U.S. President Donald Trump recently announced his support to build a new navigation lock between Lakes Superior and Huron, presently the location of a largest navigation lock between the North Atlantic and the Great Lakes. Any malfunction of the lock could halt ship transportation between these two lakes and inflict a serious setback to the American economy.
The history of North American inland ship transportation predates the building of the railways. Despite the small size of the early and locally built sailing ships, ship transportation provided economic benefits to communities located around North America’s Upper Great Lakes, courtesy of the absence of navigation locks on the shipping passage across Lakes Michigan, Huron and Erie between Chicago and Niagara Falls. The Erie navigation canal connected Niagara Falls to New York City and allowed passage to comparatively small vessels. Generous water depth and wide navigation channels allowed larger vessels to sail across the Great Lakes.
The construction of single-step navigation locks between Lake Superior and Lake Huron extended the operating range of large ships to a region where iron ore was readily available. As advancing technology allowed for the construction of larger ships, such vessels proved far more economical in bulk transportation than the competing railways. By the 1960s, the American Corps of Engineers rebuilt the Poe Lock at Sault Ste Marie to the same length (1,200 feet) and width (110 feet) as navigation locks along other American navigable inland waterways, except that the rebuilt Poe Lock offered 32-foot navigation draft.
Despite the annual winter closure of three months between January and March, some 10,000 vessel transits occur annually at the navigation locks between Lakes Superior and Huron. Since 1986, concerns have been raised over the impact of a possible malfunction of the single large navigation lock.
While then President Reagan promised to build a second parallel navigation lock, the American Congress is alleged to have not allocated the funding to undertake such a task. Now more than 30 years later, Trump announced his intention to build a new large navigation lock to provide twin locks between the lakes.
The announcement to build a new lock invites discussion about advances in ship building and whether there would be any merit to building a larger navigation locks to transit even larger ships. On the Southern Mississippi River and Lower St Lawrence River, vessels are allowed to sail a beam of 140 feet, and questions need to be asked about operating such a beam on the Upper Great lakes. Could the Erie shipyard build a bulk carrier vessel of 140-foot beam and at the same draft and length as present day Upper Great Lakes large ships?
The precedent from the widened Panama Canal suggests the possibility of building a wider navigation lock at Sault Ste Marie, perhaps even include a water saving reservoir. Or does building a wider ship cause unsolvable technical problems? Is there enough market demand in bulk freight transportation for ships to carry 25 to 30 percent greater payload? Researchers at University of Michigan examined a two-section coupled ship that could perhaps be built to 1,600-foot length. Is there any market application for a bulk carrier ship built to both 33 percent greater beam and up to 50 percent greater length?
Wide Ship in Narrow Channel
Ships sailing between Lakes Huron and Erie pass through both the St Clair River and Detroit River where ship bow waves could cause shoreline erosion. A catamaran type hull with a narrow channel between the hulls could, with forward propeller assist redirect most of the bow wave into a fast stream flowing rearward underneath the hull and with a comparatively small residual bow wave. Retractable deflectors built next to the bow and including forward propellers could convert most of the bow wave to fast rearward flowing water streams along the sides of the hull.
The St Clair River has a short, narrow section of 800 feet while the narrowest section of the Detroit River is 2,400 feet. A massive reduction in speed in the narrow section of the St Clair River or installing shoreline reinforcements would both minimize shoreline erosion caused by ship bow waves.
A twin hull bulk carrier with 60-foot hulls and a 20-foot channel between the hulls could generate a powerful rearward flowing water stream in that channel. When operating in wider channels, a door would lower at the bow to duplicate the bow of a conventional ship.
Several governors of states located around the Upper Great Lakes welcomed President Trump’s support to build a new navigation lock between Lakes Superior and Huron. There has also been support for Trump from the Great Lakes ship transportation industry. Given the advances in ship building technology, stakeholders will need to discuss the size of the navigation locks. Should the new lock be built to the same size as the existing lock or should it be built to a large size to transit wider and possibly longer ships. Coupled ships (tug barges) do sail American coastal service.
Stakeholders need to discuss as to whether a super-size coupled ship could feasibly sail on the Upper Great Lakes, one option being a super-size of barge being pushed and navigated by a super-size of tug capable of up to 25,000 horsepower offering a cruise speed of 16 knots. Ship designers would need to determine the feasibility and possibility of building an articulation coupling capable of both relative vertical movements resulting from pitching as well as relative roll movement between the two sections of vessel. Transportation economists would need to determine the merit of sailing larger vessels on the Upper Great Lakes.
Trump’s announcement voicing support to build a new navigation lock between Lakes Superior and Huron has won support from state governors in the region as well as from some ship operators. His announcement invites discussion as to whether a future lock is to be built at the same size as the existing Poe Lock or be built to a larger size to transit larger vessels. Stakeholders need to discuss the relative merit of sailing larger vessel on the Upper Great Lakes.
The opinions expressed herein are the author’s and not necessarily those of The Maritime Executive.
SOURCE: The Maritime Executive