Still in use more than 180 years after they were built, the Keystone Arch Bridges of western Massachusetts stand as enduring monuments to the skill of their creators.
An economic crisis
Boston had a problem in the late 1830s. The newly completed Erie Canal was drawing more and more trade to the ports of New York and New Jersey, where easy canal access made shipping to the growing interior United States much cheaper. The businessmen of Boston had to do something, or the city would continue to lose trade and economic development and Boston would dwindle. With the Berkshire Mountains standing between Boston and the rest of the U.S., a canal wasn’t an option. This led to consideration of another possibility: a railroad.
At the time, railroads were not seen as a long-range transportation solution. While many railroads were well established by the mid-to-late 1830s, most didn’t cover very long distances. For example, the Boston & Providence Railroad, the first section of which was completed in 1835, operated over a route of 31 miles. A railroad from Boston to Albany, connecting to the Erie Canal, would have to cover almost 200 miles. There was also another major obstacle in the way — the Berkshire mountain range. While not as daunting as the Sierras or Rockies, the Berkshires presented a significant engineering challenge. At the time no railroad had ever crossed a mountain range. This new project would clearly require an experienced railroad engineer, so Major George Washington Whistler was hired to survey and build the railroad.
Whistler was a graduate of West Point, which was the only engineering school in the U.S. at the time. He also had experience with railway engineering, having worked on the construction of several railroads on the East Coast including the Baltimore & Ohio.
Whistler and his team surveyed a route through the Berkshires that mostly followed the Westfield River to help reduce grades. Following the winding and twisting river meant several crossings would be required, which is how the Keystone Arch Bridges came to be.
Building the bridges
Unlike mountain railroads, bridge engineering was well established at the time of the construction of the railway across the Berkshires. The famous Carrollton Viaduct — the oldest railway bridge in the U.S. still in use — had opened on the Baltimore & Ohio in 1829. Whistler had also worked on the construction of that bridge, and incorporated elements of its design into his keystone arch bridges. Both the Carrollton Viaduct and the Massachusetts keystone arches used stone for increased strength and reduced maintenance requirements — an important consideration in the remoteness of Western Massachusetts.
Both used the familiar keystone design to create stone arches that supported the tracks. What made the Whistler’s keystone arches especially noteworthy was their use as part of an over-mountain route, rather than a single crossing of a river. In total, 10 bridges would be required as part of Whistler’s route.
For materials and building expertise, Whistler turned to local Scottish stonemason Alexander Birnie. Stone was brought in by teams of horses and oxen leased from local farmers. Birnie and his team of mostly Scottish and Irish immigrants braved dangerous and remote working conditions to build the 10 bridges, along with other stone structures required for completing the route along the river.
Each bridge began with the construction of stone support pillars at each end of the future bridge. Next, a wooden frame would be built in the shape of the arch between the stone pillars, upon which the stones forming the arch would be laid, finishing with the famous “keystone” in the middle. Now capable of supporting itself with the finished arch, the construction of the sidewalls supporting the tracks could begin. Starting with a wooden frame to place the track at the proper level, stone walls and fill would be added to finish the bridge.
All 10 bridges were built to have the capacity for two tracks, despite predictions the traffic levels would never require more than one. This proved to be a wise decision, as the route added a second track less than 10 years later. The tallest bridge stood 70 feet above the Westfield River. The bridges were so popular and novel that they appeared in postcards and drawings. People would frequently hike and trespass to get a view of the bridges.
Upon completion of the bridges and the route in 1841, the Western Railroad was born. What one skeptic had derisively called “a railroad to the moon” was now carrying freight over the Berkshires. Boston had the answer to the Erie Canal and was saved from economic stagnation. The impacts turned out to be far greater than that, however. This project proved to the U.S. and to the world that the railway was the best way to move freight over land. Soon, canal projects were abandoned in favor of railroads. Whistler himself was summoned to Russia to begin work on a rail line from Moscow to Saint Petersburg. As the U.S. expanded west, the railroad went with it, soon reaching all the way to the Pacific coast. The Keystone Arch Bridges have proven to be a bit of a “keystone” themselves. All the great railways we know today would not have been possible without the work of Whistler and his team laying the foundation of railway engineering, and Whistler’s Western Railway would not have been possible without the 10 arched bridges.
The bridges today
Over time, the Keystone Arch Bridges have passed ownership between the Western Railroad, the Boston & Albany Railroad, New York Central, Penn Central, Conrail, and finally, CSX Transportation. Today, seven of the original 10 arch bridges remain standing. Three were destroyed as part of a catastrophic flood in 1927 that required 11 days of work by New York Central crews to re-open the line. Two arches were abandoned in favor of a 1912 reroute of the tracks that eased the curvature of the line. The remaining five arches are still carrying trains to this day.
Designed in a time when locomotives weighed about 45,000 pounds, the five arch bridges in service today effortlessly support modern 432,000-pound Wabtec ET44AH behemoths, while the abandoned bridges have stood for 111 years without any additional maintenance since their abandonment, and today are popular attractions on the Keystone Arch Bridges Trail.
Maintained by the Friends of the Keystone Arches, the trail is an approximately five-mile walk out and back following the Westfield River through the wooded mountains. The start of the trail allows easy views of the only “double arch” stone bridge, still in use. There are also several locations where the tracks are visible from the trail, which crosses both abandoned arches. While they may no longer carry heavy freight trains, these bridges still provide an opportunity for hikers and railfans to enjoy the scenery of the Berkshire Mountains and see one of the most important and influential pieces of railway history standing today.
