4 ms·

AvE on youtube came to the same conclusion 2 weeks ago: https://www.youtube.com/watch?v=cexN2-T6dxY https://www.youtube.com/watch?v=cexN2-T6dxY And a follow-up

AvE on youtube came to the same conclusion 2 weeks ago: https://www.youtube.com/watch?v=cexN2-T6dxY https://www.youtube.com/watch?v=cexN2-T6dxY And a follow-up after new pictures became available further confirms this: https://www.youtube.com/watch?v=7Wo7J_buZUE https://www.youtube.com/watch?v=7Wo7J_buZUE The article makes it seem like it's a common practice in the industry. Pretty scary! I don't really understand how it saves time, though... I'd think the bottleneck is the heavy-lift crane, isn't it?

a2tech 7y ago
In the AvE comments there's a lot of people claiming that this is NOT a common practice--because its incredibly dangerous. It just takes a gust of wind when those pins are out to cause massive damage.
- kurthr 7y ago
  Except now somebody's boss is going to site this article to show it's common practice (I'm only partially kidding) or only remember the removing pins saving time part. I'm reminded of the LA TV news shorts reminding people not to modify their lighters to continuously spew flame and throw them out the window on the freeway. The alignment of stupidity and (anti)social incentives to risk other people's lives is a dangeous thing. Antivax rallies come to mind.
HissingMachine 7y ago
It's not hard to imagine that the practice is common. I know I'm cutting corners and don't know anything about construction, but if you make a little mental game out of it. If you have 20 men on site, dismantling crane probably shuts down most of the work on site, so you have to send most of the 20 men home during dismantling. You hire an outside contractor to dismantle the crane, so you probably want it to only take a day to cut costs on outsourcing and worker leave, you bring the dismantling crew in the morning to remove the pins and the lift the pieces off on the afternoon. There are thousands of cranes all over the world and there are probably dozens erected and dismantled daily. If we only have a disaster every couple of years, out of the hundreds of operations, that's when the practice get's exposed, it's like lottery but you win every time if you don't happen to hold the winning ticket. Truth of it is, many of us roll the dice with those odds.
Someone 7y ago
Disclaimer: I know almost nothing about this business. I do think the following could be a good explanation: If removing a bolt takes 2 minutes and moving from corner to corner (at height, carrying a power tool capable of unbolting the bolts) another 2, you can gain 2x8+3x2=22 minutes per section removed by removing the bolts before the dismantling crane is attached to the part. Multiply by 6 or so on a day, and you can go home two hours earlier (or pay all personnel involved for two fewer hours), and (possibly the most important factor) rent that heavy-lifting crane for two fewer hours. Also, you probably are right that the heavy-lift crane takes more time to do its work than removing the bolts. If so, the workers who loosen the bolts are mostly waiting, but they are still being paid. If removing a fully tightened bolt takes more than one person (say because the tool used to do so is big and heavy; these bolts probably are inches in diameter), while removing a loosened one can be done by one, it also pays to have two persons loosen all bolts in the morning, send one home (or to another job) and only pay one in the afternoon to remove the loosened bolts.

a2tech 7y ago

In the AvE comments there's a lot of people claiming that this is NOT a common practice--because its incredibly dangerous. It just takes a gust of wind when those pins are out to cause massive damage.

kurthr 7y ago
Except now somebody's boss is going to site this article to show it's common practice (I'm only partially kidding) or only remember the removing pins saving time part. I'm reminded of the LA TV news shorts reminding people not to modify their lighters to continuously spew flame and throw them out the window on the freeway. The alignment of stupidity and (anti)social incentives to risk other people's lives is a dangeous thing. Antivax rallies come to mind.

HissingMachine 7y ago

It's not hard to imagine that the practice is common. I know I'm cutting corners and don't know anything about construction, but if you make a little mental game out of it. If you have 20 men on site, dismantling crane probably shuts down most of the work on site, so you have to send most of the 20 men home during dismantling. You hire an outside contractor to dismantle the crane, so you probably want it to only take a day to cut costs on outsourcing and worker leave, you bring the dismantling crew in the morning to remove the pins and the lift the pieces off on the afternoon. There are thousands of cranes all over the world and there are probably dozens erected and dismantled daily. If we only have a disaster every couple of years, out of the hundreds of operations, that's when the practice get's exposed, it's like lottery but you win every time if you don't happen to hold the winning ticket. Truth of it is, many of us roll the dice with those odds.

Someone 7y ago

Disclaimer: I know almost nothing about this business. I do think the following could be a good explanation: If removing a bolt takes 2 minutes and moving from corner to corner (at height, carrying a power tool capable of unbolting the bolts) another 2, you can gain 2x8+3x2=22 minutes per section removed by removing the bolts before the dismantling crane is attached to the part. Multiply by 6 or so on a day, and you can go home two hours earlier (or pay all personnel involved for two fewer hours), and (possibly the most important factor) rent that heavy-lifting crane for two fewer hours. Also, you probably are right that the heavy-lift crane takes more time to do its work than removing the bolts. If so, the workers who loosen the bolts are mostly waiting, but they are still being paid. If removing a fully tightened bolt takes more than one person (say because the tool used to do so is big and heavy; these bolts probably are inches in diameter), while removing a loosened one can be done by one, it also pays to have two persons loosen all bolts in the morning, send one home (or to another job) and only pay one in the afternoon to remove the loosened bolts.