Lower Gwynn’s Run Trunk Drain

A large tunnel system that extends for miles and holds a deep forgotten history of the city.

The Entrance Culvert: The first railroad culvert of its kind in the country.Build date 1829.

The Furnace

The Grand Staircases will go here (need photo).

Junction Chamber 1

Eastern Gwynns: Franklin & Pulaski St Branch

Upper Gwynns

PAGE IS INCOMPLETE

Reference and Credits

  • Special thanks to ZOZE for Gwinn’s Furnace thumbnail
  • a) Maryland Historical Magazine , 1921 – https://archive.org/stream/marylandhistoric1619mary/marylandhistoric1619mary_djvu.txt
  • b) USGS 01589352 GWYNNS FALLS
  • Edit History:
  • September 2017 – Article created.
  • October 2017 – Additional information added.
  • December 2017 – Calculations .
  • September 2018 – structural Dates Corrected.
  • April 4, 2019 – Factual corrections,sources added, reformatted text and corrected grammar. moved first personal comments to a journal entry I. removed outfall output volume guestimate calculations and moved to journey entry I
  • April 12, 2019 Post is converted into a gateway page, for entire storm sewer system.Working progress
  • March 2, 2020: Complete restructureing after site migration.

M.J.MM Storm Sewer








Drains McMechen respectively, including Mosher and John. Was relieved by Druid Hill/ North Avenue Intercepter. It varies in size from an arched culvert 12 feet wide and 15 feet high to a circle 4 feet 6 inches in diameter. Drains out the Rutters Run Lateral. An old, forgotten, buried yet ever present stream. Extensive system with 2 significant junction chambers. Its tunnel system drains out an area known to be notorious for small streams,springs and quicksand. The same engineering grief was had during the construction of the B&O railroad tunnel that lies just north of this tunnel. Exploration of these tunnels requires a man raft as it is block by a deep pit of water of unknown depth. It was once thought that a man raft would be required to access this system but later explorations proved otherwise. However, it has come to our understanding that old drains suffer from deep silt deposits and stagnant air making their penetration and documentation quite treacherous.

Exploration & Discovery Abstract

This tunnel lies within the zone of Baltimore’s “Forgotten Triangle”. For years this tunnel was missed, as it is tucked away in thick brush and mangled railroad waste and appears irrelevant to the untrained eye on satellite imagery. However, one day, the explorer took note of a small, slow flowing stream (almost stagnant in some places) that was tucked away in the corner of the Forgotten triangle. It was decided to follow this stream, with little hopes that it would turn up anything more then a small stone storm drain. The terrain leading up to the drain is treacherous. Mangled, metal and trash strewn everywhere making the explorer cognizant of every step he takes. There is evidence of old foundations and structures and a reconstructed railroad utility. bridge After about a 10 minute traverse, you don’t see the tunnel until your right on top of it due to tree branches and snake like vines covering its entrance. At this point, its like your down in a hole. The side embankments are about 15-20ft above your head but the stone granite arch tunnel itself is like bored into a 40 foot high embankment.

storm drain outfall M.JMM
M.JMM Outfall Tunnel looking in.





North Avenue and Druid Hill Avenue Storm Sewer Tunnel



north ave howard st final outfall
West side Storm Sewer Interceptor
Large interceptor storm sewer drain system built to drain out an area that was known to have many small streams and springs. A 2 fold problem existed, the old Druid Hill Avenue storm sewer was of insufficient capacity and the old McMechen Street Drain was already at over capacity. 2.1 meter (7 ft) oval , Brick Arched Culvert, with a masonry granite floor laid in American hydraulic cement 14 inches thick. This drains drops significantly in elevation along its course to outfall and accomplishes this via multiple vertical drop shafts or vertical drop wells (4 total).




Adventure/ Urban Exploration Video shot soley on a GoPro Hero+ and Canon T3i in this exact drain found below.

Vertical Drop Shafts featuring shafts constructed out of granite masonry that was laid 8ft x8 ft deep square outer diameter (OD), with final sizing 4ft x 4ft internal diameter (ID). The original iron cradles sit at the bottom of these shafts to smoothly drop the water from elevation to the floor. These iron cradles have proven to a very robust and enduring construction method. 1 significant junction chamber. Extensive small laterals. 1.5 percent grade.
In connection with the above were constructed the outfall of the sewer of heavy rubble broken range masonry at the west side of Jones Falls with its wing walls parapet and timber apron the four vertical drops eight feet square with cast iron inverts and the sides and ends faced with heavy dimension stone with depths of eighteen six and one half four and one half and five feet respectively the first two being excavated in hard and rotten rock requiring blasting On the line of the main tunnel four shafts were constructed to depths of 27ft, 43ft, 41ft, and 28ft feet respectively for the purpose of hoisting and lowering materials for the construction of the sewer Of the above there was completed during the year 1895.(ref a.)

Apparently this old storm sewer got in the way during the construction of a section of the B&P tunnel. Later they ended up utilizing it for the drainage of the train tunnel. Reference below.

Another unscheduled problem was encountered in the John Street Tunnel where a storm sewer crossed under the invert after following its centerline for about 200 ft. Originally an old brick-lined barrel and arch, its top had been partly uncovered, probably during invert work in 1916-1917, and slabbed over. Because this structure was at a higher elevation than indicated on the plans, it was severely damaged during invert scarification. (ref b.)

It should be noted that this particular drain had an incident of surging during its first exploratory documentation. The reason to this day is unknown. No precipitation was recorded that day in the area served by this storm sewer let alone watershed. Documentation exist that a section of the John Street tunnel, that passes near by requires water pumps to pump out a low lying area inside the tunnel. It specifically states that the water is pumped into a nearby storm sewer. It can only be assumed that it does so in intervals, such as like a sump pump behaves, which in turn would explain the sudden surge of water. Referenced to this coming soon. here: The sumps were located under the tracks at the south portal to cut off the entrance of outside water supplementing the original pumping chamber, and in the Wilson Street Tunnel just short of the rock line of the intersection with the tunnel invert. Water from the sumps is pumped to the city storm sewers. (ref b.)




north avenue at drop well

REFERENCE
a.) Annual Report of the City Commissioner to the Mayor of Baltimore 1889
b.) Rehabilitation of Amtrak Baltimore and Potomac Railroad Tunnel in Baltimore, Maryland. Pg 31-33, June 1981