The Plattsburgh breakwater is an historic structure, located in Plattsburgh Bay, that protects the harbor of the city of Plattsburgh (Figure 1). The breakwater is 1,550 feet in length, and consists primarily of a series of stone-filled timber cribs, or caissons, capped with large granite capstones. Similar construction techniques are found in the breakwater that protects the harbor of the city of Burlington, Vermont (Cousins 2000; Lydecker and Cousins 2001, 2002). Authorization to construct the initial 850 feet of the breakwater was given by Congress in 1836, and construction began in 1838. It was constructed in three phases: 1) 850 feet during the 1840s; 2) 400 feet during the 1870s; and 3) 300 feet during the 1890s.Numerous repairs have been conducted in the twentieth century, including replacing capstones and armor stones (1893, 1910, 1940), adding a rubble mound to the lake face (1913-1914), and adding rubble mounds to the ends (1950). The last repairs occurred in 1971, when new stonework was added to the north end. The breakwater has now failed along much of its length, and is no longer capable of performing its function of protecting Plattsburgh Harbor.

The New York District U.S. Army Corps of Engineers has proposed repairs to the breakwater in order to make it functional again. As part of this project, team archaeologists from Panamerican Consultants, Inc, of Memphis, Tennessee, working in conjunction with the Corps of Engineers and Northern Ecological Associates of Canton, New York, recorded 1200 feet of the historic structure of the breakwater. They examined the entire harbor face of the structure, and found several different construction styles which coincide with the periods of construction mentioned above. Data gathered included video, site descriptions, and annotated drawings. Underwater investigations focused primarily on obtaining information regarding construction techniques, as well as historic damage and repairs. It was discovered that three types of timber caisson, coinciding with the three phases of construction, were used in the structure. These timber caissons utilized two different types of timber frame joints in their construction. It was concluded that the newest section of the breakwater, constructed between 1890 and 1896, was in the best condition with respect to integrity.

Figure 1. Project area location map (source: U.S.G.S. Plattsburgh, New York-Vermont 7.5' quadrangle).

 

 

History of the Plattsburgh Breakwater

The opening of the 64-mile Champlain Canal in 1823 provided a direct water route between Lake Champlain and the Hudson River. The canal spurred the economic development of the Champlain Valley region, expanding the domestic market for the region's extractive industries such as timber cutting, stone quarrying, and iron mining. This resulted in greatly increased boat traffic on the lake. In the 1830s, the U.S. government was called into action to expand and protect navigation and commerce on Lake Champlain, and improving the harbor in Plattsburgh, New York was part of the Federal government's large-scale undertaking.

Eventually, the U.S. government would construct five federal breakwaters on Lake Champlain: Plattsburgh; Burlington; Swanton, Vermont; Rouses Point, New York; and Gordon Landing at Grand Isle, Vermont. The Plattsburgh, Burlington and Swanton breakwaters were built of stone-filled timber-cribs. Because the harbors in Rouses Point and Gordon Landing were located in shallower water, the structures built there were stone mound. In 1836, construction began on breakwaters in Plattsburgh and Burlington, but Port Kent never received its protected harbor, as it was stricken from the appropriations bill.

Figure 2. Diagram of breakwater showing three phases of construction.

The Plattsburgh breakwater, which ultimately extended to its present length of 1,565 feet, was constructed in three stages (Figure 2). The original project was adopted under an act of Congress on July 4, 1836, authorizing the construction of a breakwater and pier to protect the wharves from southerly and easterly storms. In 1870, an act of Congress authorized the construction of an extension of 400 feet in a northerly direction, so that by 1874 the breakwater extended to 1,250 feet. The third stage, authorized by Congress in 1890, provided for further construction of 300 feet in a northerly direction and for the replacement of the timber superstructure with stone. This final enlargement was completed on January 17, 1893 (USACE 1893). Beacon lights were placed at both the north and south ends. The total costs for construction of the Plattsburgh breakwater to a length of 1,565 feet amounted to $185,440.76 (USACE 1904).

After the completion of the three stages of construction, the U.S. Congress authorized funding for improvements in the Plattsburgh harbor. In 1916, appropriations were allocated for construction of a rubble mound to prevent the destruction of the lake face of the breakwater (USACE 1916). After this date, the Federal government several times authorized funds for maintenance, and repairs were carried out in 1940, 1950, and 1971.

