Primary wire down causing ignition of underground gas main

[e92l44 0]

Date: 12/23/07

Time: 20:35 - 00:30

Location: South Riverside Avenue just south of Croton Point Avenue

Frequency: 46.26 / 460.3250

Units Operating: 2081, 2083, 2087, 20813, E120, E119, TL44, R18

Description Of Incident: Primary wire down causing ignition of underground gas main.

Writer: Remember585 (O/S)

At 20:35 E120 & R18 were dispatched for a wire down and burning at this location. A few minutes later, a commercial alarm was received south of this location. While units were arriving at both incidents, 60 Control dispatched units to a manhole fire at the Shoprite Shopping Center (same block). The first arriving command unit, Deputy Chief 20813, soon realized what appeared to be a gas-fed fire and requested a 2nd Engine (E119) to the scene. Apparatus remained on location monitoring the downed power line which ignited a fire from a 12" gas main. Flames were in excess of 25-30 feet at times, and were threatening a nearby excavating machine at E/T Equipment Center. Per Con Ed, E119 stretched a 1 3/4" line to protect the tractor until someone came and moved it. A Unified Command Post between Con Edison Gas, Con Edison Electric, Con Edison Emergency Management, Croton Fire & Croton Police was established and all units took up around 00:30. Engine 118 was relocated to Station 3 (Harmon) as a precaution and to handle any other incidents that came in.

The funny thing about this is, is that it's written right in th FDNY Books, I know that because I got it wrong on the last promotion test!

It says: When you have a primary/secondary power line down, the falling power line may cause a ruptured gas main.

When pulling up to the scene, no one is really thinking this may have happened, judging by the weight of the line, etc.? Most of us would think that a collapse or some large impact would be needed to cause a gas main to break, but obviously this has happened a few times.

Stay alert. Be Safe.

[FDNY 10-75 640]

How exactly does a downed primary cause a gas main rupture?

[grumpyff 1,159]

Electricity can travel through the ground (earth), and strike the gas main. Any small leak, or spark inside the gas main will cause ignition, and will rupture the pipe.

[FDNY 10-75 640]

Electricity can travel through the ground (earth), and strike the gas main. Any small leak, or spark inside the gas main will cause ignition, and will rupture the pipe.

Thanks! I have seen plenty of downed burning primaries, but have yet to experience a gas main rupture, leak or fire as a result.

Stay safe, Happy Holidays!

[e92l44 0]

How exactly does a downed primary cause a gas main rupture?

I would hope you could go down to D.C.A.S. and explain it to them, then I would've got the 70% and not the 69% that I got on test!!! Eventually, I'd be a Captain, D*mn It!!!!!!!!!!!! LOL!!!

Because of that question, I may be a Lieutenant for life...........not the worst thing...Ok guys......Merry Christmas to all......

I am not politically correct, it's 12/24, MERRY CHRISTMAS!!!

Let's keep up the good work, and keep looking out for ourselves.

Who else will?!?!?!?

[ny10570 745]

Live primary will almost drill its way into the ground. It'll cut its way down through pavement and earth right down to whatever lines are down there. Its really an interesting sight to see. Then after power is killed and you can fill the hole with water and watch it boil off. Its amazing how much energy is transfered into the surrounding earth.

[jack10562 414]

How exactly does a downed primary cause a gas main rupture?

What happens (with a steel main) is the electricity burns a hole in the pipe, very much like an arc-welder.

There doesn't necessarily have to be an existing gas leak.

In fact, the gas main involved here was 12" HDPE (plastic) @70 PSI, high-pressure main.

The heat in the ground melted the plastic.

There is current potential of tens of thousands of amps in any down primary.

The electricity flows down through the earth and forms a circuit, The white-hot heat of all the current flowing melts a hole in the pipe, and we get ignition.

All anyone can do is secure the scene and wait for the gas to be shut down.

[edit main material involved]

Edited December 26, 2007 by jack10562

[DOC22 1]

Live primary will almost drill its way into the ground. It'll cut its way down through pavement and earth right down to whatever lines are down there. Its really an interesting sight to see. Then after power is killed and you can fill the hole with water and watch it boil off. Its amazing how much energy is transfered into the surrounding earth.

We did a "wires down" call on Route 22 in Purdys, a few years back and it took over 1500 gallons to cool it down enough so DOT could patch the hole it burned in the driving lane. That thing was big enough to do severe damage to any car that hit it, so they had to fill it post haste.