# Is ice dropping off large bridges a common hazard in winter weather?

**URL:** <https://boards.straightdope.com/t/is-ice-dropping-off-large-bridges-a-common-hazard-in-winter-weather/644972>\
**Category:** Factual Questions\
**Created:** [December 24, 2012, 1:45am UTC](https://boards.straightdope.com/t/is-ice-dropping-off-large-bridges-a-common-hazard-in-winter-weather/644972 "2012-12-24T01:45:25Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\
**Post date:** [December 24, 2012, 1:45am UTC](https://boards.straightdope.com/t/is-ice-dropping-off-large-bridges-a-common-hazard-in-winter-weather/644972/1 "2012-12-24T01:45:25Z")

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I hadn’t thought of this potential problem before. Large chunks of ice crashing down on cars. Those ice bombs must be falling at least a 100 ft and reaching terminal velocity. That’s not a good thing. 😛

Is it a common problem on winter bridges. For example the Brooklyn Bridge has all those suspension cables. Does the ice break off and crash into cars?

What engineering can be done to prevent it?

[Article:](http://www.dailymail.co.uk/news/article-2252341/The-Port-Mann-Bridge-Worlds-widest-bridge-shut-just-weeks-opening.html)

[Could be a Common Event if not fixed.](http://www.theprovince.com/news/vancouver/Port+Mann+bridge+bombing+could+annual+event+fixed/7734824/story.html)

> [@](#):
>
> When The Port Mann Bridge opened in British Columbia earlier this month, it was supposed to slash commuting times up to an hour.
> 
> But barely three weeks later the bridge has closed down when massive chunks of ice fell off the bridge’s high cables and plummeted onto drivers below - causing injuries and thousands of dollars worth of damage.
> 
> At ten lanes, the bridge is the widest in the world and the second longest in North America.
> 
> But outraged drivers are saying they’d rather have a leaner bridge without the hazards.

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**Author:** ![Captain\_Morgan](https://avatars.discourse-cdn.com/v4/letter/c/bc8723/32.png) [@Captain\_Morgan](https://boards.straightdope.com/u/Captain_Morgan)\
**Post date:** [December 24, 2012, 10:58am UTC](https://boards.straightdope.com/t/is-ice-dropping-off-large-bridges-a-common-hazard-in-winter-weather/644972/2 "2012-12-24T10:58:10Z")

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Falling Icicles have closed the Brooklyn Bridge to foot traffic before.

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**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\
**Post date:** [December 24, 2012, 2:33pm UTC](https://boards.straightdope.com/t/is-ice-dropping-off-large-bridges-a-common-hazard-in-winter-weather/644972/3 "2012-12-24T14:33:10Z")

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I noticed the article blamed vibration for shaking off the ice chunks. Weather warms just enough to loosen the ice and then it comes down onto the cars. It could be a difficult engineering problem to fix.

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**Author:** ![bobot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobot/32/21622_2.png) [@bobot](https://boards.straightdope.com/u/bobot)\
**Post date:** [December 24, 2012, 4:50pm UTC](https://boards.straightdope.com/t/is-ice-dropping-off-large-bridges-a-common-hazard-in-winter-weather/644972/4 "2012-12-24T16:50:12Z")

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Ice falling from tall buildings is a hazard, as well.  
Concerning bridges: about 25 years ago a couple of kids were goofing around in my neck of the woods, dropping chunks of concrete from a highway overpass. If my memory serves me, 2 people were pretty much decapitated.