Phase 1 Construction: 1836-1844

Brigade Major and Topographical Engineer Hartman Bache, who had surveyed the harbors of Plattsburgh, Burlington, and Port Kent on Lake Champlain for the Secretary of War in 1834, laid out in his report the rationale for improving Plattsburgh Harbor. He said, basically, that Plattsburgh harbor is important both as a place of refuge for passing vessels during rough weather, as well as an important location for the purposes of trade, and this value justified the expense of improvement. He also noted that the construction of a dam on the Saranac River and deposits from mills had silted in the harbor and reduced its usefulness. He proposed the construction of a breakwater as a solution. Because of its durability, he proposed using white pine for the structure from one foot below the lowest water level, and squared timber for the facing. All timber, whether it was the more expensive white pine or the round and squared hemlock, should be not less than one foot. He also suggested that, should it be necessary to create a more permanent structure, the timber superstructure be replaced by stone.

On July 4, 1836 Congress appropriated $10,000 for the Plattsburgh breakwater construction, and in September the U.S. agent for work and expenditure solicited construction bids in the newspaper (Plattsburgh Republican, Sept. 10, 1836).

By 1838, the Chief Topographical Engineer reported to Congress that "about 620 feet of crib-work had been put into place, finished to the high water mark, and filled with stone. As soon as the ice has formed of sufficient strength, it is contemplated to finish that part of the work of those piers which lies above the high-water mark" (Report of the Chief Topographical Engineer November 26, 1838 in Congress 1838).

In 1842, the Corps of Engineers reported that: "This work has been built up to within one foot of the required height, for a length of 500 feet, and gives a very important protection to vessels approaching to, and being at the wharves..." . The Plattsburgh breakwater extended to 696 feet in 1843, and by 1844, with the addition of 160 feet, the oldest section had been completed and reached to 846 feet (USACE 1844). In the 1860s there was mention of an additional 50 feet, and on the harbor map from 1869 a length of 860 feet is printed (Figure 3).

Phase 2 Construction: 1870-1874

In the late 1860s, surveys of Plattsburgh Harbor conducted by the U.S. Army Corps of Engineers indicated the need for further improvements. Brevet Brigadier General C.B. Reese, U.S. Army Captain of Engineers, surveyed the harbor in November 1866 and mentioned the type of improvements he would propose: "The breakwater is 854 feet in length, including 50 feet added to the south end some two years ago. The entire wood-work of the old part above extreme low water mark is badly rotted and needs to be replaced with sound timber. The stone ballast of this part has settled away from two to three feet, requiring a considerable amount of stone to carry it up to the proper height. The new portion, or the fifty feet on the south end, needs no repair" (USACE 1867).

Figure 3. F.W. Beers 1869 atlas of Clinton County, New York; note breakwater in lower middle (courtesy of the U.S. Army Corps of Engineers, Albany Field Office).

In 1870 the U.S. Congress appropriated funds for an extension of 400 feet to the Plattsburgh breakwater, and bids for crib completion and sinking and construction of the superstructure were advertised on September 23, 1870. Proposals were received from contractors E.R. Seward and Luther Whitney (USACE 1870).

By the beginning of 1871 one crib 94 feet long and 25 feet wide had been sunk and filled with stone, and another advertisement secured three more bids. This time contractors Jonathan P. Hagar, Samuel G. Hart, and Luther Whitney submitted bids, and although Whitney's proposals were the lowest, the report does not indicate who received the contract. Work on the superstructure was started in September 1871, and by 1872 an extension of 150 feet had been completed (USACE 1871, 1872). James D. Leary of Brooklyn, New York was awarded a contract on September 28, 1872 to construct 100 feet, and on June 25, 1873 Luther Whitney of Keeseville, Essex County, New York was given a contract to extend 56 feet in a northeasterly direction (USACE 1873).

By the end of 1874 the breakwater extended to 1,250 feet, and the government had spent an additional $49,019.51 to build this middle section (USACE 1878).

