TOLEDO, OH (WTOL) - It has been a booming industry in our area for decades, but not many people know about it. However, it is why so many Lake Erie freighter ships dock here in Toledo over the winter.

Currently at the Toledo Docks, just south of where the Maumee River dumps into Maumee Bay, nearly a dozen cargo freighters are docked and crawling with workers.

With ice clogging the seaways, these shipping companies take the winter to make any needed upgrades or repairs.

"Maintenance on the main engines, overhaul on the engines, cat generators, conveyor systems; just to keep everything going that wears down over a year of time running," boat engineer for American Century Daniel Hutchison said.

H Hansen Industries, based in Toledo, runs the largest freighter repair operation in the Great Lakes.

The work is not only vital to keep these freighters a float, but a huge economic impact for the region.

"There's probably 600 or more involved with other contractors, and it brings maybe 100 million dollars a winter to the city of Toledo," Hansen president Tony La Mantia said.

Though larger facilities are available at other ports, these companies chose Toledo because of the relationships they have built with Hansen and the ease of access for the ships.

"There's other facilities you could go to, but that'll cost more because we're out of our shipping channels," Hutchinson explained. "If you overload one place too much, they won't be able to work increase load. And this is in our normal shipping routes, so we don't have to go off course so much."

La Mantia says they have other facilities in Huron and Cleveland, but would rather have all the repair work done in Toledo. Therefore, he is working with the Lucas County Port Authority trying to add more docks to house even more ships here.

"They have a couple more docks that might be available that are not in use right now, and we've been working with them and we're going to continue to work with them and try to get those so we can bring more ships here," La Matia said.

The repair season wraps up at the end of March when the Soo Locks open up to the upper Great Lakes. That gives these workers a few more weeks to get these repairs complete.

All work must be inspected by both the American Bureau of Shipping and the Coast Guard.