The Soo Locks (sometimes spelled Sault Locks but pronounced "soo") are a set of parallel
locks
Lock(s) may refer to:
Common meanings
*Lock and key, a mechanical device used to secure items of importance
*Lock (water navigation), a device for boats to transit between different levels of water, as in a canal
Arts and entertainment
* ''Lock ...
, operated and maintained by the
, Detroit District, that enable
ship
A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished ...
s to travel between
Lake Superior
Lake Superior in central North America is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. and the third-largest by volume, holding 10% of the world's surface fresh wa ...
and the lower
Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lak ...
. They are located on the
St. Marys River between Lake Superior and
Lake Huron, between the
Upper Peninsula
The Upper Peninsula of Michigan – also known as Upper Michigan or colloquially the U.P. – is the northern and more elevated of the two major landmasses that make up the U.S. state of Michigan; it is separated from the Lower Peninsula by ...
of the
U.S. state
In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...
of
Michigan
Michigan () is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the List of U.S. states and ...
and the
Canadian province of
Ontario
Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...
. They bypass the rapids of the river, where the water falls . The locks pass an average of 10,000 ships per year, despite being closed during the winter from January through March, when ice shuts down shipping on the Great Lakes. The winter closure period is used to inspect and maintain the locks.
The locks share a name (usually shortened and anglicized as ''Soo'') with the two cities named Sault Ste. Marie,
in Ontario and
in Michigan, located on either side of the St. Marys River. The
Sault Ste. Marie International Bridge
The Sault Ste. Marie International Bridge spans the St. Marys River between the United States and Canada connecting the twin cities of Sault Ste. Marie, Michigan and Sault Ste. Marie, Ontario. The bridge is operated by the International Bridg ...
between the United States and Canada permits vehicular traffic to pass over the locks. A railroad bridge crosses the St. Marys River just upstream of the highway bridge.
The first locks were opened in 1855. Along with the
Erie Canal
The Erie Canal is a historic canal in upstate New York that runs east-west between the Hudson River and Lake Erie. Completed in 1825, the canal was the first navigable waterway connecting the Atlantic Ocean to the Great Lakes, vastly reducing t ...
, constructed in 1824 in central New York State, they were amongst the great infrastructure engineering projects of the antebellum United States. The Soo Locks were designated a
National Historic Landmark
A National Historic Landmark (NHL) is a building, district, object, site, or structure that is officially recognized by the United States government for its outstanding historical significance. Only some 2,500 (~3%) of over 90,000 places listed ...
in 1966.
During World War II, the Soo Locks and the St. Marys River waterway were heavily guarded by U.S. and Canadian forces coordinated by the
U.S. Army
The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cl ...
's
Central Defense Command
Central Defense Command (CDC) was a command formation of the United States Army during World War II. The CDC was established on 17 March 1941, responsible for coordinating the defense of the Midwest region of the United States. A second major res ...
. A one-way German air attack on the locks by forces based in Norway was thought to be possible.
United States locks
The U.S. locks form part of a canal formally named the St. Marys Falls Canal. The entire canal, including the locks, is owned and maintained by the United States Army Corps of Engineers, which provides free passage. The first iteration of the U.S. Soo Locks was completed in May 1855; it was operated by the state of Michigan until transferred to the U.S. Army in 1881. The first federal lock, the Weitzel Lock, was built in 1881 and was replaced by the MacArthur Lock in 1943. The configuration consists of two parallel lock chambers, each running east to west. Starting at the Michigan shoreline and moving north toward Ontario, these are:
*The MacArthur Lock, built in 1943. It is long, wide, and deep.
This is large enough to handle ocean-going vessels ("salties") that must also pass through the smaller locks in the
Welland Canal
The Welland Canal is a ship canal in Ontario, Canada, connecting Lake Ontario and Lake Erie. It forms a key section of the St. Lawrence Seaway and Great Lakes Waterway. Traversing the Niagara Peninsula from Port Weller in St. Catharines ...
. The first vessel through was the
SS ''Carl D. Bradley''.
*The Poe Lock, built in 1896. The first vessel to pass through was the U.S. Army Corps of Engineers tug USS ''Hancock''. The original Poe Lock was engineered by
Orlando Poe and, at long and wide, was the largest in the world when completed in 1896.
