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San Jose Fire had an impossibly complex incident scene (2019)
- pinewurst 5y ago(2019)
- Cyberdog 5y agoAlso, …, not .. or .... (or ... for that matter if you're not using ASCII or something). Yes, this really does bug me.
- rossdavidh 5y agoIf you hit a bus hard enough to knock it over, even given that you were driving an SUV, you were going too fast in town, it seems to me.
- toast0 5y agoI don't see that the bus was knocked over. In the photos, the bus is upright and there was no mention of it tipping. It got pushed off the road, and a power pole was knocked over.
- rossdavidh 5y agoMy mistake, I misread it. Although, if you're going fast enough to push a bus (an extra-long, bendy bus at that) off the road, it still seems like you were going rather fast for in town?
- sandworm101 5y agoEach accident is different. The wreckage of the SUV doesn't look like it hit all that hard. It struck the left front corner of the bus. In doing so it may have pushed the wheel, or caused the driver/steering wheel to move sideways. Either could cause the bus to briefly drive itself off the road more so than being directly pushed by the SUV. The bus does seem to have been moving at the time of impact.
- jhayward 5y agoIt is pretty common in HGV accidents that a blow against one of the steer tires will break the steering on that side and result in loss of control.
- deleted 5y ago[deleted]
- LatteLazy 5y agoThat depends, batteries on top might make it top heavy and much more likely to roll over...
- Symbiote 5y agoPresumably the buses still have to pass the "tilt test", even with the batteries. (Are there more batteries underneath?) [2] says single deck buses in Hong Kong must be able to tilt 35° without tipping. [1] https://www.millbrook.co.uk/services/vehicle-and-component/dynamics-and-performance/vehicle-tilt-testing/ https://www.millbrook.co.uk/services/vehicle-and-component/d... [2] https://en.wikipedia.org/wiki/Tilt_test_(vehicle_safety_test) https://en.wikipedia.org/wiki/Tilt_test_(vehicle_safety_test...
- LatteLazy 5y agoI can't find a tilt test standard for the USA. Im assuming there is one...
- sandworm101 5y agoThere isn't: https://www.ntea.com/NTEA/NTEA/Member_benefits/Technical_resources/FMVSSguide/FederalMotorVehicleSafetyStandardsFMVSSGuide.aspx https://www.ntea.com/NTEA/NTEA/Member_benefits/Technical_res...
- 14 5y agoI just saw a video of a man who was rescued by police from a burning vehicle. He suffered a medical incident while back his truck up and ended up flooring the gas as he got into his parking spot. The tires spun high speed while the truck stood still until they caught fire and almost burned him alive. He did suffer smoke inhalation but I believe made it. It could have been the bus driver attempting to make evasive maneuvers added to the fact the car hit it as well could be why it ended up a bit farther off the road then expected.
- tomc1985 5y agoDon't worry, the SUV driver is going to get what's coming to them from the government
- andyxor 5y agoMicroservices in action
- deleted 5y ago[deleted]
- jcims 5y agoAbsolutely amazing nobody was killed. I wonder what the conversation was like on the bus keeping folks in while there was fire encroaching. Even if you don't touch the conductors, potential gradient can ruin your day.
- dehrmann 5y agoIs there a right technique for hopping (literally) out of bus like that?
- 14 5y agoWe learned as kids stay put unless absolutely having to leave the vehicle. If you had to leave because of say a fire you were to keep both feet together and literally hop away like you say not walk. This is going way back it seems to make sense but I haven’t checked the source on this.
- admax88q 5y agoShuffling is recommended over hopping because you're less likely to fall over. Shuffle in small movements keeping your feet on the ground and close together.
- Thorrez 5y agoWhere did you learn this? Were they specifically teaching you want to do if a power line lands on your car? That seems like a pretty rare situation. Or was it about electric cars or busses?
- deleted 5y ago[deleted]
- poopsmithe 5y agoIs there a version of this that doesn't require a FB account?
