How 195 Workers Died Cutting the Hoosac Tunnel by Hand

Added: 2026-05-22

[00:00:00]195 workers died cutting the Hoosac Tunnel through Hoosac Mountain in northwestern Massachusetts. The tunnel ran 4.75 miles through solid granite.

[00:00:10]Construction took 24 years. The dead were Irish immigrants, American-born laborers, Welsh miners, German laborers.

[00:00:17]They died of black powder explosions, nitroglycerin handling accidents, hoist disasters, rockfalls, lung disease from gunpowder fume exposure. Local Massachusetts people called the tunnel the bloody pit. It is still carrying trains today. 195. The number is precise because the Hoosac Tunnel was a public works project funded by the Commonwealth of Massachusetts after the original private corporation went bankrupt in 1863.

[00:00:43]And the Massachusetts state inspectors and engineers kept careful records throughout the 24-year construction.

[00:00:49]Worker deaths were documented in the inspection reports, the payroll death notices, and the contemporary newspaper coverage in the North Adams Transcript, the Springfield Republican, and the Boston Daily Advertiser. The state inspection records are preserved at the Massachusetts State Archives in Boston, where any researcher today can read the contemporary accounts of the explosions, the rockfalls, the hoist failures, and the cumulative [music] gunpowder fume deaths over the 24 years.

[00:01:16]195 is the count those records support.

[00:01:19]The Hoosac Tunnel [music] runs from the eastern portal at Florida, Massachusetts, through Hoosac Mountain to the western portal at North Adams, Massachusetts. The total length is 4.75 miles. The bore was advanced from both ends, plus a central shaft sunk vertically from the surface of Hoosac Mountain down to the tunnel grade. The central shaft was approximately 1,028 feet deep. Workers descended into the central shaft by hoist cage, worked at the rock [music] face at the bottom, and ascended back to the surface at the end of each shift. The hoist itself, plus the cumulative bore mechanics, plus the explosive handling, plus the ventilation challenges of working a mile or more into solid granite created the four major killing modes that account for the 195 deaths. The four killing eras of Hoosac Tunnel construction tracked the available blasting technology. The first era from 1851 to 1864 used black powder exclusively. Black powder accidents during this period included premature detonations when fuse cords burned faster than expected. Gas accumulation explosions when methane or hydrogen sulfide pockets in the granite were ignited by candle lanterns.

[00:02:27]And ventilation failures that allowed combustion gas build-up in the bore after blasting. Approximately 60 workers died during the black powder era. The second era from 1865 to 1869 marked the transition to nitroglycerin and then to dynamite. Nitroglycerin in its unstabilized form is one of the most dangerous explosives ever used in industrial applications. The Hoosac crews had multiple accidents handling nitroglycerin during the transition period. Including one major accident at the central shaft head in 1867 that killed eight men. Approximately 45 workers died during the nitroglycerin transition era. The third era from 1869 to 1874 used pneumatic drills powered by compressed air piped from the portals plus dynamite as the primary explosive.

[00:03:13]The pneumatic drills allowed faster bore advancement but introduced new accident categories including drill rupture failures, compressed air hose failures, and equipment crush injuries.

[00:03:24]Approximately 75 workers died during the pneumatic drill era, the largest single killing era of the construction.

[00:03:31]The fourth era from 1875 to 1880 was the post-completion legacy deaths from cumulative lung damage and other delayed health effects. At least 15 workers who had survived the active construction died [music] within five years of tunnel completion from documented lung disease attributed to gunpowder fume exposure during their working years in the bore.

[00:03:52]If you appreciate the depth of these American industrial heritage stories and want to support more of them, join at the boss tier for early access and members-only polls, or final boss for member shout-outs and members-only videos. The link is in the description below. Now, we walk through the single deadliest day in Hoosac Tunnel construction. October 17th, 1867 was the worst single day of Hoosac Tunnel construction. On that day, the central shaft hoist cage carrying 13 workers from the bottom of the shaft up to the surface caught fire approximately halfway up the shaft. The hoist cable burned through. The cage fell back down the shaft. All 13 workers were killed.

