Baltimore is a city built on tunnels. President-elect Barack Obama and his entourage were scheduled to pass through two of our longest railroad underground passages, one in East Baltimore along Hoffman Street, the other lengthy one in West Baltimore that runs under Wilson Street.

I've found that Baltimoreans are fascinated by stories about our dank, underground byways and grow wide-eyed at tales about unused, sealed or hidden chambers. Some of these stories are false; others are merely confused - after all, a well-made tunnel is out of sight on purpose. (I recently heard of a fellow who kayaked under the city in the tunneled Jones Falls.)


I thought my list of tunnels was fairly complete, but then my friend Rudy Fischer called and told me he'd been dropped in a bucket and taken on a tour of a local oddity - the 29th Street tunnel under Sisson Street.

Constructed between 1926 and 1927, this passage is 160 feet long, 30 feet wide and was once used by passenger and freight trains of the Maryland and Pennsylvania Railroad, that wonderful little steam railroad that wound through Stony Run Valley, Roland Park, Woodbrook, Rodgers Forge, Towson, Glen Arm, Fallston and Bel Air and ended at York, Pa.


The railroad sadly went out of business here in 1958 (parts of it operate in Pennsylvania), and the city lost no time claiming its space and filling the tunnel's north end with tons of rock and materials used in the construction of the Jones Falls Expressway. On a search for evidence of this elusive tunnel last year, I found it was as deeply buried as a pharaoh's tomb.

The Ma & Pa Railroad has a devoted fan club, and its members have preserved its memory along with maps and photos of this tunnel, which was constructed for the railroad by the city and its engineers when they extended 29th Street and bridged the Jones Falls Valley in the 1920s and 1930s.

It seems the Ma & Pa tunnel was never truly destroyed - it had tons of earth piled around and on top of it as the landscape changed in this corner of Remington.

For the past year, Carp-Seca Corp. has been working under a $40 million contract with the city to build a sewer tunnel to serve homes in much of North Baltimore. The contractors are working 80 feet under the railroad's right of way through Wyman Park for a 6,000-foot stretch of sewer tunnel from Linkwood to Falls roads.

"We are on schedule and moving along quite well," said John Lancey, the project manager. "We are taking delivery next week of a large, unique piece of equipment manufactured in Germany and brought in through the port of Baltimore. It is an 8-foot-diameter and 120-foot-long tunnel-boring machine that will be used to bore the tunnel through the rock upon which the railroad bed sits."

The contractors found that the pre-existing Sisson Street rail tunnel was in good shape and would hold the sewer pipe. So they opened it up and cleaned out the rock infill. They were able to route the sewer line through it without having to do more labor-intensive excavation.

They were also open to letting the Ma & Pa Railroad Historical Society members in for a look and to shoot video along the way.