# RE: Why Fire Hydrants Don't Freeze **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [September 12, 2007, 1:31pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893 "2007-09-12T13:31:08Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![nvisco](https://avatars.discourse-cdn.com/v4/letter/n/5f8ce5/32.png) [@nvisco](https://boards.straightdope.com/u/nvisco)\ **Post date:** [September 12, 2007, 1:31pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/1 "2007-09-12T13:31:08Z")
For what it’s worth… Another interesting point to some is that, because the valve is located so far underground, if a car shears off the hydrant in an accident, water does NOT come shooting up like a fountain (as seen in movies). The hydrant is attached at ground level with what is called a “breakaway flange” - allowing it to come free in an accident without damaging the underground structures. In rare cases, the impact of a car can cause damage below ground, including cracking the water supply pipe. However, the water would still not “fountain” up - it would look more like a bubbling pool at the surface. ---
**Author:** ![Uncommon\_Sense](https://avatars.discourse-cdn.com/v4/letter/u/f9ae1b/32.png) [@Uncommon\_Sense](https://boards.straightdope.com/u/Uncommon_Sense)\ **Post date:** [September 12, 2007, 1:39pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/2 "2007-09-12T13:39:00Z")
unless the lower valve was left open and the hose attachment point was closed. ---
**Author:** ![DSYoungEsq](https://avatars.discourse-cdn.com/v4/letter/d/c6cbf5/32.png) [@DSYoungEsq](https://boards.straightdope.com/u/DSYoungEsq)\ **Post date:** [September 12, 2007, 3:06pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/3 "2007-09-12T15:06:56Z")
link? (I can’t, because I don’t get the email, so I don’t see this one, yet) unless it’s an old one I don’t recognize… ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [September 12, 2007, 3:35pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/4 "2007-09-12T15:35:07Z")
I’m guessing this is the article being referenced: [http://www.straightdope.com/mailbag/mhydrant.html](http://www.straightdope.com/mailbag/mhydrant.html) ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [September 12, 2007, 4:25pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/5 "2007-09-12T16:25:49Z")
[QUOTE=nvisco] For what it’s worth… Another interesting point to some is that, because the valve is located so far underground, if a car shears off the hydrant in an accident, water does NOT come shooting up like a fountain (as seen in movies). [/QUOTE] I think that would depend on where you live. here in sunny Southern California, I can tell you for a fact that a car hitting a fire hydrant causes an impressive amount of water to spray into the air. I have personally seen this several times over my life time. ---
**Author:** ![danceswithcats](https://avatars.discourse-cdn.com/v4/letter/d/9e8a1a/32.png) [@danceswithcats](https://boards.straightdope.com/u/danceswithcats)\ **Post date:** [September 12, 2007, 4:32pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/6 "2007-09-12T16:32:28Z")
[QUOTE=Uncommon Sense] unless the lower valve was left open and the hose attachment point was closed. [/QUOTE] Except that no one in the fire service does that. The valve is closed to permit removal of the hose(es) which were attached, and then the caps are reinstalled. We don’t crank the caps down like head bolts, nor are there gaskets within. Although not everybody remembers to do it every time, when I went through training 30+ years ago, we were instructed to observe the column of water inside the hydrant barrel. A properly functioning hydrant, when wound closed, also opens a drain beneath and the standing column is observed to verify that it recedes. If it doesn’t, there’s a problem with the hydrant, and it was reported to Public Works. ---
