Bridge Repairs Bath Covered Bridge, Bath New Hampshire
In 1852, the White Mountain Railroad was graded along the west bank of Ammonoosuc River underneath Bath Bridge. Rails were laid, and service began in 1853. Apparently the bridge required no structural modifications at the time, but since steam engines passed closely under it for about a century, it is fortunate that it never caught fire. At some unknown time, the railroad installed sheet metal under the bridge in the area of the tracks to prevent sparks from lodging.
The addition of a third pier later divided the long west span of Bath Bridge into two, making it a four-span bridge. There is no evidence documenting when this was done, but it was probably during the nineteenth century since the new pier is dry-laid stone and difficult to distinguish from the two originals. Had the pier been added when the laminated arches were installed in 1918-19, it would surely have been of concrete.
By a 1913 act of the New Hampshire legislature, bridges were to be made safe for 10-ton loads after April 1, 1915. The law created a tremendous burden for small towns, and compliance was slow. Bath Bridge at the time was posted for 2 tons. Concerned, the town asked famed bridge engineer John W. Storrs of Concord for an opinion. He said that the bridge had probably carried more than 2 tons but recommended that the posted load not be exceeded.
At a 1918 town meeting, Bath voted funds "for extraordinary repairs on Bath bridge." It was suggested to raise $1,000 by taxation and finance the rest. Mr. C.C. Battey, recommended by engineer Storrs, presented an estimate covering various options. Later, when the work was done, he inspected it, but it is unclear how much he did himself, if any.
By 1919, the bridge straightening project had cost $7,076.61. This was more than foreseen, but more work had been required. Among other things, the railroad decided that the bridge should be raised 2' higher over the tracks and paid for the actual raising, but various expenses such as regrading the road had to be covered by the town.
Work got underway in 1918 when Cyrus Batchelder repaired a flood-damaged pier and cut skewbacks and cut skewbacks into the old piers and abutments to receive laminated arches. The stonework also received concrete caps so that the bridge could be raised. Some 70,000 board feet of lumber of all kinds went into the project. The arch planks appear to have been hemlock. Much red and yellow pine was used, probably for the floor system.
Twelve or thirteen leaf laminated arches went into the easterly three spans, but the west span, over the railroad tracks, did not get a new arch. At some point, wooden horses were added to either side of the tracks; these may have been part of the same project in lieu of arches. The new arches were connected to needle beams under the lower chords of the truss by means of hanger rods on spacing varying from 8'-0" to 8'-6". The new arches and needle beams relieved some of the load from the trusses, but there is no direct connection to the floor system, as is usually done.
Photographs dating as late as ca. 1950 show the west portal of Bath Bridge with a semielliptical arched entry, housed in narrow clapboards, similar to portals found on Peter Paddleford's bridges. Soon thereafter the entry was squared off higher to allow more clearance, and the older configuration has never been restored. The east portal was so modified decades earlier.
By 1987, Bath Bridge was in need of major repairs, and the job went to Milton S. Graton of Ashland, New Hampshire, one of the premier bridge wrights of the twentieth century. There was a low interior boarding like a wainscot, which Graton removed. He found many posts badly gnawed, and several were chewed all the way through. Local legend stated that residents had once used the bridge as a stable to tie up their horses while uphill at the village church or at saloons, and the restless horses had chewed the posts. This practice may have been very old, for the 1834 town meeting entrusted the agent who enforced the speed limit with keeping the bridge clear from "horses or cattle or anything else which shall have a tendency to injure the people who may cross." Graton's preferred practice was to leave original members in place, sistering new ones alongside to preserve the historic fabric.
The interior wainscot was perhaps intended to prevent future horse damage, but this danger was long past and Graton did not replace it. Later the town reinstalled it, although this makes it impossible to inspect and clean around the lower chords. Covered bridges always collect dust, which, by retaining moisture, can cause rot. Old town records throughout New England show small expenditures for ongoing maintenance, including cleaning and sweeping, but in recent decades most towns have neglected this important detail.
Graton completed restoration in early 1988. Other work included reinforcing the arch ends where they are tied to the truss, and reroofing the bridge. Much rot had to be repaired over the former railroad tracks where the spark-arresting layer of sheet metal trapped moisture.