NJT HOBOKEN TERMINAL ACCIDENT THREAD

[jonnhrr]

Path service to Hoboken resuming at 3 PM according to their web site:

PATH service to/from Hoboken Station (HOB-33 & HOB-WTC) will be restored today at 3pm. NJ Transit Rail Terminal will remain closed.

Jon

[JimBoylan]

Just to clarify Ptc would not prevent this type of accident, it is an overlay to the existing signaling system and designed to enforce Maximum Authorised Speed (MAS) and also prevent signal violations, it would have kept the speed to the timetabled speed in the terminal but would not stop the train before reaching the bumper.

Some places treat the bumper, or a signal on or close to it, as a real Stop Signal, whose violation Positive Train Control is supposed to prevent.

[litz]

Would PTC even be active in this case though? This is inside a station, which itself is inside a yard ... is PTC even designed to be implemented or work in this environment?

[mohawkrailfan]

Penn Station is already a mess. If you're planning to travel from NYC to NJ tonight, and you're not already out of the city, I recommend staying late.

[DutchRailnut]

Would PTC even be active in this case though? This is inside a station, which itself is inside a yard ... is PTC even designed to be implemented or work in this environment?

PTC and Cab/ATC does not work in terminal area's, once speed is down to restricted speed it basically no longer works.
yes on main track PTC works, but it stops a train way before a red signal , why??? because it needs a safety margin, which is something like 300 feet.

[swampoodle]

All true. PTC by its nature becomes highly impractical in a terminal environment, and would potentially not be active in the station, even if the system were operational on the main.

[Crabman1130]

Heard it was track 5, which is pretty common for 1614 (I ride it with some frequency). Anyone know if there was a cast iron or concrete bumper on this track? Hope the engineer is OK.

This is what I could find for track 5 in Hoboken.

[justalurker66]

All true. PTC by its nature becomes highly impractical in a terminal environment, and would potentially not be active in the station, even if the system were operational on the main.

The NTSB spokewoman (Bella Dihn-Zarr - Vice Chair NTSB) spoke at 5:36pm ET.

At that time the NTSB had not been able to access the control car due to safety issues (collapsed canopy).
The NTSB said that there were outward cameras that they will be recovering.
The on scene investigation should take 7-10 days.

Responding to a question about PTC: The NTSB has been recommending PTC for 40 years but they will not comment on whether or not it would have helped.

[FLHerne]

PTC by its nature becomes highly impractical in a terminal environment, and would potentially not be active in the station, even if the system were operational on the main.

The UK equivalent, TPWS, is fitted before all terminal platforms - 12mph overspeed grids at 60 yards from the end, usually with a higher-speed set further back. There's some glitchy behaviour when trains stop directly above the grids, but for the most part it works alright.

[SCB2525]

PTC doesn't have the ability to enforce speeds below 15MPH? I find that hard to believe, and certainly you can install a transponder on the entering end of the platform.

Is the timetable speed in the station Restricted or Restricted not to exceed X?

[Limited-Clear]

Ptc can and does enforce under 15mph, it does not enforce a positive stop before a bumper, Jim why would you put a signal on a bumper and please tell me where this is actually in place, I'm not disputing what you say but I have never seen or heard of that, if you violate the end of the track you don't have a signal violation you have a crash/derailment.

I don't know what rules are in effect at Hoboken (not my territory), but most terminals are not classed as main tracks, does Hoboken have cab signals? If so reports of 30mph seem unlikely

[Matt Johnson]

This is what I could find for track 5 in Hoboken.

Must be an older photo, but accurate as far as the tracks are concerned. Here's one I took at that spot just a couple of months ago.

[Ridgefielder]

Ptc can and does enforce under 15mph, it does not enforce a positive stop before a bumper, Jim why would you put a signal on a bumper and please tell me where this is actually in place, I'm not disputing what you say but I have never seen or heard of that, if you violate the end of the track you don't have a signal violation you have a crash/derailment.

I've seen it in the NYC Subway- at the Grand Central end of the Times Square Shuttle there are signals just short of the bumper blocks on the stub tracks.

[Ken W2KB]

Just because the wires were disconnected from the high voltage source, if they were not directly connected to ground, you really don't know what the voltage on the wires is. Due to stray leakage from nearby high voltages, or residual charged capacitances, the voltage could be anywhere between the high voltage and zero (ground). If the wires were still charged to some high voltage, you couldn't pull a lot of current out of it and power anything, but the residual charge could easily be enough to hurt someone badly. That's why you ground the wire, to be sure it is at zero volts compared to ground.

It's a similar effect as in the olden days when you opened the back of your TV, etc, to change vacuum tubes to try to fix your set if it isn't working right (if you're old enough you remember taking the tubes down to the tester at the drugstore...). Even with the set unplugged, the power supply or HV capacitors could still be charged, and if you accidentally shorted them it was more than enough to scare the .... out of you, literally, at a minimum, and it could easily do far worse than that. Any TV repairman would tell you the golden rule was only one hand inside the set at a time (so you didn't accidentally put high voltage on one hand and ground on the other). JS

That is precisely why I stated that grounding is not required, only a verification that the wires were not energized from any source. Inductive charging would be possible if higher voltage lines were parallel in close vicinity and thus emf field coupled, but capacitive charge is very unlikely. NJT may have voltage support or power factor correction capacitors in its system but those would be on transmission, not the catenary itself.

Electric utilities tag out circuits much higher (up to 765kV) than the NJT 25kV without a need to ground the circuits for maintenance work. Essentially the same as blue flagging railroad rolling equipment to indicate do not move. Grounding does not prevent re-energizing, it trips the breaker after it closes, so personnel are still at risk for a second or two at least if someone improperly closes a breaker.

[Ken W2KB]

There can/could also be 'back feed' into ANY downed/compromised power lines (catenary or otherwise) that may happen to have backup generator or battery backup sources.
ANY downed electric wires should be considered LIVE until proper authorities give a CLEAR to operational/rescue personnel.
This is the FIRST thing we are taught in Emergency Management classes about electric hazards.

Agreed which is why I stated grounding was unnecessary, but verification that the conductors were not energized was sufficient.