Monthly Archives: June 2013

Duluth, MN – 4 small children, 1 woman injured in escalator pileup

by peter | 1 Comment

Four young children and woman suffered injuries on Wednesday, June 26, 2013, around 1:05 p.m., after an escalator accident occurred at the Wells Fargo building in downtown Duluth, Minnesota. According to local news reports, a group of 20 children and their daycare providers boarded the escalator traveling downwards. One of the children was apparently afraid to step off the escalator, creating a pileup behind them. Further complicating the situation, the children were apparently tied together or otherwise connected to a rope, causing a “chain reaction” when the pileup began. One of the children suffered a severe ankle injury; the remaining four were treated for minor cuts and bruises.

Remember to step off immediately when reaching the end of an escalator. Never let feet “slide off” the end of an escalator; step over the comb teeth, and move away from the end of an escalator so that others behind you have room to exit.

Sources reporting this story include:

Shanghai, China – Woman killed by runaway shopping cart on inclined moving walkway

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A 60-year old grandmother died Friday, June 21, 2013, after a runaway shopping cart struck her at high speed while she was riding an inclined moving walkway at the Lianhua supermarket in the Jiading district of Shanghai, China. Surveillance video of the incident depicts the victim calmly disembarking the moving walk and turning around in the split second before the runaway shopping cart struck her fatally, suggesting that the victim heard the cart careening out of control, even though it was too late for her to get out of the cart’s path. According to the report by STOMP, a Singapore news agency, the runaway cart belonged to two men who had loaded it with 15 crates of drinks, estimated to have weighed 330 pounds (150kg), who boarded the moving walkway moments before losing control of the cart. The victim was reportedly thrown almost 20 feet (6 meters) from the point of impact. She was transported to a nearby hospital but succumbed to her injuries. Local police are investigating the incident.

While somewhat uncommon in the United States, inclined moving walkways are often used in airports and supermarkets to transport people between floors with the capacity of an escalator and the convenience of an elevator (namely, that people can take along their suitcase, shopping cart, or baby carriage). Typically, the carts at locations with inclined moving walks will remain under control using an automatic brake that is applied when the cart handle is released, or via strong magnets in the cart wheels that stay adhered to the ramp surface. However in this case, the recklessness of the two patrons to use their own cart, which they also overloaded, apparently led to this woman’s untimely death.

Also of note is that the surveillance video depicts that the moving walks in this incident were continuously sloped. In the United States, moving walkway treadways are limited to inclines of 12 degrees at any point, and 3 degrees within 3 feet of the landing. Had the slope tapered at the bottom landing, it might have provided the victim an additional split second to avoid the careening cart. However, clearly in this case the reckless loading of an unsafe cart appears to be the prevailing causative factor.

Sources reporting this story include:

New Delhi, Delhi, India – Nine people injured after apartment building falls one floor

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Nine people suffered minor injuries around 2:50 p.m. local time, June 18, 2013, when an elevator in an apartment building in New Delhi, Delhi, India apparently “slipped” one floor, falling from the fourth floor before stopping suddenly at the third floor. The victims were all taken to a nearby hospital, where they received first aid and were released. No information was available regarding the cause of the malfunction.

Based on the the description of the incident, it appears that the elevator may have descended uncontrollably, causing the elevator to overspeed downwards, causing the overspeed governor to apply the car safety. Typically, when an elevator exceeds its rated speed, the overspeed governor will first trip electrically, sending a signal to the elevator controller to stop the car. If the controller is unable to stop the car and the car continues to accelerate downward, it will then trip mechanically. When the governor trips mechanically, jaws on the centrifugal governor grab the governor cable. The energy of the descending car then causes the governor cable, which is now fixed, to engage the car’s emergency brakes, which clamp down on the guide rails, stopping the car.

In the United States, the ASME A17.1 “Safety Code for Elevators and Escalators” provides that when the overspeed governor trips mechanically, the car should not decelerate at a rate greater than “1 G”, the rate of normal gravitational acceleration, or 9.8 meters per second-squared. It should be noted that a downward acceleration of “1 G” would cause an elevator rider to experience a relative weight twice their normal weight. That is, a passenger would “weigh” twice their normal weight relative to the elevator floor below their feet, so it is not difficult to understand how a passenger would be thrown around and injured when an elevator stops during a high speed mechanical safety application. However, had the mechanical safety not been provided or malfunctioned, the elevator would have continued to decelerate until it reached terminal velocity and crashed into the pit at the bottom landing, so despite that these passengers suffered minor injuries, they should consider themselves lucky that the safety devices worked as designed, allowing them to escape potentially fatal injuries.

Sources reporting this story locally include:

Santa Clara, CA – Seasoned elevator mechanic struck, killed by counterweight at Levi’s Stadium

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On Tuesday, June 11, 2013, around 6:45 a.m., seasoned elevator mechanic Donald White, 63, a 43-year industry veteran, was struck and killed by a counterweight while working on a ladder in an elevator pit. The elevator was being constructed by Schindler at the San Francisco 49ers’ new stadium, Levi’s Stadium, a $1.3 billion project expected to be completed in 2014. Cal/OSHA is investigating the accident and expects to have a completed report in approximately six months. It was not immediately clear what caused the counterweight to move while Mr. White was in the pit. This is the first major incident reported so far during the stadium’s construction.

Elevator accidents involving counterweights generally involve elevator personnel, as in this case, although we have documented at least two other recent cases involving non-elevator personnel that entered the elevator pit to clean the pit and to retrieve dropped keys. Besides counterweight collisions in the pit, elevator mechanics and inspectors can be struck by the counterweight as the car and the counterweight pass each other halfway up the hoistway. Working with a ladder in a pit is especially dangerous as it will reduce or eliminate available refuge space while also potentially introducing a foreign object into that space.

Sources reporting this incident include: