Public Archaeology Laboratory (PAL) – March 2018
On behalf of National Grid, archaeologists from The Public Archaeology Laboratory, Inc. (PAL) monitored and recorded the demolition of the granite seawalls. The demolition work began in October 2015 and was completed in January 2016.
The historic data analysis, done in the summer and fall of 2017, confirmed that the granite seawalls were gravity-type structures composed of battered, dry-laid, split-faced granite blocks and stones, one-stone thick, with uneven or no coursing. The single stone vertical walls were reinforced with dense ballast composed of mixed-size cut stones and cobbles, reinforced with earth fill containing old timbers near the bottom of the wall. Some of the seawall capstones and upper granite blocks were anchored with 1-inch rounded wrought iron rods or pins for structural support.
The historic granite seawalls exemplify nineteenth-century stone seawall and wharf construction that required the highest quality granite and expert stone masonry cutting and fitting techniques. The granite would have been readily available and abundant in the local Cape Ann quarries around Gloucester.
On behalf of National Grid, architectural historians from PAL oversaw the reconstruction of the granite seawalls in the remediation project area of Solomon Jacobs Park and the National Grid building lot.
The new seawall reconstruction began in January 2016 and was completed in the late summer of 2017. The new granite seawalls were designed and built to be compatible with Gloucester Harbor’s historical character and to meet stringent engineering requirements. The front faces of the new walls are battered and gaps between the face and backing walls are filled with chink stones and gravel.
The granite used in the new seawalls was salvaged on site during the seawall demolition and supplemented as needed to meet the historical design requirements. The seawall reconstructions involved the placement of new wood deck railings. New granite block benches made from materials salvaged during the demolition work were also installed in Solomon Jacobs Park.
PAL’s oversight work also included the reconstruction of the granite seawall on the nearby Maritime Gloucester property. The remediation work required the removal of the top 4 feet of the wall, including the concrete cap and one course of granite blocks in front of the Maritime Gloucester boat house. A new timber deck walkway was added on top of the seawall, which was made to look like the original seawall. The reconstruction was done from February to April 2017.
On behalf of National Grid, PAL’s marine archaeologist from David S. Robinson Associates (DSRA) monitored, inspected, and recorded portions of the two historic marine railways as part of the harbor dredging operations.
Submerged portions of an inactive marine railway were exposed and removed from the harbor floor during the dredging operations. The inactive marine railway was the first and smaller of the two railways built in the Burnham Brothers Shipyard by the Crandall Dry Dock Company of East Boston. The railway was completed in 1849–1851 with an approximate length of 250 feet, and was used to repair vessels up to 500 tons until it was destroyed by fire in 1953. Following the fire, the shipyard owners abandoned the railway and left it to decay in place below the high water line.
The 2016–2017 archaeological monitoring work identified and recorded 50 individual railway elements, including wood rail sections, iron rail plates, wood bilge blocks, wood pier piles and a railway foundation pile, and wood cross-ties.
Underwater portions of a second marine railway that extends approximately 350 feet into the harbor from the Maritime Gloucester property were also recorded and documented. This second railway was built in 1853 for the Burnham Brothers Shipyard by the same Crandall Dry Dock Engineers of East Boston to service and repair vessels up to 1,000 tons, and is the oldest continuously operating marine railway in the country. Maritime Gloucester now uses the railway to repair wooden schooners and enhance its maritime educational programs.
DSRA reviewed underwater video of the submerged portions of the marine railway that were exposed in the harbor floor during the remediation project’s hand-dredging operations. Identified remains consist of the back-haul sheave assembly and its wood foundation, diagonal cross-bracing between the rails, and wood shims and wood caps between foundation piles and cross-ties where they connected to the undersides of the rails.
To learn more about the historic and archaeological resources studied as part of the Former Gloucester MGP Remediation Project, see
Public Archaeology Laboratory (PAL) – December 2016
The Public Archaeology Laboratory, Inc. (PAL) is providing cultural resources services in support of the Remediation Project. PAL’s work at the site was ongoing throughout 2016, and the following narrative and photographs provide a summary of their work completed to date to document the seawall removal, excavation, and reconstruction; and progress on the marine railways documentation and recordation.
Project contractors removed the historic granite wharf and adjacent soils in Solomon Jacobs Park during the fall of 2015 and winter of 2016. Excavations uncovered several components relating to historical gas manufacturing activities at the site. These consisted of large concrete footings, remnants of brick walls and foundations, and piping.
Below these more recent archaeological remains, the lower soils behind the wharf were composed of fill. Previous occupants of the site had dumped this material into the harbor as they “wharfed out” their property to create more usable land. Mixed into this fill were large amounts of granite rubble salvaged from Cape Anne’s many quarries, as well as isolated cultural artifacts such as shoes and broken bottles.
The Solomon Jacobs Park seawall was rebuilt in the winter and spring of 2016. The Project team designed and built a new wall that would be compatible with Gloucester Harbor’s historical character and meet stringent engineering requirements.
Project contractors completed pre-dredge debris removal in the near shore areas of the historic marine railway structures in September 2016. The debris removal was performed by commercial divers assisted by a barge-based large machine-excavator that was used to lift items rigged by the divers out of the water and into a hopper barge. PAL’s marine archaeologist from DSRA inspected and recorded historic marine railway elements and other debris that were found by the divers lying on or extending above the surface of the inner harbor floor. Marine railway elements include pieces of wood railway timbers and iron. Included among the recovered wood elements are intact and fragmentary pieces of the inactive marine railway’s rails, cross-ties, and chocking-timber components of the inactive marine railway’s cradle. The iron pieces are fragments and intact sections of the inactive marine railway’s iron strapping with fasteners that were formerly attached to the top of the railway’s wooden rails.
Dredging work to remove contaminated sediments and portions of the inactive marine railway extending to the 2004 Gloucester Harbor Commissioner’s Line began in November 2016. PAL’s marine archaeologist will continue with the field monitoring and recordation work for any components of the historic marine railways that are encountered and removed from the harbor floor during dredging.