EMD Isolated Cab

[MEC407]

Thanks to "GaryL" of LocoNotes for forwarding this. The locomotive in question was BNSF SD70ACe #9159

"On April 17, 2011, about 6:55 a.m. central daylight time, eastbound BNSF
Railway coal train C-BTMCNM0-26, BNSF 9159 East, collided with the rear end
of standing BNSF Railway maintenance of way equipment train U-BRGCRI-15,
BNSF 9470 East, near Red Oak, Iowa. The accident occurred near milepost
448.3 on main track number two on the Creston Subdivision of the BNSF
Railway Nebraska Division. The collision resulted in the derailment of 2
locomotives and 12 cars. As a result of collision forces, the lead
locomotive's modular crew cab was detached, partially crushed, and involved
in a subsequent diesel fuel fire. Both crewmembers on the striking train
were fatally injured. Damage was in excess of $8.7 million"

Conclusions-excerpted


1. Because the isolated locomotive cab module detached from the deck of
the locomotive and was subsequently rotated and crushed, the crew could not
have survived.
2. Although the current locomotive crashworthiness standards include a
procedure to validate alternative locomotive crashworthiness designs that
are not consistent with any Federal Railroad Administration-approved
locomotive crashworthiness design standard, this requirement was not
effective in identifying the modular operating cab as an alternate design.


Probable Cause
Contributing to the severity of collision damage to the locomotive cab of
the striking coal train was the absence of crashworthiness standards for
modular locomotive crew cabs.


Recommendations New Recommendations *To the Federal Railroad Administration:
*


6. Revise Title 49 *Code of Federal Regulations* Part 229 to ensure the
protection of the occupants of isolated locomotive operating cabs in the
event of a collision. Make the revision applicable to all locomotives,
including the existing fleet and those newly constructed, rebuilt,
refurbished, and overhauled, unless the cab will never be occupied.
7. Revise Title 49 *Code of Federal Regulations* Part 229 to require
crashworthiness performance validation for all new locomotive designs under
conditions expected in a collision.

*To the Association of American Railroads:*
8. Revise Association of American Railroads Standard S-580 to provide
protection for the occupants of isolated operating cabs in the event of a
collision, and make the revision applicable to all locomotives, including
those newly constructed, rebuilt, refurbished, and overhauled.

Full text at: http://www.ntsb.gov/news/events/2012/re ... index.html

[Allen Hazen]

Am I right in thinking that GE has never used isolated cabs (of the sort involved in this disaster) on its North American locomotives? ... I think there was some description of a crew-comfort feature in a leaflet that Norfolk Southern distributed to its employees when the GEVO models (ES40DC for NS at that time) were new: it included elastomeric mounting of the engine: much of the benefit of an isolated cab (in reducing the engine vibration transmitted to the crew's station) but without compromising the connection of the cab to the frame.

[MEC407]

Correct.

I bet GE is feeling very good about that decision right about now.

[Engineer Spike]

Some GE units like the AC4400 and -9 have so many rattles and squeaks that they should have considered it. Most of them have a flag stick or spike between the control console and side wall to prevent it.

NS's SD70M-2 s have the cab directly mounted, while the ACe versions have isolated cabs. The doors seem to pop open on the direct mounts, unless the deadbolt is engaged, while the isolated cabs have less vibration, and are quieter.

[MEC407]

Squeaks and rattles are annoying, but I'll take safety over quietness any day of the week.

[Engineer Spike]

I'm sure that isolated cab units still have to pass the same crash standards, so they can't be that dangerous. It would be nearly impossible to engineer against every possible type of crash. The chance of a crash is slim. How many people only buy a car based only on its crash test rating? Why do some people still drive older cars which lack modern safety features?