- yojo 5y agoIt's mostly text, though there are some pictures at the end. Here you go: Bruce Dembecki August 12, 2019 San Jose Fire had an impossibly complex incident scene that will be the subject of countless Battalion Chief exams in the future... An SUV collided with a large bendy bus, pushing the bus off the road and into a high voltage power pole, which came down on top of the bus. Power lines are down across the bus and the SUV, and the streets. At the fire station next door there is a large bang and the power goes out... crews looking to find out what happened discovered they couldn’t open the apparatus bay doors... Switching to manual mode the doors at the fire station are opened, but they discover they can’t get their equipment out because the power lines are across the apron of the fire station. Manually open the back doors... the electric gate at the rear of the station is closed... plans for power loss at the station involve manually exiting through the front of the apparatus bay, time was lost as crews figured out how to open the back gate... Meanwhile the 11 people on the bus can’t leave the bus because of the power lines... but the SUV has burst into flames, and the fire is spreading to the bus... passengers can’t stay on the bus because of the fire... they can’t get off because of the electricity... Power remains a problem and fire crews are able to get a 1.5” line on the SUV from 30’ away... the SUV fuel tank starts dripping, the fuel ignites... the water stream from 30’ away pushes the burning fuel under the SUV... to the bus... The bus is a diesel electric hybrid with 900V batteries on the roof, smashed from above by the power pole, being attacked from below by fire... fire crews can not fight the bus fire until a bus mechanic arrives with information on how deal with the batteries... the bus mechanic arrives, but can’t go near the bus until PG&E neutralizes the power from their lines... Somehow, everyone was removed from the bus and there were no serious injuries. Hours later the major traffic artery remains completely closed as PGE deals with the power... when they are done fire will look at the bus and the hazmat team will analyze the damage to the bus electrical storage systems... eventually the bus and SUV will be removed and the scene turned over to PG&E to repair the power system before the road can be reopened... Elapsed time 4:03:00 and counting, we still can’t get at the battery systems on the bus... It’s going to be a long afternoon - did I mention it’s 98 degrees outside?
- deleted 5y ago[deleted]
- chrisfosterelli 5y agoI don't know anything about urban fire fighting. It seems like the primary block to rescuing the civilians is that the power is still on, and they had to wait for the power to be off. That makes me think that firefighters, if they can't already, should be able to either 1) turn off power on site, or 2) easily contact someone who can do so remotely.
- davidbanham 5y agoWe can easily contact someone but they can’t do it remotely. The power company needs to come on scene. Isolating power is a lot more complex than it used to be because of solar installations. We can never be sure that every building’s solar is properly isolated from the grid. In these cases where people need to be evacuated from a vehicle that’s live due to power lines there are protocols for doing so, it’s just more risky. We need to ensure they jump from the vehicle so they’re never touching the vehicle and the ground simultaneously. We also need to get them to shuffle to make sure there’s no step potential between their feet. Neither is easy to guarantee with a member of the public probably panicking.
- chrisfosterelli 5y agoVery interesting. I hadn't considered the challenges solar could introduce to isolating power. Thanks for the answer.
- ljm 5y agoThere's a similar problem with people using male-to-male cords (suicide cords) on their generators too? Plug a portable generator into your house this way and now it's pumping out electricity and not purely consuming it.
- LeifCarrotson 5y agoIt should be obvious that before you do so you should turn off the main disconnect. Otherwise you're electrifying the line for utility workers and also powering (half of) your neighbor's house backwards through a 20A circuit from your little generator, which won't work out well...
- neolog 5y agoI don't see why they can't just walk out the front door of the bus. No power lines are near it.
- FPGAhacker 5y agoIt’s generally not a good idea to close a high power, high voltage circuit with a live human.
