Penn Station's Hall JFX Diversion Tunnel

Penn station’s Halls | JFX Diversion Tunnels

In Urban Exploration - Drains/Sewers by Ronnie K0 Comments

| Upper Jones Falls Conduits: New Construction Tunnel |

Proceeding past Junction Chamber 1, Triple Barrel Hall , the 3 intake conduits converge into 2 massive hallway like tunnels,running in parallel. Again these conduits composition are made up of concrete all the way around and are mistakenly referred to as the Jones Falls Conduits. The daily flow of the Jones Falls river runs through the western conduit, while the eastern conduit usually host a small stream of water being fed by 2 underground streams that outfall in here. Immediately after Triple Barrel Hall the tunnels bear slightly the right before straitening out again. While these tunnels do not run at depth, the enormous size of these underground tunnels are remarkable. More like underground sanatoriums. Like massive, never ending hallways.


Two conduits run in parallel under a major highway and eventually run out in front of a major Train station, which can be heard at times. Modern concrete construction, rectangular shape, that do no sit deep within the ground. Approximate Height x Width: 8-9 meters high (26-29 feet) and 5.0-6.0 meters (16-19ft) wide. Eastern tunnel serves as an outfall for 2 large lateral drains, one with a known SSO/CSO relief point. The N. Charles Street Storm Sewer & the Lovegrove Alley Storm Sewer. Tunnel Section length after Junction Chamber #1 1000 meters. Formidable Zone of Isolation towards the back end of the tunnel before Junction Chamber 2.

Penn Stations chasm JF CONDUIT

Penn stations chasm hall
There are 2 large drains and a number of small drains that are positioned in the upper portion of the walls, towards the top of the ceiling. The 2 of the larger outfalls, are the Charles Street Sewer and Lovegrove Alley Sewer. They serve as combined sewer overflow outlets (SSO/CSO) and appear to have the capacity of 700 – 1000 cubic foot a second drains.

Drain inside of a drain

Charles Street Sewer & CSO/SSO #152 Discharge Point

JF Conduit Graffiti artist baltimore

1202 said to “KEEP GOING” so we kept going

There is some notable graffiti art towards the end of this tunnel, just prior to the Formidable Zone of Isolation. One of the most impressive graffiti in the entire tunnel lies at the end of this section. Impressive due to the fact that it spans almost the entire face of the wall. Further research brings to light this style of graffiti is known as “Blockbuster graffiti” or “Roller Graffiti”. Its a massive piece of art with a hand holding a bottle, tagged by 1202 that reads “KEEP GOING —>” .

Looking North

You see, at the back end of these great tunnel halls the explorer crosses into which is known as the Formidable Zone of Isolation. It is an area that is poorly ventilated and with no surface access in the event of an emergency. There are 2 ceiling portals in this zone that are not vented and do not have built in ladders, which do not make them self serving in the event of an emergency. The closest manhole portal (that could act as a self serving rescue tactic) after this zone is 20 meters inside of Jenkins which is about 400 meters away. These access portals provide the tunnel natural ventilation and also the hope of emergency rescue. There is always the concern of air quality here as the breeze seems to stop or more or less slow down here. The temperature and scent of the air takes a notable changes. The explorer always notes this spot as nearing  the original 100 year old section of the Jones Falls Conduit, the Guilford Avenue Diversion Tunnel. Also known a, Junction Chamber II, the Goliath Chamber. Perhaps this is where the “KEEP GOING” comes from, because you are almost there!

hall maw

The Mouth of Jonesy: Infall Stage
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 : Guilford Avenue Diversion Tunnel
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!

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