The lock was re-built in 1968 to accommodate larger ships, after the
Saint Lawrence Seaway
The St. Lawrence Seaway (french: la Voie Maritime du Saint-Laurent) is a system of locks, canals, and channels in Canada and the United States that permits oceangoing vessels to travel from the Atlantic Ocean to the Great Lakes of North Ameri ...
opened and made passage of such ships possible to the Great Lakes. It is now long, wide, and deep.
It can take ships carrying of cargo. The Poe is the only lock that can handle the large
lake freighter
Lake freighters, or lakers, are bulk carrier vessels that operate on the Great Lakes of North America. These vessels are traditionally called boats, although classified as ships.
Since the late 19th century, lakers have carried bulk cargoes of ma ...
s used on the upper lakes. The first passage after the rebuild was by the ''Phillip R. Clarke'' in 1969.
A new lock is under construction and is slated to be completed by 2030. Groundbreaking for the new lock project was held on June 30, 2009. The lock will be equal in size to the Poe Lock and will provide much needed additional capacity for the large lake freighters.
The new lock replaces two locks (Davis Lock and Sabin Lock) which were obsolete and used infrequently. In May 2020, construction on Phase One of the replacement of the Sabin Lock was started.
North of the new lock is an additional channel with a small hydroelectric plant, which provides electricity for the lock complex.
Engineers Day
The U.S. Army Corps of Engineers, Detroit District, operates the Soo Locks Visitors Center and viewing deck for the public.
On the last Friday of every June, the public is allowed to go behind the security fence and cross the lock gates of the U.S. Soo Locks for the annual Engineers Day Open House.
During this event, visitors are able to get close enough to touch ships passing through the two regularly operating locks. Other than on that day, because the locks are United States Federal property under command of the U.S. Army Corps of Engineers, unauthorized personnel and civilians are restricted from the locks under threat of fines or imprisonment for trespassing.
Canadian lock
A single small lock is operated on the Canadian side of the Soo. Opened in 1895, it was rebuilt in 1987, and is long, wide and deep.
The Canadian lock is used for recreational and tour boats; major shipping traffic uses the U.S. locks.
Gallery
File:Soo Locks 19th Century.jpg, The first Soo Locks in the 19th century
File:Anchor Line Steamer in the Locks (NBY 9947).jpg, Anchor Line steamer in the Soo Locks, ca. 1900s
File:PoeLock whaleback MHGL00371f.jpg, A whaleback
]
A whaleback was a type of cargo steamship of unusual design, with a hull that continuously curved above the waterline from vertical to horizontal. When fully loaded, only the rounded portion of the hull (the "whaleback" proper) could be seen a ...
traverses the Poe Lock, ca. 1910
File:Sault canal NHS adjusted.jpg, Canadian Lock at Sault Ste. Marie, Ontario
File:Poe Lock - 2014.jpg, The last ship of the 2013 season passes through the Poe Lock
File:USCGC Mackinaw passes through Soo Locks 130314-G-ZZ999-001.jpg, USCGC ''Mackinaw'' passes through Soo Locks
References
*33 CFR 207.440
*33 CFR 207.441
Further reading
*
External links
Aerial viewsSoo Locks homepageU.S. Army Corps of Engineers Soo Locks page
Web Cameraview of the American locks NOTE: This Connection is Untrusted
Animation of how the Soo Locks workYouTube videoHD video of a ship passing through the MacArthur Lock
{{Authority control
Canals in Michigan
Locks of the United States
Locks on the National Register of Historic Places
Great Lakes Waterway
Ship canals
St. Marys River (Michigan–Ontario)
Buildings and structures in Sault Ste. Marie, Michigan
Michigan State Historic Sites
National Historic Landmarks in Michigan
Canals on the National Register of Historic Places in Michigan
Transportation in Chippewa County, Michigan
National Register of Historic Places in Chippewa County, Michigan
Transportation buildings and structures on the National Register of Historic Places in Michigan
Transportation buildings and structures in Michigan
1855 establishments in Michigan
United States Army Corps of Engineers
Canada–United States border