CHAOS Report #10 - High Wind Blows Freight Cars Off a Bridge - May 2, 2015

Mechanical Liaison Officer's report by: Paul L. DeVerter II

Maunsel White has called our attention to an interesting video of high winds blowing some freight cars off a bridge. With thanks to WGNO television in New Orleans, here is an edited copy of the video that captures part of this accident.

The accident occurred around 10:30 AM on Monday April 27, 2015, as a Union Pacific freight train, traveling around 4 MPH, was crossing the Huey P. Long bridge across the Mississippi River. Four cars with containers plummeted approximately 70 feet to the ground in the Elmwood community of Jefferson Parish, Louisiana. In the video, you can see two containers and two platforms falling. Fortunately, no one was injured by this accident and the contents of the containers were general merchandise, rather than hazardous materials.

We do not know what type of couplers these cars were equipped with. They could be type E (non-interlocking) couplers, but more than likely they could be type F couplers with a lower shelf to provide some interlocking capability. However, some well cars for containers are multi-unit sets, where individual cars within the set are joined by a draw bar, or they are articulated, with two cars sharing a common truck. We do know that freight cars, unlike passenger cars, do not have a locking center pin to keep the trucks attached to the car body.

This accident makes you consider the pros and cons of the couplers (interlocking vs. non-interlocking), the draw bar or the articulation in this situation. Why didn't they prevent these cars from breaking away and falling to the ground. Why didn't they drag additional cars off the bridge to the ground below? Would the outcome have been different with a different type of coupler?

If Amtrak's Sunset Limited, equipped with Superliner cars, which have interlocking (type H tight lock) couplers, had been crossing the Huey P. Long bridge at that moment, how would the high winds have affected its consist? Superliner cars may not present as much "sail area" (square footage of their sides) to the wind as a double-stack container car, and they probably have a lower center of gravity than a double-stack freight car. In addition, the car body and trucks are joined with locking center pins. We surely hope they would have crossed the bridge safely in those gale winds.

I believe NTSB and FRA will investigate this accident, and their findings and recommendations will make interesting reading.

Southern Railway owned passenger cars that did not have interlocking couplers. I have heard that their rationale was that a derailment of one car on a bridge, trestle or high fill would not potentially drag multiple cars, or the entire train, off the bridge, trestle or fill, with cars tumbling down an embankment, falling to the ground or plunging into the water below.

Paul DeVerter