[00:04:30]The fire had been caused by a kerosene lamp that one of the workers was carrying in the cage. Kerosene was the standard portable lighting in 19th century mining work, and lamp accidents in confined spaces were a known hazard.

[00:04:42]But, the central shaft hoist accident of October 17th was the worst single accident in Hoosac Tunnel history. The 13 workers who died were primarily Irish immigrant laborers, with names recorded as Connor, Sullivan, Murphy, Maguire, O'Brien, Flaherty, Lynch, Donovan, Walsh, Riley, Casey, Kelly, and Hogan.

[00:04:59]Eight of the 13 were married with families. The Massachusetts Public Works Commission paid funeral expenses for all 13 and small lump-sum death benefits to the widows and orphans. The pneumatic drill era of Hoosac construction between 1869 and 1874 was the deadliest of the four eras, despite being technically the [music] most advanced. The pneumatic drill machinery introduced new failure modes that the hand drilling era had not faced. Compressed air hose ruptures threw drill operators against tunnel walls with substantial force, >> [music] >> causing crushing injuries and several deaths. The drill bits themselves shattered occasionally under operating stress, sending fragments of hardened steel through the working face area at high velocity. The pneumatic drill operating noise was loud enough to to [music] hearing over time, and crews working long shifts in the bore developed chronic hearing problems that contributed indirectly to other accidents because workers could not hear warning shouts or shift change signals.

[00:05:57]The combined effect was that pneumatic drill operations, while faster than hand drilling, killed more workers per mile of bore than the slower hand drilling era had. The lung disease that killed at least 15 Hoosac workers in the post completion era deserves separate discussion because it was the slow-motion casualty pattern of 19th century tunneling work. Gunpowder smoke, particularly from the black powder era of 1851 through 1864, >> [music] >> contained substantial amounts of finely divided carbon, sulfur, and nitrogen compounds that penetrated the deepest tissues of the lungs when inhaled.

[00:06:31]Workers who spent years in the bore inhaling gunpowder smoke developed a chronic lung condition that 19th century physicians called miners' consumption or black lung disease. The condition was characterized by progressive shortness of breath, chronic cough, and eventually fatal respiratory failure. The Hoosac workers who survived the active construction often died of this lung disease within 5 to 10 years of tunnel completion. The Massachusetts state health records of the 1870s and 1880s document at least 15 specific Hoosac veterans who died of documented gunpowder fume lung disease. The actual total was probably higher since many workers had returned to their home communities after the tunnel completion and their deaths were recorded in local parish records rather than in state health archives. The hoist system at the central shaft was the most dangerous single piece of equipment in the entire [music] construction operation. The shaft was approximately 1,028 ft deep with a cable hoist operated by a steam engine at the surface. The hoist carried workers, supplies, [music] and rubble between the surface and the working face at the bottom of the shaft.

[00:07:38]The cable was approximately 1 and 1/2 in in diameter made of wrought iron strands wound around a hemp core.

[00:07:45]Cable failures were a constant hazard throughout the construction. The October 17th, 1867 disaster was the worst single hoist incident, [music] but smaller hoist incidents occurred regularly.

[00:07:56]Three additional cable failures between 1870 and 1874 killed nine workers in three separate incidents. After the October 17th disaster, the Moffitt Tunnel Commission, which by that point had taken over Hoosac construction from the original Troy and Greenfield Railroad, replaced the hoist cable on a strict 6-month replacement schedule, rather than waiting for visible wear.