Phase 3 Construction: 1890-1893

Major M.B. Adams explained in a letter written to the Chief of Engineers on November 8, 1888 his rationale for proposing an extension of the breakwater 300 feet on the north end: "There is considerable opening between the north end of the breakwater at Plattsburgh and Cumberland Head, for all the more northerly docks at the harbor, such that they are more or less exposed to wave action when the wind is blowing from an east by south to a southeast course, and with reaches that vary from five to eight miles; and as the shipping facilities are more likely to be extended toward and around the mouth of the Saranac River, or northward, than in the other direction, this exposure is likely to become more and more serious" (USACE 1889).

He likened the construction work to the "last approved project for Burlington breakwater," and in September 1890 Congress appropriated $32,500 for the extension. In one contract, the old timber crib superstructure was replaced with a rubblestone core and large facing stones, and an extension of 300 feet was built, finished on top in the same manner (USACE 1891).

On January 17, 1893 the Plattsburgh breakwater, with its rubble foundation, cribs to one foot below low water, and large paving-stone superstructure, extended to 1,565 feet. With the completion of this extension, the construction phases of the breakwater were finished.

Repairs and Maintenance

After 1893 there were a number of important repairs made to the structure as well as periodic dredging projects. In 1903 Daly and Hannan Dredging Company of Ogdensburg, New York received a contract to dredge out sawdust, sand, mud, clay and boulders from the harbor, and in 1904 the timber crib pierhead at the south end of the breakwater was rebuilt (USACE 1904). Congress authorized in 1910 further funds for repairing the breakwater. The appropriation of $25,500 was used for dredging to the depth of nine feet at low lake level the shoal between the breakwater and the wharves, redredging the channel in front of the wharves, and repairing the breakwater by rebuilding the superstructure of the timber piers with stone.

Wooden superstructures at the ends of the breakwater were replaced with concrete piers under an informal agreement made with James E. Cashman (USACE 1913). Proposals for constructing a rubble mound on the lake face of the breakwater were opened in July 1912, but the only bid received was rejected because of its high price. An emergency contract for placing a rubble mound was made in December 1912, and material was placed through the ice during February and March, 1913 and 1914 (USACE 1913). Figures 4-6 are illustrations of the Plattsburgh breakwater circa 1913.

Figure 4. Photograph of general view of Plattsburgh breakwater, circa 1913 (courtesy of the U.S. Army Corps of Engineers, Albany Field Office, photograph #478).

 

Figure 5. Photograph of Plattsburgh breakwater looking north, circa 1913 (courtesy of the U.S. Army Corps of Engineers, Albany Field Office, photograph #479).

Figure 6. Photograph of north pier of Plattsburgh breakwater looking south, circa 1913 (courtesy of the U.S. Army Corps of Engineers, Albany Field Office, photograph #472)

In December 1914, James Cashman completed the construction of a protecting rubble mound along the lake face of the breakwater for a distance of 700 feet from the north end southward (USACE 1915). Again in 1915, there was a proposal to build a rubble mound on the southern section from the toe of the present superstructure lakeward, and James Cashman received the contract for that work in June 1917. No work was done on this project in 1918 or 1919 because of World War l, but in 1920 Cashman completed the contract.

In 1931, the Corps of Engineers issued the last complete annual report detailing improvements made to the Plattsburgh breakwater. Up to June 30, 1931 total expenditures amounted to $235,006.60, and from 1910 to 1931 the cost of maintenance had been $36,591.47. The report also summarized the effect of the improvement: "The water-borne commerce of this port during gales from the east and southeast is practically dependent for its existence upon the protection afforded by the breakwater, which also gives to through lake traffic a harbor of refuge during storms. This through traffic consists principally of towed canal boats, numbering about 75 yearly. The improvement also permits the use of lake steamers, which ply daily between this port and Burlington, Vermont during the navigation season" (USACE 1931).

In 1940 a major breakwater rehabilitation project was undertaken. Repairs were made to all three sections of the breakwater: the south arm, 854 feet in length; the middle arm, 414 feet long; and the north arm, 297 feet long. The work consisted of tearing out old capstones and replacing them with new core stone.

In 1950 repairs were made to improve lights at each end of the breakwater as well as dredging the harbor behind the breakwater, as well as the placemnt of 3200 tons of stone at each end of the breakwater (Figure 7). The same thing was done to the north end in 1971.

