Passenger Trains > FRA: some psgr cars derail due to stiff suspensions

DEPARTMENT OF TRANSPORTATION
Federal Railroad Administration

Safety Advisory 2013-02; Low-Speed, Wheel-Climb Derailments of Passenger Equipment With "Stiff" Suspension Systems

> SUMMARY: FRA is issuing Safety Advisory 2013-02 to alert railroads and other industry members about low-speed, wheel-climb derailments
> of certain passenger equipment designs having "stiff" suspension systems. These derailments have occurred when such equipment was
> negotiating track with a high degree of curvature and crosslevel variations (commonly referred to as "track warp") that were still
> within the limits set forth in FRA's Track Safety Standards. The findings from the derailment investigations conducted by FRA and the
> respective railroads highlight the need to ensure that passenger equipment suspension systems are suitable for more-demanding track
> conditions found in low-speed operating environments. To avoid similar low-speed, wheel-climb derailments, this notice recommends
> that railroads and other industry members evaluate the trackworthiness of certain passenger equipment to determine whether
> the suspension systems meet truck-equalization industry standards, prevent wheel climb, and control static wheel-load distribution
> under the conditions and within the limits described in the notice; and take appropriate action to address the derailment tendency, if
> any, of the evaluated equipment. In order to minimize the risk of suspension spring failure, this notice also recommends that
> railroads and other industry members assessing the fatigue life of suspension springs and their corresponding maintenance intervals use
> a fatigue-evaluation load equal to the equipment's full-capacity loading conditions.
========================================

Briefly: the FRA findings are that modern passenger equipment, built to operate at higher speeds, have stiffer suspensions that, in
some cases, have been too stiff to remain on the rails at low speeds under certain track conditions that were still within FRA
standards. No injuries or serious collisions have yet occurred from derailments caused by this condition; however (quoting the FRA):

> ...one of the derailments resulted in the derailed train fouling the adjacent track on which a National Railroad Passenger Corporation
> (Amtrak) Acela Express train was traveling. Had the circumstances been different, a significant collision could have occurred. Thus,
> the recommendations in this notice are important not only in preventing low-speed, wheel-climb derailments themselves but in
> preventing what may be more serious consequences of such derailments.

=========================================

Industry sources say the equipment in question is the Bombardier multilevel car built for New Jersey Transit and for Montréal; and
to be built for MARC. In addition to a NJ Transit derailment, the derailment of a commuter train using those cars in Montréal may
also be due to this problem.

The suspensions are too stiff for curves and track irregularities at low speeds; a wheel lifts and climbs the rail; the car derails.
Softening the suspension would presumably solve the derailment problem but would make the cars incapable of safe operation at
speeds over 100mph, at which NJ Transit does currently operate theirs.



Edited 4 time(s). Last edit at 03/14/13 22:28 by GenePoon.

I thought those cars had airbag suspension that adjusts according to the load and track conditions?

One fix would seem to be to change FRA track standards to accommodate the needs of high speed operable cars. Well now that FRA has finally buckled on buff strength issues and is working on Tier III regulations, maybe there is hope on yard track standards too. :)

I thought the reason for a 'stiff' suspension was to enable a larger [ wider, usually ] car to be built, yet still keep its 'kinetic envelope' within the loading gauge. I think this is an issue for the truck designers myself -- and don't they say that 'truck design isn't just engineering, it's an art'-- or something like that....

Best rgds, SZ

I hope nothing goes wrong with the NJT multi level cars. I really like them.

Their ride quality is much superior to Amfleet cars. I've noticed this big difference many times when transferring trains at Trenton.

When you step off an Amfleet car; and directly board a NJT tri-level, you notice immediately the NJT cars don't rattle; shake; or rumble like Amfleet cars do. Also, they don't bang through interlockings with the jolt Amfleet cars give you; and the interior noise level is much lower.

I hope this low speed derailment situation doesn't turn our to be a Boeing "Dreamliner" like situation.

