diesel fumes, passengers, and tunnels

[wborys]

So the Hoosac tunnel is a little over 4 miles long, I think. It's advertising fall foilage excursions,
and I assume other passenger trains are routed through also. I'm not sure about lengths of other
passenger-carrying tunnels. BUT-

What provisions are made to keep passengers safe from diesel fumes while in these tunnels?

[Literalman]

Hoosac Tunnel was built with ventilating shafts. I don't know whether they still function.

When trains pass through the First Street tunnel under Capitol Hill in Washington, DC, the crews are supposed to turn off the ventilation equipment that draws in the outside air and turn it on again once the trains leave the tunnel.

[TomNelligan]

Hoosac Tunnel has not seen regular passenger service since the late 1950s, so the effect of of diesel fumes on passengers is not an issue there. But very long tunnels that are not electrified generally have ventilation equipment to keep the air inside breathable. The US champion is the nearly eight-mile-long Cascade Tunnel in Washington state, which is used by Amtrak's Empire Builder and numerous freights on BNSF's former Great Northern mainline. The Wikipedia entry on the tunnel contains a good description of how it is ventilated.

https://en.wikipedia.org/wiki/Cascade_Tunnel

[R36 Combine Coach]

The NJT (Lackawanna) Tunnels that serve Hoboken Terminal are about a mile in length and have two shafts, dividing the tubes into "thirds" (east 1/3, center 1/3, west 1/3).

The Empire Corridor (West Side Line) has a 4 mile tunnel section from about 59 to 122 Streets. The P32s operate in diesel mode here (electric in the small connector tunnel at 34 Street).

And PHL 30 Street lower level (which is underground) has and does allow diesels. The other underground station I can think of with diesels in regular service is Back Bay.

[DutchRailnut]

Empire tunnel is less than mile long from 34th street to about 44 street, rest is not tunnel but it does have highway over tracks till around 90 street.

[TomNelligan]

The other underground station I can think of with diesels in regular service is Back Bay.

Back Bay does have fume/ventilation problems, but it's not "underground" in the sense of a subway station. Up until the current station was built 1980s, the tracks were in an open cut below street level. During the Southwest Corridor construction the cut was roofed over to create a mini-park. Vents were provided but they have proved insufficient for the current level of traffic.

[mtuandrew]

Montreal's Gare Centrale is underground and allows diesels. I'm not sure if the Mount Royal tunnel allows them though.

[bdawe]

Montreal's Gare Centrale is underground and allows diesels. I'm not sure if the Mount Royal tunnel allows them though.

I believe Mt. Royal is electric only, which is why they purchased all those ALP-45, and why they retained those 1917 Canadian Northern box cabs until 1995

[Arborwayfan]

Amtrak tells passengers not to pass between cars (that is, not to open car doors) while going through the Moffat Tunnel on the California Zephyr (8.2 miles ?).

[MACTRAXX]

PHL 30 Street lower level (which is underground) has and does allow diesels. The other underground station I can think of with diesels in regular service is Back Bay.

R36 and Everyone:

Philadelphia 30th Street Station's lower level was designed for the use of electric traction.

Diesel trains arriving or terminating at 30th Street are usually kept away from the staircase areas especially
when they are operating in full HEP mode. NJT ACL trains - which typically operate off of tracks 1-2 (and at
times 9-10) only use full HEP while boarding before departure - on arrival they turn down HEP as soon as possible
and move away from staircase proximity. In some cases - especially when F40PH locomotives were used before
they were retired - trains would board from the north ends of platforms to allow locomotives to idle outside of
the closed-in canopy area meaning that there would be a substantial walk up to board trains - especially the short
Harrisburg trains averaging three cars when they used non push pull Diesel hauled trains on this route.

MACTRAXX

[ExCon90]

PRR timetables from 1960 contain a special instruction requiring that the heat switch on the Keystone equipment be placed on LOW HEAT between the east portals of the East River and the west portals of the North River tunnels, and also between ZOO and ARSENAL (bracketing 30th St. Station). The Chesapeake Region timetable contains the same provision when a train is detained in a tunnel (read B&P and Union Tunnels) or other "restricted area." As to the OP's original point, the Chesapeake Region timetable states that the reason is to avoid having diesel fumes drawn into the coaches. (When the switch in any car was placed on LOW HEAT the diesel responded accordingly for the entire set of equipment, so in that position the diesel was not switched off completely but was throttled down to reduce emissions.)