[00:08:19]The protocol significantly reduced subsequent hoist failures, but did not eliminate them entirely. The workers who died at the Hoosac Tunnel were drawn from the standard 19th century American mining labor pool. Approximately 60% of the Hoosac labor force was Irish-American, recruited primarily from the famine immigration wave of the 1840s and 1850s. The Irish workers came to Hoosac from earlier construction work on the Erie Canal in Upstate New [music] York, the Pennsylvania Anthracite Coal Mines, the New York Croton Aqueduct, and the Boston water supply tunnels. By the 1860s, the Irish-American labor pool for hard rock tunneling was the largest single immigrant labor population in the United States. The Hoosac project absorbed approximately 1,000 Irish workers at peak employment, organized into crews of 15 to 20 men under Irish-American foremen. Approximately 30% of the Hoosac labor force was American-born. These workers came primarily from the western Massachusetts and southern Vermont rural population.

[00:09:19]Many were former farm laborers who had taken construction work for higher wages than agricultural employment offered.

[00:09:25]American-born workers tended to occupy the supervisory and skilled trade positions, including the carpenter crews, the machinist crews, and the senior blasting foremen. The remaining 10% of the Hoosac labor force was a mix of Welsh, Cornish, [music] and German immigrants with smaller numbers of Italian and Scandinavian workers. The Welsh and Cornish workers brought hard rock mining experience from the British Isles.

[00:09:48]>> [music] >> The German workers brought experience from the Central European mining and tunneling traditions. If you are new here and enjoying this kind of historical depth, subscribe so you do not miss the next video. We publish two videos per day this week. Now we walk through the named engineering supervisors and contractors who managed the 24-year project. The Hoosac Tunnel construction passed through several different management arrangements during its 24 years. The original Troy and Greenfield Railroad began the work in 1851 under Chief Engineer Herman Haupt, a young Pennsylvania trained engineer who had studied at West Point. Haupt managed the first few years of construction using the standard black powder hand drilling methods of the era.

[00:10:29]He left the project in 1861 to take a senior engineering position with the Union Army during the Civil War, where he supervised railroad and bridge engineering for the federal forces.

[00:10:40]After the original Troy and Greenfield Railroad went bankrupt in 1862 due to slower than expected progress and cost overruns, the Commonwealth of Massachusetts assumed financial responsibility for the project.

[00:10:52]Massachusetts appointed Charles Storrow as Chief Engineer in 1863. Storrow had been involved in the Lawrence, Massachusetts Canal and Dam construction during the 1840s [music] and had a deep knowledge of 19th century hydraulic and rock cutting engineering.

[00:11:08]Storrow managed the Hoosac Tunnel through its most difficult period, from 1863 to 1868, including the transition from black powder to nitroglycerin [music] and then to dynamite. Storrow personally argued for adopting the new explosive technologies despite the danger on the grounds that the alternative was 20 more years of black powder bore at the cost of perhaps 300 [music] more worker deaths. The argument was bitterly debated among Massachusetts state engineers and the public, but Star 0 1 and the Hoosac became one of the first major American tunneling projects to systematically deploy nitroglycerin and dynamite. In 1868, the Commonwealth of Massachusetts contracted the remaining tunnel work to Walter and Francis Shanly, two brothers from Quebec, Canada, who ran a successful contracting firm. The Shanlys had completed major canal and tunnel work in Canada and had a reputation for finishing projects on schedule. The Shanly contract specified that the Hoosac tunnel would be completed by 1874 for a fixed price. The Shanlys met schedule >> [music] >> essentially on time with the bore completed in 1874 and the final tunnel finishing work completed in 1875. The first scheduled rail traffic ran through the tunnel on February 9th, 1875.

[00:12:22]Walter Shanly later wrote a detailed engineering report on the Hoosac construction that became the standard reference for late 19th century American mountain tunneling projects. His report is preserved at the University of Western Ontario archives.

[00:12:37]The Hoosac tunnel cost the Commonwealth of Massachusetts approximately $21 million in the cumulative 24-year construction budget. In 1875 dollars, that figure was equivalent to roughly 420 million today.

