenges, the technologies used for boring and tunneling in the initial stages of the project were not advanced enough to easily mine through the hard gneiss and quartz of Hoosac Mountain. In fact, the project came to depend heavily on the introduction of what was then cutting-edge excavation technology: In its later stages, the project saw the first use of many different types of tools and machines that helped advance tunneling. Two chief innovations were the first broad industrial use of nitroglycerin detonated using electric firing and the employment of advanced compressed-air drills.
George Mowbray, a North Adams chemist, had followed European work on nitroglycerin with interest. In 1866 he developed his own method for using the chemical and employing it on-site for industrial applications. Called trinitroglycerin, this modified form proved important to the rapid progress of the Hoosac Tunnel project. Doane used an electric firing method to detonate the explosive from a safe distance, though the sensitivity and unfamiliarity of these techniques led to accidents that claimed the lives of workers.
Even the explosive chemical, though, was hampered by the basic hand-drilling techniques used on-site, and Mowbray requested that the engineers employ means to bore deeper holes so the explosive could sit deep enough to be more effective. Another 1866 invention, the Burleigh drill, invented by engineer Charles Burleigh, came into the picture. Using compressed air rather than physical power or steam to drive a central piston, the Burleigh was faster than other drills. The use of a dozen of these drills at a time, in conjunction with trinitroglycerin, helped engineers make quick progress on the Hoosac Tunnel.
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Some believe the Hoosac Tunnel is haunted. Between 1851, when the project began, and 1875, when significant boring was completed, about 195 workers died. The tunnel acquired a macabre reputation, and it came to be called the Bloody Pit.
Apart from scaffolding mishaps and cave-ins, the deadliest incident occurred when a leaking naphtha lamp caught fire in the central shaft and exploded in October 1867, killing 13 workers.
Legacy
After its completion, the Hoosac Tunnel provided a shorter and more direct rail route between Massachusetts and New York. First operational in 1875, the tunnel became a critical railway stop, facilitating the movement of freight and passengers between New England and the Midwest. Passenger service through the tunnel continued into the mid-20th century, but, in 1958, the line was converted to a freight-only service.
The tunnel remains in use today as part of a freight corridor that has been operated by Pan Am Railways (acquired by CSX Corporation in 2022) since 2009. It also functions as a milestone of industrial progress in New England, and in the United States in general.