While plans rapidly advance to build a $2 billion bridge over the Detroit River, backers of a $400 million project to build a modern rail tunnel under the waterway continue to seek funding and government approvals.

The Continental Rail Gateway tunnel project has been in the planning and financing stages since it was formally launched in 2001, and is the result of another tunnel project that got its start 30 years ago this week.

From the archives: Detroit could be major U.S. rail gateway (June 3, 1985)

According to the June 3, 1985, edition of Crain’s Detroit Business, two rail companies bought the tracks that connected Detroit and Windsor via a twin-tube tunnel that opened in 1910, and they were seeking bidders on a study for possible enlargement of the tubes. The reason? So they could handle larger stacked rail cars used for the automotive industry.

At the time, taller-stacked rail cars (and those of competing rail companies) were forced to use a ferry to cross the Detroit River, adding delays and costs to moving goods.

What is known officially as the Michigan Central Railway Tunnel was built for $8.5 million by the Detroit River Tunnel Co. for Canada Southern Railway and opened in October 1910 — long before the auto companies began building millions of large cars and trucks in metro Detroit and Ontario.

The need to improve efficiency fueled Montreal-based Canadian National Railways Ltd.’s 1985 purchase of the 8,373-foot-long tunnel from Consolidated Rail Corp. of Philadelphia, better known as Conrail.

Canadian National, then owned by the Canadian government and privately owned, Calgary, Alberta-based Canadian Pacific Railway Ltd. jointly bought the old Canadian Southern Railway line between Detroit and Niagara Falls for $25.2 million in a deal that included the tunnel, which has its Detroit entrance just southwest of the post office at West Fourth and Eighth streets.

CN solely took over tunnel operations on May 1, 1985, from the Conrail-owned Detroit River Tunnel Co. It withdrew from the project a year later to focus on a tunnel project between Port Huron and Sarnia (which opened in 1994).

An initial estimate, prior to the study, was that it would cost $7 million to enlarge the tunnel. It was to be part of a $41 million plan by Canadian National and CP Rail to improve the entire rail line.

The tunnel had been built by sinking 80-foot-long steel tube sections into a 13-foot-deep trench in the riverbed. They were then covered with concrete.

The interior of the tubes were lined with concrete.

After the 1985 study was done, it was determined only the northern of the two tubes could safely be expanded.