The highlight of the Stone Arch Bridge route is a visit to a magnificent railroad bridge built in 1872 in Westford. We also travel along the old Nashua, Acton and Boston railroad grade in both Westford and Groton. To complete our railroad tour, we will ride a part of the Fitchburg and Lowell Street Railway grade and visit the historic Graniteville section of Westford.

This route starts at the Cow Pond Brook soccer fields (PortaPotty equipped) in Groton. The map below isn’t completely accurate since Cow Pond Brook Drive continues past Hoyt’s Wharf Road to the soccer fields. Click on the map below to go to MapQuest for directions.

We discovered during our “guinea pig” ride that there is no sign for Cow Pond Brook Drive on Route 40. Look for Town of Groton Transfer Station signs, that is Cow Pond Brook Road. If you are coming from Groton on Route 40 and see the MIT Observatory sign or the Westford sign, you’ve gone too far. Likewise, if you are coming from Westford on Route 40 turn right just after the MIT sign. We will meet across the road from the transfer station near the end of CPB Drive.

Click on the route maps below for a full size view.

Stone Arch Bridge 1     Stone Arch Bridge 2

S tone Arch Bridge

From: http://members.bellatlantic.net/~edlisay/stone.htm

A recent walk along an abandoned railway in Westford, Massachusetts resulted in my rediscovery of what one historian called "the most impressive stone arch structure in the Merrimack Valley."

The few living souls that know that this thing exist simply refer to it as the "Stone Arch Bridge Over Stony Brook." Built around 1872 to carry trains from Nashua, New Hampshire to Concord, Massachusetts, the bridge last saw a train in 1925. Although the tracks were removed in the summer of 1926, much of the old right of way through Westford remains clearly visible.

The arch spans sixty five feet and is more than twenty five feet thick. Granite stones used in the bridge and its massive wing abutments were cut at a local quarry. The huge gray blocks were hauled to the site by twenty yoke of oxen.

Irish laborers spent months on this prodigious project, using little more than their hands to build this imposing structure. The construction of a keystone arch requires a temporary wooden structure be built to hold the stones in place until the keystone --the central wedge-shaped stone that locks all the parts together-- is put in place. No mortar or metal reinforcement was used in the construction.