[00:12:50]The Massachusetts state debt issued to [music] fund the tunnel was repaid through bond revenues and through rail traffic tolls collected from the operating railroads that used the bore.

[00:13:00]The Troy and Greenfield Railroad, reorganized as the Fitchburg Railroad after the bankruptcy proceedings of 1862, operated the tunnel from 1875 until the Boston and Maine Railroad acquired the Fitchburg [music] in 1903. The Boston and Maine operated the tunnel from 1903 until corporate bankruptcies of the 1970s. The Pan Am Railways consortium acquired the Boston and Maine assets in the early 2000 and [music] now operates the Hoosac Tunnel for freight rail traffic. The nitroglycerin transition era of 1865 through 1869 deserves separate detailed description because the Hoosac was the first major American tunneling project to use nitroglycerin systematically. Nitroglycerin had been invented by the Italian chemist Ascanio Sobrero in 1847, but the compound was so unstable in its pure form that it had been considered too dangerous for practical industrial use for the next 16 years. The Hoosac engineering staff under Charles Storrow began experimenting with nitroglycerin in 1865 as a more powerful [music] blasting alternative to black powder. The early experiments included on-site manufacture of nitroglycerin at temporary chemistry sheds near the tunnel portals since transporting nitroglycerin in finished form was considered too dangerous.

[00:14:16]Chemist George Mowbray, hired specifically for this work, developed a relatively safer on-site manufacturing procedure that produced approximately 100 lb of nitroglycerin per day for the active blasting [music] operations. The on-site nitroglycerin operations were still extremely dangerous. Three separate nitroglycerin handling accidents at the Hoosac between 1865 and 1869 killed a total of approximately 25 workers, including the central shaft [music] head accident of August 11th, 1867 that killed eight chemistry shed workers when a temperature control failure during nitroglycerin manufacture caused a complete batch detonation. The chemistry shed and most of the supporting infrastructure were destroyed. The bodies were not recovered intact. The Hoosac construction continued [music] the on-site nitroglycerin manufacture despite the accidents because the productivity gained from nitroglycerin blasting versus black powder blasting was substantial. A nitroglycerin charge could break six to 10 times more rock per shot than an equivalent black powder charge. The transition from nitroglycerin to dynamite at the Hoosac occurred in 1868, shortly after Alfred Nobel's stabilization patent made dynamite commercially available in the United States. Dynamite was substantially safer to handle than pure nitroglycerin because the stabilizing matrix prevented accidental detonation from mechanical shock or temperature variations. The Hoosac switched from on-site nitroglycerin manufacture to dynamite supply through commercial explosive vendors within a year of dynamite's commercial availability. The chemistry sheds were shut down. The accident rate from explosive handling dropped substantially after the dynamite transition, though the cumulative casual count from blasting accidents remained the largest single category of Hoosac fatalities throughout the construction.

[00:16:03]The Western Gateway Heritage State Park in North Adams, Massachusetts preserves the memorial documentation for the 195 worker deaths. The park is located at the western portal of the tunnel and was established in 1985 by the Commonwealth of Massachusetts as a public commemoration of the construction history. The memorial includes a list of all 195 documented worker names where the records preserve the names, the date of each fatal accident, >> [music] >> the cause of death were determined, and the workers' known ethnic background and family information where the contemporary records included that information.