**Author:** ![Uncommon\_Sense](https://avatars.discourse-cdn.com/v4/letter/u/f9ae1b/32.png) [@Uncommon\_Sense](https://boards.straightdope.com/u/Uncommon_Sense)\ **Post date:** [September 12, 2007, 5:22pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/7 "2007-09-12T17:22:13Z")
[QUOTE=danceswithcats] Except that no one in the fire service does that. [/QUOTE] I know you guys wouldn’t, but I could. I’ve got a wrench right here. _holds up fire-plug wrench_ 😃 ---
**Author:** ![VunderBob](https://avatars.discourse-cdn.com/v4/letter/v/839c29/32.png) [@VunderBob](https://boards.straightdope.com/u/VunderBob)\ **Post date:** [September 12, 2007, 7:08pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/8 "2007-09-12T19:08:50Z")
[QUOTE=danceswithcats] Except that no one in the fire service does that. The valve is closed to permit removal of the hose(es) which were attached, and then the caps are reinstalled. We don’t crank the caps down like head bolts, nor are there gaskets within. Although not everybody remembers to do it every time, when I went through training 30+ years ago, we were instructed to observe the column of water inside the hydrant barrel. A properly functioning hydrant, when wound closed, also opens a drain beneath and the standing column is observed to verify that it recedes. If it doesn’t, there’s a problem with the hydrant, and it was reported to Public Works. [/QUOTE] I have, but it was because of a failure. We were flushing hydrants one night, and broke the valve on one while it was open. We had to call the water department guy to shut off the main, let the flow stop, and then we capped the hydrant, and the WDG turned the main back on. It was that, or lose the use of a gate valve until the water department came around to replace the hydrant. When I did the inspection 5 months later, that hydrant was still on and capped. I officially put it out of service, and I still don’t know if it was fixed. It’s a poor county I live in… I sure as hell would not want to be within 100’ of the thing if someone tried to uncap the thing under pressure, but I doubt that it would be possible anyway. ---
**Author:** ![Uncommon\_Sense](https://avatars.discourse-cdn.com/v4/letter/u/f9ae1b/32.png) [@Uncommon\_Sense](https://boards.straightdope.com/u/Uncommon_Sense)\ **Post date:** [September 13, 2007, 1:09pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/9 "2007-09-13T13:09:00Z")
[QUOTE=VunderBob] I sure as hell would not want to be within 100’ of the thing if someone tried to uncap the thing under pressure, but I doubt that it would be possible anyway. [/QUOTE] You aint kiddin. We emptied 80,000 gallons of water out of the city water tower when we hit a main while attempting to bore under a city street. Lifted the road up 6" and there was water _everywhere_ coming out of _every_ crack in the road up and down several blocks. Lots of pressure there! ---
**Author:** ![Kalhoun](https://avatars.discourse-cdn.com/v4/letter/k/3bc359/32.png) [@Kalhoun](https://boards.straightdope.com/u/Kalhoun)\ **Post date:** [September 16, 2007, 10:29pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/10 "2007-09-16T22:29:57Z")
Fire hydrants DO freeze. At least, in Chicago they do. Maybe someone tampered with it or it was improperly installed or whatever, but they freeze. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [September 17, 2007, 12:13am UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/11 "2007-09-17T00:13:49Z")
[QUOTE=Kalhoun] Fire hydrants DO freeze. At least, in Chicago they do. Maybe someone tampered with it or it was improperly installed or whatever, but they freeze. [/QUOTE] I don’t think so. I’m unable to find a single instance of a hydrant freezing anywhere in the lower 48 states. You have a cite for this? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [September 17, 2007, 12:19am UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/12 "2007-09-17T00:19:30Z")
Ah, persistence pays off: [I stand corrected](http://abclocal.go.com/wls/story?section=News&id=163373). ---
