قالب وردپرس درنا توس
Home / Business / Broken shaft caused red line derailment

Broken shaft caused red line derailment



The train reached that condition as a result of holes in the inspection plans and lost warning signs, investigators found. While axle damage sometimes occurs on heavily used vehicles, the train in question was a few weeks away from a semi-annual inspection that would have detected it. Also, crews conducting preventive inspections about every three months had not checked the ground, a related part that helps keep the train electrically grounded, which was damaged and caused the shaft to become fragile. BTA Deputy Director Jeff Gonnville said the transit authority had no records of any past incident with the ground. Going forward, MBTA will work to prevent these problems from recurring. Ultrasound inspections will now be conducted annually instead of every two years, and regular inspections will include careful examination of the earthing unit for any damage that may occur to the shaft or other parts. "We have affected a lot of people on the Red Line over the last few months," Gonneville told reporters at a Monday briefing. "It's our duty to make sure this doesn't happen again." Gonneville told reporters Monday morning that the MBTA knew early on that a cracked front axle, which had been in operation since 1

992, on the third car on the Red Line train made it take care of the rails just outside the JFK / UMass station in June. The news service asked in early July for a broken axle on the saved train set; At that time, T officials only said that the agency was still working to determine the cause of the derailment. When investigators tried to pinpoint exactly how the shaft was damaged – and how it was damaged after its ultrasound inspection in mid-2017 – showed no problems – they discovered another problem with the soil brush unit. The brush receives power from the motor and transfers it to a ring wrapped around the shaft, which then guides it through the wheels and into the rails. A working ring is made of smooth, clean steel, sealed from the surroundings to prevent it from being worn. But the ring next to the broken shaft was covered in pits and scrubs, disrupting the clean electrical connection and sending what Gonneville liked to lightning on a smaller scale over the pants. How accurate the ring was to be so corroded remains unclear, Gonneville said. A preventive maintenance inspection in December 2018, conducted approximately every three months, noted that the assembly itself lacked the cover that keeps it sealed. But workers at the time did not look carefully at the rings to check for any damage, so residues from traces of grease to dust had months to come in and tear the quality of the connection. Another inspection in May 2019, just one month before the derailment, reported that two different brush parts were being replaced on the train as derailed, but no staff caught the damage to the ring itself. As a result, the electric arc continued, carrying the shaft in the process. Gonneville emphasized that there are no other immediate risks to the system for similar reasons. The crews conducted ultrasound inspections of the entire Red Line fleet following the derailment and pulled the seven shafts flag for potential service problems, and two bakers demonstrating even the onset of damage were also replaced. "There are no other shafts out there showing any cracks or cracks that begin to propagate," he said. Red Line cyclists experienced significant service effects in the wake of the derailment, as the train slid off the tracks, damaging two buildings that signaled infrastructure and destroyed a third. For months, crews had to direct trains by hand, a slower process than automated signals. Repairs are complete on most of the system, Gonneville said Monday, with the Ashmont line returning to fully automatic signals last week. A short stretch from JFK to Tenean Beach – about halfway to the next station on the Braintree line – is still routed by hand, but Gonneville said the service should be back by mid-late October or sooner.

The train reached that condition as a result of holes in the inspection plans and lost warning signs, investigators found. While axle damage sometimes occurs on heavily used vehicles, the train in question was a few weeks away from a semi-annual inspection that would have detected it.

Crews who conducted preventive inspections about every three months had also not checked the ground, a related part that helps keep the train electrically grounded, which was damaged and caused the shaft to become brittle.

MBTA Deputy Director Jeff Gonnville said that the transit authority had no records of any previous incident with the foundation ring.

In the future, the MBTA will work to prevent the problems from arising again. Ultrasound inspections will now be conducted annually instead of every two years, and regular inspections will include careful examination of the earthing unit for any damage that may occur to the shaft or other parts.

"We have affected a lot of people on the red line in recent months," Gonneville told reporters at a Monday briefing. "It's our duty to make sure this doesn't happen again."

Gonneville told reporters Monday morning that the MBTA knew early on that a cracked front axle, which had been in operation since 1992, on the third car of the Red Line train caused it to groom the rails just outside the JFK / UMass station in June.

The news service inquired in early July about a broken axle on the derailed train set; At that time, T officials only said that the agency was still working to determine the cause of the derailment.

As investigators tried to pinpoint exactly how the shaft was damaged – and how it sustained damage after its mid-2017 ultrasound inspection showed no problems – they discovered another problem with the soil brush unit.

The brush receives power from the motor and transfers it to a ring wrapped around the shaft, which then guides it through the wheels and into the rails. A working ring is made of smooth, clean steel, sealed from the surroundings to prevent it from being worn.

But the ring next to the broken shaft was covered with pits and scrubs, interrupting the clean electrical connection and sending what Gonneville liked to lighten to a smaller scale over the shaft.

How accurate the ring was to be so corroded remains unclear, Gonneville said. A preventive maintenance inspection in December 2018, conducted approximately every three months, noted that the assembly itself lacked the cover that keeps it sealed.

But workers at that time did not look carefully at the rings to check for any damage, so debris from trace fat to dust had months to come in and tear the quality of the connection.

Another inspection in May 2019, just one month before the derailment, reported that two different brush parts were replaced on the train as derailed, but no employees sustained any damage to the ring itself.

As a result, the electric arc continued, shaking the shaft in the process.

Gonneville emphasized that there are no other immediate risks to the system for similar reasons. Crews conducted ultrasound inspections of the entire Red Line fleet following the derailment and pulled seven shafts that were flagged for potential service problems, and two bakers demonstrating even the onset of damage were also replaced.

"There is no other shaft out there showing cracks or cracks beginning to propagate," he said.

The red line drivers experienced significant service effects in the wake of the derailment because, as the train swerved from the tracks, it damaged two buildings that signaled infrastructure and destroyed a third. For months, crews had to direct trains by hand, a slower process than automated signals.

Repairs are complete on most of the system, Gonneville said Monday, with the Ashmont line returning to fully automatic signals last week. A short stretch from JFK to Tenean Beach – about halfway to the next station on the Braintree line – is still routed by hand, but Gonneville said the service should be back by mid-late October or sooner.


Source link