Plantation Island and the German Flatts Canal of 1798


THE GUARD LOCK OF THE 1798 CANAL

Although the lift lock has long since been washed away or deeply buried by the action of the river, the guard lock at the west end of the canal has been archeologically re-discovered. It preserves for carefully controlled scientific study in the future the remains of the oldest intact canal lock in New York State.

An 18th century guard lockDuring the 1982 environmental impact study for NYSDOT, the State Museum team examined the area at the west end of the 1798 alignment intensively. We did not expect to find any evidence of the guard lock because of our experience at the comparatively undisturbed lift lock site at the east end of the canal, where nothing remained. In addition, the area around the guard lock had been heavily impacted by Erie Canal construction (1820s-1850s) and recent dredging (c 1950s). DOT had used the sub-grade area enclosed by the old Erie Canal berme and the modern Barge Canal berme as a dredging disposal basin and had cut a lagoon drain [90 KB] through the Erie Canal and along the old 1798 Guard Lock alignment.

Because the linear depression that ran on the 1798 canal trough was also apparently part of this 1950s lagoon drain, it was not believed that archeological investigations here would be productive. Since this area was outside the assigned study area, no excavations were planned during 1982.

The masonry first spotted by DECIt was several years later, in 1988-89, that John Page of the Utica Office of NYS Department of Environmental Conservation, while patrolling the DEC wildlife property to the east, noticed a line of exposed masonry in the general location of the guard lock and reported it to the State Museum. Although it seemed too insubstaintial to be a lock wall, being only about a foot wide, it was on the correct alignment and so archeological investigation was scheduled.


camera iconView field pictures from the western sector of Plantation Island and a key map for the sites there.

Over the course of the next several years, preliminary excavations by the State Museum revealed most of the intact south wall of the 1798 guard lock.This lock had a chamber estimated from documntary sources to be "an area of seventy-four feet by twelve in the clear." The guard lock excavations revealed intact masonry in one chamber wall extending over 70 feet in length and over 6 feet below ground. While this lock wall does not match the expected design for typical locks of the original Erie Canal, it does appear to have a gate recess at the east (inland) end of the chamber. Interestingly, one of the English canals where the masonry structure most resembles the German Flatts guard lock being exposed archeologically is the Oxford Canal, worked on by William Weston in 1786-90, just before he came to America to design locks, among them the ones at German Flatts.

Through a lead provided us by Charles Hadfield, British canal historian, a notebook of William Weston's, believed to contain some American lock drawings, was located at the British Institution of Civil Engineers. Nine pages were provided relevant to lock construction, of which only four pertained to American canal works.

Take a look at the pages from Weston's notebook, with an 1803 profile of the lift lock on the German Flatts Canal.

Miraculously, the three locks described on these four pages are the 1797 Mohawk River Lock at Rome, the "Guard Lock at the German Flats, 1798" [Hi Res Image = 220 KB] and "Lock at Flats - 12 foot lift." [Hi Res Image = 220 KB]. While no drawings accompany these accounts, the detailed listings of materials actually used during construction provide an avenue of architectural reconstruction unprecedented for works of this era.

The roster of timberwork used at the guard lock suggests a truly transitional technology, where the masonry was only one component of the total construction, to be integrated into a substantial timber sub- and super-structure that appears to rival wooden locks of the period. While it is impossible to determine precisely the application of these raw materials in the final lock construction, these data will be carefully integrated with ongoing archeological investigation to reveal, at the end, a comprehensive 3-dimensional image of this experimental engineering.

The excavated interior lock wallThe masonry in this lock is made up of relatively small, flat limestone slabs of variable thickness, some as thin as an inch, and rarely over 5 inches thick. (Click image at left for closer view - the exposed 1798 lock wall is seen to right of excavator.) This reflects the source at Little Falls, south of the river, and similarity to the laminated strata in the Thruway rock cuts previously mentioned. Ample mortar is used to bind this stone together, giving the resulting wall an appearance not unlike a typical early 19th century house foundation. Certainly it bears little similarity to the first locks on the Erie, nor is it very much similar to the larger, well formed blocks evident in early drawings and photographs of the 1803 rebuilt locks at Little Falls.

The plan of excavations - 1990sBut no matter how crude, this chamber wall, hopefully to be matched by its mate during future excavations, thus far hindered by deep spoil banks, represents the oldest intact canal lock in New York State. Although there were earlier locks built by the WILNC, namely those built at Little Falls in 1795 and at Rome in 1797, in all cases these were torn down and rebuilt in stone in 1803. This lock at German Flatts, originally built of stone in 1798, has stood unmodified to this day, the earliest surviving evidence of the evolution of canal lock engineering in New York, and perhaps in much of the Northeast. [Large format image of map at left = 90 KB.]


Some Views of the Excavations

View 1

This is a view of the exposed stonework as it was first found in the late 1980s (looking west).

View 2

This is a view of the exposed stonework during preliminary excavation and mapping looking east).

View 3

This is a view of the excavation of the lock gate recess at the east end of the lock.



This is a view of the completed excavation unit at the lock gate recess (above) showing the corner of the recess. (Note imprint of missing capstones in the mortar. Stones were probably recycled for use in the Erie Canal in the 1820s.)



NOTE: Any collecting, excavation, and all other types of archeological activity on state lands requires a Section 233 State Lands Permit.

 


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