fire hydrant question

[Alpo]

A fire hydrant is basically like a water faucet on a house, right? It's got an area that you connect the hose to, and it's got a thing that you unscrew so the water can come out.

 

I've read for years about little kids in big cities - New york, Philadelphia, like that - opening the thing, and using a wrench made of two scraps of wood and two pieces of wire, unscrewing the nut on the top so water comes shooshting out and they can play in the water in the hot summer.

 

I was just watching a video clip about a television show about the Chicago fire Department. In this clip people were stealing fire hydrants, and selling them to scrap yards. There's a fire, and the fireman run over to attach the hose to the hydrant, and there's a base with a big hole in it, but there's no hydrant.

 

They show a YouTube video of how to steal a hydrant. Wrap a chain around it, hook it up to a truck and drive off. Breaks it off clean with the ground.

 

So my question is, when they break the hydrant off, why doesn't water go shooting up out of the pipe?

 

I recall an NCIS episode where Tony swerved to miss a bicycle jaywalker and ran into a fire hydrant and there was a huge fountain of water.

 

It seems like either the Chicago fire Department show or NCIS is wrong. Or maybe both of them.

 

What would happen if you broke a fire hydrant off?

[Brock]

In northern climes there is no water in the hydrant because it will freeze and crack. The nut on the top controls a valve below the frost line. Might be like that in the south too. You want to connect your hoses before you allow water pressure.

[Subdeacon Joe]

 

 

 

[Alpo]

34 minutes ago, Brock said:

In northern climes there is no water in the hydrant because it will freeze and crack. The nut on the top controls a valve below the frost line. Might be like that in the south too. You want to connect your hoses before you allow water pressure.

Did not think about Chicago being way up there where it gets cold.

[Trailrider #896]

Cold or hot fire hydrants are favorites of male dogs! I have two boys and two hydrants within a block of one another. The thing is, both dogs like to use the same hydrant when we are out for a walk! 

[Brock]

2 hours ago, Trailrider #896 said:

Cold or hot fire hydrants are favorites of male dogs! I have two boys and two hydrants within a block of one another. The thing is, both dogs like to use the same hydrant when we are out for a walk! 

P-mail. Checking their messages.

[Alpo]

There's a house down the road. In the front yard they have a tree stump and about 10 ft away from it they have a fire hydrant. The tree stump has a sign on it says COUNTRY DOGS. The fire hydrant has a sign says CITY DOGS.

[watab kid]

here the hydrants are set well bello3  frost line -in our area  the water wo=uld freeze if it were above that level , for at least seven or eight months of the 35 years ive lived here , so the valve is low and yes it takes a wrench to operate ours , but i could do it if i wanted to - what you are speaking or is big city kids opening them in hot times for recreation - yes i believe it happens and yes i think its common in big cities but not here in outstate [as our gov4ernor calls all of us the land of rocks and cows] we are more concerned with fires and we have lakes and ponds to swim in 

[Brock]

How to open a hydrant

 

 

[Rye Miles #13621]

There’s a fire hydrant on the next door tree lawn. They were testing the fire hydrant last week. I watched as they opened it and a burst of brown water came out for a few seconds then It was clear. The main pipe that feeds the hydrants are below the freeze line which is about 5-6 feet down. I’m in a cold climate here in Ohio. It’s reassuring that a fire hydrant is right next to my house. 
 

From AI

A fire hydrant is usually connected directly to a municipal water main. In Ohio, the water main feeding a fire hydrant is commonly buried:

• About 5 to 8 feet below the ground.
• In some locations, it may be as shallow as 4 feet or as deep as 10 feet, depending on local conditions, road construction, and utility standards.

The visible hydrant sits on a vertical pipe called a barrel that extends from the buried water main up to ground level. The valve that controls the hydrant is typically located at the bottom of the hydrant, below the frost line, so water drains out of the hydrant after use and doesn’t freeze in winter.

Edited June 29 by Rye Miles #13621

[Sedalia Dave]

The brown water was from rust in the barrel of the hydrant not the water main.

[Rye Miles #13621]

1 hour ago, Sedalia Dave said:

The brown water was from rust in the barrel of the hydrant not the water main.

Yep, I know that. 

[Michigan Slim]

There is also a weep hole so the hydrant can drain when finished using.

[Linn Keller, SASS 27332, BOLD 103]

Hydrants are supposed to have a breakaway to prevent turning into a geyser if hit by a vehicle or other stressor (including yanked off with chain and truck)
Most of the time it works.

Most of the time.

 

[Michigan Slim]

On 6/29/2026 at 8:28 PM, Linn Keller, SASS 27332, BOLD 103 said:

Hydrants are supposed to have a breakaway to prevent turning into a geyser if hit by a vehicle or other stressor (including yanked off with chain and truck)
Most of the time it works.

Most of the time.

 

Just had an assistant chief find out that they work. Laying line on his own by hooking up and driving away. Hose caught. Thanks buddy, we'll get that for you. 