**Author:** ![Kalhoun](https://avatars.discourse-cdn.com/v4/letter/k/3bc359/32.png) [@Kalhoun](https://boards.straightdope.com/u/Kalhoun)\ **Post date:** [September 17, 2007, 12:29am UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/13 "2007-09-17T00:29:13Z")
[QUOTE=Q.E.D.] Ah, persistence pays off: [I stand corrected](http://abclocal.go.com/wls/story?section=News&id=163373). [/QUOTE] Thanks for doing the legwork for me! ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [September 17, 2007, 12:34am UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/14 "2007-09-17T00:34:05Z")
😃 And I must say, I’m surprised. I’ve never heard of this happening before. ---
**Author:** ![Kalhoun](https://avatars.discourse-cdn.com/v4/letter/k/3bc359/32.png) [@Kalhoun](https://boards.straightdope.com/u/Kalhoun)\ **Post date:** [September 17, 2007, 12:34am UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/15 "2007-09-17T00:34:54Z")
[QUOTE=Q.E.D.] 😃 And I must say, I’m surprised. I’ve never heard of this happening before. [/QUOTE] Actually, a quick Google found frozen hydrants in Ohio and Michigan, as well. I think it’s fairly common. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [September 17, 2007, 3:21am UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/16 "2007-09-17T03:21:43Z")
[QUOTE=Q.E.D.] 😃 And I must say, I’m surprised. I’ve never heard of this happening before. [/QUOTE] I’m not surprised, especially after hearing of the origins of Chicago. The origins of Chicago? Well there was a bunch of New Yorkers talking one day, and one of them says “I love the crime, I like the overcrowding, but it just isn’t cold enough here.” ---
**Author:** ![Elendil\_s\_Heir](https://avatars.discourse-cdn.com/v4/letter/e/7cd45c/32.png) [@Elendil\_s\_Heir](https://boards.straightdope.com/u/Elendil_s_Heir)\ **Post date:** [September 18, 2007, 1:18pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/17 "2007-09-18T13:18:57Z")
[QUOTE=Rick] …The origins of Chicago? Well there was a bunch of New Yorkers talking one day, and one of them says “I love the crime, I like the overcrowding, but it just isn’t cold enough here.” [/QUOTE] Another added, “Yeah, and it’s not _nearly_ windy enough.” How are hydrants unfrozen in an emergency like that described in **Q.E.D.**'s link? Blowtorches? ---
**Author:** ![RedSwinglineOne](https://avatars.discourse-cdn.com/v4/letter/r/a9adbd/32.png) [@RedSwinglineOne](https://boards.straightdope.com/u/RedSwinglineOne)\ **Post date:** [September 18, 2007, 3:43pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/18 "2007-09-18T15:43:46Z")
[QUOTE=nvisco] For what it’s worth… Another interesting point to some is that, because the valve is located so far underground, if a car shears off the hydrant in an accident, water does NOT come shooting up like a fountain (as seen in movies). [/QUOTE] It happens in California. I’ve seen it here in Sunnyvale, and [here are some photos](http://sfist.com/2007/08/27/18th_streetguer.php) of it happening in San Francisco. ---
**Author:** ![Uncommon\_Sense](https://avatars.discourse-cdn.com/v4/letter/u/f9ae1b/32.png) [@Uncommon\_Sense](https://boards.straightdope.com/u/Uncommon_Sense)\ **Post date:** [September 18, 2007, 4:51pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/19 "2007-09-18T16:51:35Z")
[QUOTE=Elendil’s Heir] Another added, “Yeah, and it’s not _nearly_ windy enough.” How are hydrants unfrozen in an emergency like that described in **Q.E.D.**'s link? Blowtorches? [/QUOTE] No, they grab the next one- half a block down. ---
**Author:** ![UncleRojelio](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/unclerojelio/32/3160_2.png) [@UncleRojelio](https://boards.straightdope.com/u/UncleRojelio)\ **Post date:** [September 18, 2007, 7:05pm UTC](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893/20 "2007-09-18T19:05:07Z")
[QUOTE=Q.E.D.] Ah, persistence pays off: [I stand corrected](http://abclocal.go.com/wls/story?section=News&id=163373). [/QUOTE] But were the hydrants frozen, as in the cap is off and the valve open but nothing comes out, or were they merely iced over and inaccessible? [Next page](https://boards.straightdope.com/t/re-why-fire-hydrants-dont-freeze/418893.md?page=2)