This is the original Detroit / Windsor tunnel – the Michigan Central Railway Tunnel, opened in 1910. Many people dont even know its there, but it passes behind Michigan Central Station, and submerges before you get to Fort Street.
For a short time, this was called the “Jobs Tunnel” because they were going to covert it to truck traffic to relieve the current tunnel and existing Ambassador Bridge. Nobody talks about that anymore now that there are few jobs to drive any place for, and the website currently has a single ironic page:
Here is what the tunnel looked like back in its heyday.
Look at that little man door at the top of the staircase between the tunnels – how creepy do you think THAT is to walk through ?
The tracks have most recently been used by Canadian National, but is now owned by something called Borealis Transportation.
The original trains that ran the tunnel were electric. It is a modern misconception that electric transportation is some near distant future technology. It was one of the original technologies for transportation.
Here is a Detroit River Tunnel Company map from 1916, showing the location of the tunnel as it crosses the river and an International border.