[J.D. Daily]

In costal CA communities the valve is located in the hydrant.  When a car or truck hits one there is a geyser.  There was a hydrant on the side walk out front of where I worked & businesses across the street one day a truck tractor & trailer was making a delivery to one of these businesses loading dock.  The driver blew it when backing up.  The trailer hit the hydrant and sheared it off.  It took the San Leandro FD more than a half hour to arrive & shut the flow off.   The geyser was  near 100 feet high.  The flood filled the street gutter to the point water was flowing across the sidewalk.

[watab kid]

it takes a wrench with a long handle to turn on a hydrant here the shaft yoyr turning is at least eight foot long the valve is down on the water line below ground and frost line takes a big wrench to fit the valve stem 

[Linn Keller, SASS 27332, BOLD 103]

9 hours ago, Michigan Slim said:

Just had an assistant chief find out that they work. Laying line on his own by hooking up and driving away. Hose caught. Thanks buddy, we'll get that for you. 

I served as fire chief for a term.
Nicknames are earned and they stick like grass stains on new white jeans: a long time member and multi-term Chief was responding to the firehouse and hit ice on a curve.

From that day on was known as "Crash."

(He dented a quarter panel and we drilled, wired, jerked and beat the dent out, finished it out and you couldn't tell, but the nickname still sticks with the man four decades later!)

I wonder what colorful nickname this hydrant-yanker you mentioned, will inherit ... 

[Dubious Don #56333]

On 6/28/2026 at 7:13 AM, Alpo said:

A fire hydrant is basically like a water faucet on a house, right? It's got an area that you connect the hose to, and it's got a thing that you unscrew so the water can come out.

 

I've read for years about little kids in big cities - New york, Philadelphia, like that - opening the thing, and using a wrench made of two scraps of wood and two pieces of wire, unscrewing the nut on the top so water comes shooshting out and they can play in the water in the hot summer.

 

I was just watching a video clip about a television show about the Chicago fire Department. In this clip people were stealing fire hydrants, and selling them to scrap yards. There's a fire, and the fireman run over to attach the hose to the hydrant, and there's a base with a big hole in it, but there's no hydrant.

 

They show a YouTube video of how to steal a hydrant. Wrap a chain around it, hook it up to a truck and drive off. Breaks it off clean with the ground.

 

So my question is, when they break the hydrant off, why doesn't water go shooting up out of the pipe?

 

I recall an NCIS episode where Tony swerved to miss a bicycle jaywalker and ran into a fire hydrant and there was a huge fountain of water.

 

It seems like either the Chicago fire Department show or NCIS is wrong. Or maybe both of them.

 

What would happen if you broke a fire hydrant off?

 

 

I know this because I took my share of hydrants hit by cars over the years LMAO.

 

Fire hydrants are hooked into a different system than commercial water service because the volume/pressure requirements aren't compatible. To prevent freezing in cold climates, hydrants do not have water in them. Their supply is usually down at least five to ten feet and that's where the valve is, at that main. The nut at the top of the hydrant turns a rod that extends down to in.

 

This keeps the hydrants from freezing and when struck by vehicles, are designed to break away at the top flange, under the hydrant. No water gets lost because the valve underground is still intact.

 

In theory LOL.

 

Seen more than a few that the riser to the surface failed at the valve body creating quite a gusher. Literally. That much water will dig out quite the hole around where the hydrant was.

 

One fellow who had a hydrant in his front side yard, his house was less than ten feet from it. The vehicle took the hydrant and the riser out and the resulting hole from the water gushing for an hour until workers could locate the proper valve and shut it off ate enough of his yard that it caused that corner of his house foundation to fail.

 

The violator who fled the scene couldn't outrun the detectives who used the headlight assembly I recovered to nail down the make and model of vehicle and the approximate year. A canvas of local body shops and a nice lady across the street with a camera over her garage provided enough evidence to charge the driver.

His insurance paid off.....

[WOLFY]

there are wet and dry hydrants 

one turns into a geyser if it’s broken off the other doesn’t

 

in our city, the break-away section was there to prevent the violent removal of the hydrant from damaging the water main (it doesn’t affect whether you get a geyser or not)

Edited July 7 by WOLFY

[watab kid]

ive only lived in warm climates a couple times in my life so ive not a lot of experience with a wet hydrant , the valve on ours are at ;least eight feet deep here so when you are turning it on your twisting an inch and a half shaft - takes a big wrench and a younger man than i these days , they just replaced all of ours on this street over the last two years , 

nothing much new or different from what thy installed when they annexed us 30 years ago , and i dont think these utilities needed replacement but they wanted to replace our roadway as we demanded back then to have it similar to our township road [we didnt want the traffic or pedestrians a main road brings , we won , but this time they got more of what they wanted - wider paving and curb gutter and storm sewer , we did escape the sidewalks tho ,