- dredmorbius 5y agoThere's the risk of grounding from the vehicle to earth by a disbarking passenger, as well as of ground currents within 100m or so of a high-voltage downed line. Mitigating those conditions requires specific actions and measures. Ensuring compliance by all passengers aboard the bus is a challenge. The lesser risk might be having them remain aboard. Even the option of carrying or assisting passengers from the bus could risk grounding. Consider that passengers might be old, young, handicapped, non-English speakers, or otherwise have difficulty understanding or complying with instructions.
- AlbertCory 5y agoI just walked past a SJ fire station with my dog yesterday, and had a nice visit with a firefighter sitting outside. I'll have to ask them about this next time I see one. This station doesn't have a backdoor, I don't think.
- chrisseaton 5y agoWhy are these local power lines up in the air on such low poles? Shouldn't they be buried when in an urban environment? I've only ever seen power lines up in the air when crossing open country, and then 50m or so up in the air.
- jdavis703 5y agoThis is fairly common across the US (based on your use of the metric system I’m guessing you’re not familiar with US cities.) About the only areas with buried lines are high-density urban neighborhoods and wealthy suburbs.
- barsonme 5y agoSome places on the coasts bury them as well. My wife grew up on the coast and it wasn’t uncommon to go a few days or more without power each year because wind storms would knock over trees onto the power lines. They’ve since buried a lot of their lines.
- adventured 5y agoIt's not unusual for rural and suburban neighborhoods built since the 1970s to bury their powerlines. Even in nowhere Appalachia where I grew up that was very normal.
- mcast 5y agoMany of them in Florida on the east coast are also buried to lessen hurricane damage to infrastructure, but of course the main arteries coming from the power plants are always above ground.
- koheripbal 5y agoEven most wealthy suburbs have them above ground. It is just way cheaper to install, insulate, and maintain.
- thirtyseven 5y agoMy understanding is that it's only economical to bury utility lines when there is frequent enough inclement weather to bring them down, which definitely isn't the case in San Jose.
- secondcoming 5y ago> Switching to manual mode the doors at the fire station are opened, but they discover they can’t get their equipment out because the power lines are across the apron of the fire station. Why couldn't the fire trucks just drive over the wires? They'd be insulated, no?
- kelnos 5y agoIsn't an "apron" in this case an overhead structure? They might have been worried about the power lines touching the top or sides of the truck, or getting tangled and making the situation worse.
- toast0 5y agoApron in this case is more or less the driveway, I believe. From the photos (and expectations from living in Santa Clara county for several years), there is no overhead structure outside fire department buildings. From what I can tell, the fire engines couldn't go out the front, because the wires were hanging down over their driveway and they didn't want to strike them on their way out.
- mthoms 5y agoThe apron is just the asphalt ("tarmac" for the British) area in front of the station.
- deleted 5y ago[deleted]
- gmueckl 5y agoThat depends entirely on the voltage in the wires. A proper high voltage line could draw an arc to the wheel and chassis if they get close enough (less than a meter can be enough). The people in the cabin should still be protected by the Faraday effect. But anything outside that cage or close by may be effected - it's almost impossible to predict which way the currents would flow.
- the__alchemist 5y ago
- topkai22 5y agoQuestion that sprung to mind, especially with the Dixie fire continue to rage- how did PG&E not know there was something seriously wrong with their equipment and shut off power remotely? That’s an honest question- the electrical system is big, complex, and often was built before I was born, but it seems like that sort of failure is something that would show up on a sensor somewhere.
- deleted 5y ago[deleted]
- perryizgr8 5y agoIs it not possible to design power lines in such a way that voltage is cut off automatically in case they touch the ground or some other object? You can check for arcing or abnormal spikes in current. Or loss of voltage on the other end. Should be easy to do on the ends of the line, at the sub station.
- breakfastduck 5y agoAh but how do you know where the fault has occured? Do you turn off power for an entire neighbourhood?
- thehappypm 5y agoSounds easy, but one false positive causing a blackout would be brutal for trust in the system.
- neonate 5y agohttps://archive.md/V8CIj https://archive.md/V8CIj