Figure 7. Survey of north light, November-December 1944 (drawing by Adam Loven).

Since 1971 there have been no repairs or maintenance carried out on the breakwater in Plattsburgh. However, in 1972 and 1977 soundings were made in the harbor, and in 1977 the north light was removed. In 1984 the breakwater was surveyed but although improvements have been considered to be necessary and even urgent by city officials, no maintenance projects have been funded. In June 2001 the breakwater was so low that it could not be seen from the harbor. Keith Herkalo, Plattsburgh city clerk, regards the breakwater as "a hazard to navigation". The breakwater, which was built in the nineteenth century to protect the harbor in Plattsburgh Bay against wind and sea, does not serve its original function, and on the contrary, obstructs safe use of the harbor (personal interview, June 15, 2001).

During this investigation, the entire harbor side of the breakwater was examined. Five areas, totaling roughly 1200 of the 1500 feet of the structure, were recorded in detail (Figure 8). The investigators focused on those features that were diagnostic with regard to the construction history of the breakwater. While the investigators wanted to obtain detailed information on each caisson, including length and construction type, this was not possible due to the extremely deteriorated condition of the breakwater. A total of seven intact caissons were examined; these were divided into three types based on timber and joint types used in the construction. It was discovered that the locations of the types coincided with the three phases of construction as detailed in the historical background of this report. This was to be expected, as groups of caissons constructed at the same time would likely be constructed by the same contractor and in the same style. For the purposes of this investigation, each construction phase section was given a number designation, with the oldest being Section 1 and the newest Section 3 (Figure 9).

Figure 8. Map of breakwater showing locations of areas investigated.

 

Figure 9. Map of breakwater showing sections examined.

 

Construction Techniques

Three basic variations of timber crib construction were noted during the investigation, including two solid and one open crib type (the Burlington Breakwater website contains information on basic timber-crib construction). Caissons ranged in length from 40 feet to 100 feet, with most being 50 feet in length. Historical documents indicate they were constructed of hemlock below water and pine above water. Each caisson was generally placed directly next to the adjacent caisson, with anywhere from a few inches to several feet of separation. There appeared to be no visible means of attachment between caissons.

In carpentry terms, the place where two pieces of wood fit together is known as a joint. The joints documented in the breakwater structure are some of the most common and simple joints used by carpenters and cabinet makers. Joints are chosen based on a variety of factors including type of wood and intended use of the final product, as well as expediency of construction. The latter choice is expected to be the case in the construction of the breakwater.

Two types of joints were used to fasten the timbers. Both were variations of a saddle notch. Sections 1 and 2 of the breakwater, coinciding with caissons Type 1 and Type 2, used a saddle notch, while a housed saddle notch was used in Section 3 (caisson Type 3) of the structure.

Saddle Notch

This joint (Figures 10 and 11) is often referred to as a Lincoln Log joint, or log cabin joint. It is used to join two timbers at right angles to each other, and consists of two saddle shaped or squared notches in each joined timber, one on top and one on the bottom of each timber. It is a simple, yet astonishingly strong joint.

Figure 10. Drawing of saddle notch joint.

 

Figure 11. Photograph of saddle notch joint with square timbers.

 

Housed Saddle Notch

This joint (Figures 12 and 13) is one of the types documented by Panamerican in 2000 (Lydecker and Cousins 2001) in an investigation of the Burlington breakwater. It consists of one saddle-shaped or squared notch, alternating top and bottom, in successive timbers so that when fit together the notches form a square hole. The header, at right angles to the stretcher, is not notched, but fits entirely into this square hole. The strength of the joint is provided entirely by a one inch iron pin driven through the joint. This is not a terribly strong joint, and significant deterioration has been noted in sections employing this joint. This joint was found exclusively in Type 3 caissons.

Figure 12. Drawing of a housed saddle notch.

 

Figure 13. Photograph of a housed saddle notch.

End Half Lap

This joint (Figures 14 and 15) is also known as a scarf halving joint, but the former term is used to avoid confusion with a scarph joint. The end half lap joint is used to join timber end to end. The length of the lap, or wood removed, is generally equal to the width of the timber, although in the breakwater structure the lap seems to have been made longer in many cases. The reason for this is unknown. The joint requires the support of the timbers above and below to have any strength. No means of fastening this joint was observed.