[00:16:40]About 120 of the 195 names are individually preserved with full biographical information. The remaining 75 workers are listed by surname only or by Irish-American identification with approximate dates. The pneumatic drill innovation that arrived at the Hoosac in 1866 deserves a separate description because the Hoosac was the first major American tunnel to systematically deploy this technology at scale. Charles Burleigh of Massachusetts patented the first commercially viable pneumatic rock drill in 1866 building on earlier European designs developed for the Mont Cenis tunnel construction [music] in the Alps. The Burleigh drill was a handheld pneumatic hammer drill powered [music] by compressed air piped from a steam-powered compressor at the tunnel portal. The drill could bore a powder hole through granite in 3 to 5 minutes versus the 15 to 30 minutes required for hand star drilling. The Hoosac engineering staff under Walter Shanly adopted Burleigh drills in 1866 and began training workers on the new equipment. Within 2 years, the Burleigh drill had replaced [music] hand hammer drilling on most of the active bore faces. The compressed air infrastructure required to support pneumatic drilling at the Hoosac was substantial. The construction included two major compressor plants at the east and west portals with each plant containing multiple steam-powered air compressors connected to coal-fired boilers. The compressed air was piped from the portal plants along the tunnel floor through iron pipes [music] ranging from 2 to 6 in in diameter. The piping system extended for over 4 miles inside the bore at peak operation with branches connecting each individual drill operator to the central compressed air supply. The total cost of the compressed air infrastructure including compressor plants, piping, drills, and associated equipment exceeded $600,000 in 1860s dollars equivalent to roughly 15 million today. The investment paid for itself in approximately 18 months through increased bore [music] advancement rates. The Walter and Francis Shanly contracting firm that completed the Hoosac construction [music] between 1868 and 1875 had emigrated from Canada to the United States specifically for the project. The Shanly brothers had built their reputation on Canadian canal and tunnel work during the 1850s and 1860s including major work on the Welland canal expansion and on several railroad tunneling projects in southern Ontario.

[00:19:04]The Shanly contract for the Hoosac was structured as a fixed price arrangement with completion bonuses tied to specific milestones. The brothers personally supervised the construction with Walter running the day-to-day operations from a headquarters near the East Portal and Francis handling the supply chain and labor recruitment from offices in New York City. The Shanlys met essentially all of the contract milestones, completing the bore in 1874 and the finished tunnel in 1875.

[00:19:33]Walter Shanly later wrote a detailed engineering memoir of the Hoosac construction that became the standard reference for late 19th century American mountain tunneling. The Hoosac Tunnel as a working piece of infrastructure has been continuously in service since February 9th, 1875.

[00:19:49]The bore has not failed in any major structural sense in 150 years. Periodic maintenance has included replacement of the original wooden timber supports with steel arches in the unstable rock zones, replacement of the original brick lining in damaged sections with cast-in-place concrete, modernization of the ventilation system, and electrification of the tunnel lighting. The basic granite bore that the 195 [music] workers died cutting is still the same granite bore the trains pass through today.

[00:20:18]The walls are the same walls. The ceiling is the same ceiling. [music] The track has been rebuilt many times, but the rock around it is the same rock that absorbed the black powder, nitroglycerin, and dynamite blasts of 1851 to 1875.

[00:20:32]>> [music] >> Anyone who has seen the masonry on a 150-year-old tunnel knows this. The Hoosac is not just a piece of transportation infrastructure. It is a memorial to a generation of American mining laborers who took on a single engineering project at the limit of 19th century technical capability and paid for that project with their lives. 195 is a precise number. It is also a small fraction of the broader American mining and tunneling labor mortality of the 19th century. The Hoosac is precisely documented because it was a public works project with state oversight. Most pre-modern American tunneling and mining mortality was less well documented in private commercial operations with worker deaths treated as routine industrial accidents that [music] did not consolidate into engineering records. The Hoosac numbers are precise.

[00:21:19]They are also probably representative of broader patterns that are now lost to the historical record. The North Adams, Massachusetts community that surrounded the Hoosac Tunnel West Portal developed a particular relationship with the construction over the 24 years of work.

[00:21:35]North Adams in 1850 had a population of approximately 3,000. By 1875 when the tunnel opened, the population had grown to approximately 17,000 with much of the growth attributable to the tunnel construction labor force and the associated commercial and service infrastructure.

[00:21:53]The town economy during the construction years was dominated by tunnel related employment, supply contracts, and the various support businesses that served the tunnel workers and their families.

