The Saturday Morning Post: Tunnels

There may be tunnels in my DNA.  The father of my father's mother, (Paternal-Maternal great grandfather) was a sandhog.  A tunnel digger. He started working  in coal mines in England, moved onto Tube tunnels in London, then to New York. If he hadn't done that work, and had not moved to North America to work, I wouldn't be here.  

His specialty was working in "soft soils" sand or mud. Things like tunneling under rivers or lakes.  Often they would build a wall, and pump in air, raising the air pressure to slow the water seeping in.  If this wasn't done carefully, the workmen suffered from decompression sickness.  A practice that probably shortened his life.  

Most of the New York subway system was built, the way the Wilkes Street Tunnel pictured above was built, a process called cut and cover.  In cut and cover they dig a trench, put the infrastructure in place, build the tunnel and fill back in over it.  Most cut and cover segments are relatively shallow. It is messy on the surface, but fast and much less expensive than digging deep tunnels.  

My great grandfather's work was long before modern tunnel boring machines, the work was done with drills, explosives, shovels, and rail cars to haul out the rock and dirt.  

There are two family legends from his work.  

In Chicago he built a water inlet tunnel under Lake Michigan.  They went a couple of miles off-shore,  lowered a large pipe from the surface to the bottom of the lake, lined it with brick and concrete to make it waterproof, then used that to start tunneling down under the lake floor, turning west and tunneling inland, while another crew started inland and tunneled toward the lake.  Part of how Chicago has fresh water from far enough off shore to not be impacted from contamination from the shore.  Part of the project that reverse to flow of the Chicago River from into Lake Michigan, to away from Lake Michigan so it didn't carry the contamination of the river into the water supply.  

In Detroit he worked on the road tunnel under the river to Canada.  It is shallow, only a few feet below the river bottom.  They were working in compressed air, and had a blow-out.  The compressed air blew the crew up through the bottom of the river.  Most of them came up swimming.  Not all returned to work, he did, finishing the job.  He went on to do a couple of water inlet tunnels out under Lake Huron.

I kind of enjoy tunnels.  The one above you can walk or ride a bike through. If you are in the area I can help you find it.