Hendrick’s Folly : Old Guilford Avenue Diversion Tunnel

Jones Falls Conduit Old tunnel

After leaving the Goliath Chamber : Junction Chamber II , the explorer enters into an ancient like vestibule, only seen by few.  A passage into another outset, a unseen threshold of buried time . It is as symbolic as it is literal. Because at this point of the journey, you have crossed into the original, old section of the Bowels of Jonesy.

Upon entering Hendricks Folly, the air quality almost immediately changes. Almost like 2 distinct different atmospheres or gradients. Pockets of old, un-circulated air back in there. The explorer would push forward with much caution, as the air becomes thick, heavy and humidity laden. The explorer is concerned about this. It is assessed to be old air, stagnant air. The explorer continues to carefully assess the conditions. The mission could be aborted at any time. The density of the air in this section is evident when using flash photography.
jf conduit old hendricksProceeding forward, the tunnel landscape takes a drastic change. The floor is convex and brick laden, laid hundreds of years ago. For the first time, the explorer is one with the river. They walk in the river and not separate from it like the previous sections. The brick floor, is extremely slippery and the explorer ends up embracing the river, walking straight down the center. There is too much risk and energy expended by attempting to creep the sides of the sewer. The explorer finds that convex shape of the floor coupled with the ultra slick surface is difficult to remain up right. Water is leaking from the ceilings but the drops go unheard over the resonance of the rivers hum.


Note this excerpt from the “Annual Report of the Sewerage Commission of Baltimore City 1912” page 12

“The heading of the tunnel,under Guilford avenue, has been extended from the entrance of the retaining wall between Biddle and Chase streets to a point 25o feet beyond Preston street a total distance of 8oo feet”

Jones Falls Conduit tunnel 3

JF Conduit

Approximately 100 meters deep inside this section, there is a massive storm drain outfall that draining a number of large buried streams into the diversion tunnel. It is always pushing out a high volume of air. A drain within a drain. The internal outfall tube is concrete with a brick laden bottom . After some research, it is concluded that this is “Jenkins Run”. Which means this massive tunnel leads into another network of century old storm sewers. In fact, as of 1909, it was draining 900 acres of area. Another excerpt from a Sewerage Commission Report dated 1912″ page 12 states:

“The heading of the Jenkins tunnel has been extended through to meet the large tunnel a distance of 430 feet The rock excavated from this tunnel is being crushed and used to form the concrete conduits in the bed of the Falls below **** street”.

10 foot outfall storm sewer
Jenkins Run Storm Sewer – AVOID remains with us and reminds us of the ideal plan of action.

jf conduit jenkins run sewer

Jenkins – An ancient buried stream draining 900 acres

approaching jenkins run

Approaching the Outfall of Jenkins Run (left side) heading south.
As soon as the explorer navigates past this massive outflow,  a strong wind is pressing on their back. Again, this is a comfort to the explorer. In contrast with the previous stagnant air pocket, this fast moving stream of air enables further penetration.  Travel past this point continues to prove slow and strenuous. The sides of the tunnel remain convexed and angled upward. What feels like an eternity, the tunnel continues straight forward. Eventually, a slight bearing to the left is noted which obscures an possibility to assess what lies ahead. The tunnel wind begins to fade. After some time, the distant sound of rushing water is heard. The explorer is apprehensive in what lies ahead as the LED’s of the explorers lamps are only piercing the darkness so far. The tunnel finally straightens out again. The explorer finds themselves in the precursors of the Flume Chamber: Jonesy’s Last & Final Run.

The Mouth of Jonesy: Entrance
Jonesy’s Nares: Tunnel Section I
Triple Barrel Hall: Junction Chamber I
Penn Station’s Chasm Hall: Tunnel Section II
Goliath Chamber: Junction Chamber II
Hendrick’s Folly : Tunnel III
Flume Chamber: Jonesy’s Last & Final Run

Do not try to access these Conduits / tunnels / storm sewers! It’s dangerous. Getting caught within, or even trying to get in, probably could be considered a serious offense. Especially after the events of 9/11. These pages provides a complete virtual tour of the system that you can enjoy without risking your life or a criminal record. An explorer already risked their life, so that you can explore virtually from home… so stay safe, and stay away!