Joe



Edited 1 time(s). Last edit at 03/15/13 12:15 by floridajoe2001.

floridajoe2001 Wrote:
-------------------------------------------------------
> I hope nothing goes wrong with the NJT multi level
> cars. I really like them.
>
> Their ride quality is much superior to Amfleet
> cars. I've noticed this big difference many times
> when transferring trains at Trenton.
>
> When you step off an Amfleet car; and directly
> board a NJT tri-level, you notice immediately the
> NJT cars don't rattle; shake; or rumble like
> Amfleet cars do. Also, they don't bang through
> interlockings with the jolt Amfleet cars give you;
> and the interior noise level is mush lower.

NJT also goes at significantly lower speed Joe.... :)

New schedules out 3/24 have slowed NJT NEC schedules another 2 minutes. These 70 ton behemoths with piss-poor ingress/egress are terrible commuter cars.

Couldn't agree more.

They squeak, creak and rock... and they're new.
Sorry, I'll take an Amcan or Comet-V any day over these overweight sardine cans.


joemvcnj Wrote:
-------------------------------------------------------
> New schedules out 3/24 have slowed NJT NEC
> schedules another 2 minutes. These 70 ton
> behemoths with piss-poor ingress/egress are
> terrible commuter cars.

tmurray Wrote:
-------------------------------------------------------
> Couldn't agree more.
>
> They squeak, creak and rock... and they're new.
> Sorry, I'll take an Amcan or Comet-V any day over
> these overweight sardine cans.
>
>
> joemvcnj Wrote:
> --------------------------------------------------
> -----
> > New schedules out 3/24 have slowed NJT NEC
> > schedules another 2 minutes. These 70 ton
> > behemoths with piss-poor ingress/egress are
> > terrible commuter cars.


I actually can't disagree more about their riding qualities...I like them a lot better than the other NJT and SEPTA equipment.

And any commuter car on a system with heavy loadings is a "sardine can" by definition, otherwise it wouldn't be able to do its job properly. And US "sardine cans" are way more comfy than European ones (even if they do deal with track that's noticeably worse at best).

Good points about ingress/egress rates though.

A supple primary suspension doesn't necessarily translate into a ride that's incompatible with high speed operation. It might just mean that the trucks need to be a bit more sophisticated to counteract the tendency to roll and sway. Back in the 40's a roll-stabilized inside swing hanger truck was developed that was adopted by the Burlington route for its Zephyrs and bi-level commuter cars, also on the Peninsula commute service in San Francisco, and other places. They did a superior job of counteracting roll, even vs outside swinghanger designs, because the suspension was active. It is entirely compatible with soft equalizer springs (primary suspension).

joemvcnj Wrote:
-------------------------------------------------------
> New schedules out 3/24 have slowed NJT NEC
> schedules another 2 minutes. These 70 ton
> behemoths with piss-poor ingress/egress are
> terrible commuter cars.

Pretty soon they will be double the schedule time from the early 1970's.

I've spent a fair amount of time riding the multilevels (and other NJT and Amtrak equipment) throughout New Jersey. I agree that the ride quality is superior to Amfleet or anything in NJ Transit's single level fleet. As for the squeaking, yeah, I think that's the airbags or something similar in the suspension that you can hear sometimes.

I would suggest the solution is improving the standards of our piss poor track. On decent track they seem to do quite well - riding a Princeton Junction express along the NEC at 100 mph almost makes you forget you're riding NJ Transit! :)



Edited 1 time(s). Last edit at 03/15/13 13:53 by hsr_fan.

joemvcnj Wrote:
-------------------------------------------------------
> New schedules out 3/24 have slowed NJT NEC
> schedules another 2 minutes. These 70 ton
> behemoths with piss-poor ingress/egress are
> terrible commuter cars.

Didn't they add extra time to account for the fact that one of the tracks between Jersey Avenue (County) and Trenton will be out of service this construction season for high speed upgrade?

No idea why, and there is no explanation in the heading that schedules were modified for track-work. They have done so in the past for extending RVL schedules for 2 minutes when replacing bridges near Plainfield.