[00:22:04]The Irish-American Catholic community of North Adams established St. Anthony's Catholic Church specifically to serve the tunnel workforce with the church dedicated in 1866.

[00:22:14]St. Anthony's parish death registers preserve the names of approximately 70 of the 195 tunnel workers who died during construction providing some of the most detailed biographical records of the worker casualty count. The political support for the Hoosac Tunnel construction in the Massachusetts state legislature was sustained over the 24 years through a particular coalition of Western Massachusetts political interests and Boston commercial interests. The Western Massachusetts political faction wanted the tunnel because it would open Western Massachusetts and the Hudson Valley [music] to direct rail commerce with Boston ending the regional economic isolation that had characterized the area before the tunnel. The Boston commercial interests wanted the tunnel because it would extend the Massachusetts Bay rail trade westward to the Great Lakes region and the Midwest, [music] allowing Boston to compete with New York City for inland commerce. The combined coalition pushed the state legislature to continue funding the tunnel through multiple budget cycles.

[00:23:14]Even when construction was substantially behind schedule and over budget.

[00:23:18]The coalition was sustained throughout the construction by skilled political work from successive [music] Massachusetts state governors and from the Western Massachusetts congressional delegation. The cumulative cost overrun on the Hoosac Tunnel construction was substantial. The original [music] empty estimate was approximately $2 million and 3 years of construction. The actual final cost was approximately $21 million >> [music] >> and 24 years of construction. The cost overrun was driven by the technical challenges of granite tunneling that had been underestimated in the original specifications, by the transitions [music] to nitroglycerin and then dynamite that required infrastructure investment in chemistry sheds and compressor systems, by the original Troy and Greenfield Railroad bankruptcy of 1862 that forced the Commonwealth of Massachusetts to assume the project, and by the various delays from labor disputes, supply chain problems, and political battles over funding.

[00:24:15]The cost overrun was nonetheless considered acceptable by the Massachusetts political and commercial elite of the 1870s because the completed tunnel provided benefits that justified the investment.

[00:24:26]The local nickname for the Hoosac Tunnel during construction, the Bloody Pit, persisted in Northwestern Massachusetts [music] for several generations after the bore opened.

[00:24:36]Residents of North Adams and the surrounding towns referred to the tunnel as the Bloody Pit through the late 19th century and well into the 20th. The name appears in regional newspapers, in local oral histories, and in the personal correspondence of late 19th century Western Massachusetts residents. The nickname captured both the horror of the death toll and the regional pride in having completed the project despite that toll. By the mid-20th century, the nickname had mostly faded from common use, replaced by the formal name. But, it appears in modern historical writing about the tunnel, and it is preserved on signs and informational displays at the Western Gateway Heritage State Park.

[00:25:14]Before we close, if this kind of pre-modern engineering story is what you came for, the final boss tier at $9.99 gets you members-only videos, plus your name in upcoming uploads. Boss tier at $4.99 for early access. Link in the description. Thanks for watching to the end. The Hoosac Tunnel is still in active rail service today, 150 years after the first scheduled train passed through the bore. Pan Am Railways runs scheduled freight traffic through the tunnel daily. The Western Gateway Heritage State Park in North Adams, Massachusetts, preserves the memorial documentation for the 195 workers who died cutting the bore. The Irish immigrant workers, the American-born laborers, the Welsh miners, the German workers, the Cornish miners, the Italian laborers, the Scandinavian workers.

[00:26:00]Their names are on the plaque at the park, in the rolls of the Massachusetts State Archives, in the historical records of the Catholic parishes of North Adams and Florida, Massachusetts, where many of them are buried. They cut the longest tunnel in the Western Hemisphere through solid granite by hand and explosive over 24 years. They are mostly anonymous to the broader American historical memory. The tunnel they cut is still there. Trains still run through it. Local Massachusetts residents called the tunnel the Bloody Pit during construction. The name endured. The records prove it.