Figure 14. Drawing of end half lap.

 

Figure 15. Photograph of end half lap.

 

Butt Joint

A butt joint (Figures 16 and 17) is the most basic, easiest to make, and has the least strength of any joint. No cutting or removing of timber is done with a butt joint. The timbers are simply glued or fastened together. In the case of its use in the breakwater, the ends of the timbers are simply placed next to each other and held in place by the timbers above and below. No visible means of fastening was observed for this joint. These joints occurred either staggered, where the joints occur in the same place in the caisson and at regular intervals, or randomly, where they occur in no apparent pattern.

Figure 16. Drawing of butt joint.

 

Figure 17. Photograph of butt joint with round timbers.

 

Caisson Types

Caissons were divided into types based on construction techniques. The main factors considered were corner and interior joints, timber size, and stretcher joint type. Three caisson types were identified in the breakwater structure (Table 1).

Type 1

This type, encountered in Section 1, is the oldest in the breakwater structure and corresponds with Phase I construction as detailed in the Background Research chapter. Individual caissons that were documented measured 50 feet in length; a width measurement of 50 feet at the base and 45 feet at the top was taken on the southernmost caisson in the section. It is likely that there were caissons of 100 feet in length, as this is mentioned in the historical records, but none were documented as much of Section 1 was heavily deteriorated. In many places the capstones and rock spillage from inside the structure had completely obscured the wooden structure. Timbers used in construction were both round and square. Round timbers consisted basically of raw logs with the branches and bark stripped off, and varied in diameter from 12 to 18 inches. Square timbers varied from nine to 12 inches square, although this variation is likely the result of erosion. It is safe to say that the timbers were 12 x 12 initially. All joints were of a saddle notch type, and were fastened using one inch diameter iron pins.

Figure18. Drawing of Type 1 caisson.

Figure 19. Cross section of Type 1 caisson.

 

Type 2

This type, encountered in Section 2, is the second oldest in the breakwater structure and corresponds with Phase II construction as detailed in the Background Research chapter. Individual caissons that were documented measured 50 feet in length; a width measurement was not taken as the lake face is covered with stone. It is likely that there were caissons of 100 feet in length, as this is mentioned in the historical records, but none were documented as much of Section 2 was heavily deteriorated. In many places the capstones and rock spillage from inside the structure had completely obscured the wooden structure. Timbers used in construction were square, and varied from nine to 12 inches square, although this variation is likely the result of erosion. It is safe to say that the timbers were 12 x 12 initially. All joints were of a saddle notch type, and were fastened using one inch diameter iron pins (Figure 20).

Figure 20. Drawing of Type 2 caisson.

 

Type 3

This type, encountered in Section 3, is the newest in the breakwater structure and corresponds with Phase III construction as detailed in the Background Research chapter. It is also the best preserved of the breakwater sections. Individual caissons that were documented measured 50 feet in length; a width measurement was not taken as the lake face is covered with stone. Timbers used in construction were square, and varied from nine to 12 inches square, although this variation is likely the result of erosion; it is safe to say that the timbers were 12 x 12 initially. All joints were of a housed saddle notch type, and were fastened using one inch diameter iron pins (Figure 21).

Figure 21. Drawing of Type 3 caisson.

 

 

The New York District U.S. Army Corps of Engineers has proposed repairs to the breakwater in order to make it functional again. As part of this project, team archaeologists from Panamerican Consultants, Inc, of Memphis, Tennessee, working in conjunction with the Corps of Engineers and Northern Ecological Associates of Canton, New York, recorded 1200 feet of the historic structure of the breakwater. They examined the entire harbor face of the structure, and found several different construction styles which coincide with the periods of construction mentioned above. Data gathered included video, site descriptions, and annotated drawings. Underwater investigations focused primarily on obtaining information regarding construction techniques, as well as historic damage and repairs. It was discovered that three types of timber caisson, coinciding with the three phases of construction, were used in the structure. These timber caissons utilized two different types of timber frame joints in their construction. It was concluded that the newest section of the breakwater, constructed between 1890 and 1896, was in the best condition with respect to integrity.