Precise Data About Train’s Speed At Time Of Crash Will Come From Onboard Recorder

Precise Data About Train’s Speed At Time Of Crash Will Come From Onboard Recorder

By Tom Avril, The Philadelphia Inquirer (TNS)

PHILADELPHIA — When you get right down to it, it was a question of physics.

At the site of the Amtrak derailment on Tuesday, the track had a curvature of 4 degrees. Imagine a giant circle with a diameter of nearly 2,900 feet, more than a half-mile. The track’s path would trace the outline of that circle.

The track also had a “superelevation” of 5 inches, meaning the outer rail was5 inches higher than the inner rail.

Given those parameters, a locomotive pulling seven Amtrak-size cars could safely travel up to about 55 mph, said Pennsylvania State University engineer Steve Dillen, who performed a rough calculation at The Philadelphia Inquirer’s request.

Early indications are that it was going nearly twice that fast, a National Transportation Safety Board member said Wednesday at a news conference.

Exactly how much faster will have to wait for detailed data from an onboard “event recorder,” analogous to what is known on airplanes as a black box. On trains, these devices electronically track speed, direction, distance, throttle position, and the use of brakes, among other data.

“It’ll tell them everything that train did,” said Danny Gilbert, a rail safety consultant based in Roanoke, Va.

Such recorders have been required on trains for years, but data sometimes have been lost in violent accidents. In 2005, the Federal Railroad Administration enacted rules requiring the devices to be crash-resistant.

Speed is typically measured using an axle-mounted generator that pulses with every revolution. Such generators often are mounted on more than one axle; their outputs can then be compared to correct any issues with slipping and sliding. The data is then transmitted to the event recorder.

It was not immediately known who made the box or boxes on the Amtrak train that derailed. Mayor Michael Nutter said they had been taken to an Amtrak facility in Delaware for analysis.

The section of track where the train derailed had a 50 mph speed limit.

Dillen, who coordinates the rail transportation engineering program at Penn State Altoona, said an additional 5 mph would probably be OK. Beyond that, he could not say.

Determining the exact tipping point, he said, would require a more detailed analysis involving the train’s center of gravity.

(c)2015 The Philadelphia Inquirer, Distributed by Tribune Content Agency, LLC.

Multiple injuries are reported during an Amtrak crash of a northbound train in Port Richmond on Tuesday, May 12, 2015, in Philadelphia. (Tom Gralish/Philadelphia Inquirer/TNS)

Gargantuan New Dinosaur Uncovered

Gargantuan New Dinosaur Uncovered

By Tom Avril, The Philadelphia Inquirer

PHILADELPHIA — It weighed as much as eight school buses.

Its neck looked like a section of oil pipeline. Its thigh bone alone was as big as a grown man.

Say hello to Dreadnoughtus schrani.

Drexel University scientists announced Thursday they had unearthed the heaviest known dinosaur for which a weight can be accurately calculated.

In many cases, the fossils of giant dinosaurs are largely incomplete, preventing scientists from making good estimates about their size, movement, and other characteristics. This one, found in southern Patagonia in Argentina, was unusually well preserved, with the scientists able to recover close to half of its 250-odd bones.

By measuring the circumference of the thigh bone and upper arm bone, the researchers calculated that this beast weighed more than 65 tons. And it was not done growing, as evidenced by shoulder bones that had yet to fuse together, said team leader Kenneth Lacovara, an associate professor of paleontology and geology at Drexel.

Lacovara named the animal after the dreadnought class of battleships from the early 20th century, so nicknamed because they feared nothing — dreaded naught. This dinosaur was so big that few predators would have dared to attack it, Lacovara said. But if one of them did, the dinosaur could have responded with a smack of its muscular, 29-foot tail.

“It essentially had a weaponized tail,” Lacovara said.

The “schrani” portion of the name is a tribute to Philadelphia tech entrepreneur Adam Schran, who helped fund the research.

The new find will contribute to scientists’ understanding of how the biggest land animals moved, and how they could sustain themselves — likely by gorging on tens of thousands of calories’ worth of leaves and plant matter every day, Lacovara said.

Photo via WikiCommons

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