Lock 18 of Enlarged Erie Canal
Also known as: Double Lock
Why it's listed
Lock 18 of the Enlarged Erie Canal, known as the "Double Lock," sits in Cohoes, Albany County, west of North Mohawk Street and near Reservoir Street. Built between 1837 and 1842, it is made of cut stone laid in a random ashlar pattern, with blocks averaging about three feet long, two feet high and one and one-half feet wide. The wooden gates have disappeared and the lock now holds no water, leaving only the masonry. It was part of an effort to cut the number of locks between Albany and Schenectady, which made travel faster and easier on one of the canal's hardest sections. Backers of the Enlarged Canal expected that doubling the locks and enlarging both locks and channel would strengthen the state's economy and reduce the threat from railways. The stone was generally Amsterdam stone. Engineer I Holmes Hutchinson prepared the lock plans used in construction. The lock is valued as a fine example of canal-era masonry.
Significance in brief: The lock was part of a scheme to reduce the number of locks between Albany and Schenectady, easing travel on one of the canal's most difficult stretches. Promoters of the Enlarged Canal believed larger, doubled locks would strengthen New York's economy and blunt competition from railways. It is described as a fine specimen of canal-era masonry work.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · National Archives catalog entry. NRHP reference 71000526, listed February 18, 1971. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence medium).
Key facts
| Address | W of 252 N. Mohawk St., E of Reservoir St. near Manor Ave., Cohoes |
|---|---|
| County | Albany County |
| Listed | February 18, 1971 |
| Reference number | 71000526 |
| Resource type | Structure |
| Period of significance | 1837 - 1842 |
| Architect / builder | Plans for the locks by John B. Jervis is not stated; the form names I Holmes Hutchinson (1794-1865), civil engineer, whose plans for the Enlarged Canal locks were used for construction |
| Areas of significance | Engineering, Transportation |
| Level of significance | National |
| Status (as stated in the nomination) | Condition listed as deteriorated and altered; only the masonry construction remains, the wooden gates are gone, and the lock contains no water. Present use is given as ruins. |
| Acreage | 1 |
| Coordinates | 42.78553, -73.71170 (NPS GIS) |
What listing means for this property
National Register listing is honorary: it recognises significance and does not restrict what a private owner may do without federal money or permits. It unlocks the 20% federal rehabilitation tax credit for income-producing buildings, state credits in many states, and Section 106 review when federal agencies are involved. See what listing means in practice.
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.
Sources and further reading
- National Park Service, National Register of Historic Places database (snapshot May 2026), reference 71000526.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q6665209
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.