Well, I thought I would share last nights activities as it was a first for me. We are tapping into two 12KV manholes to provide power for two new substations at an international airport. The manholes are in the street in the middle of the roadway where people are dropped off and picked up. (You know," the white zone is for loading and unloading only") Luckily this airport stops flight operations at 10:00PM so we have a 7 hour window to get machinery in there, dig. This was the second night and everything was going great...and then... THE BACKHOE HIT A GAS LINE! That's when it all starts. Panic mode. The fire and sheriff departments rolled and the Sheriff closed the road way into the terminal. This is all at about 3:30AM and they start loading plans at 6:00. To make a long story short the hazard was cleared without two much delay and people were let in to get the airport up and running, but the gas line is probably still not repaired as I write this. So the restaurants will be serving pastries and orange juice this morning I guess.

PS: Yes we called Dig alert prior to digging and did our due diligence in trying to obtain accurate as built info from the airport so we should be out of hot water. It still makes for an interesting night!

(Flash back to what was going through my mind)
Flight XXX Delayed
Flight XXX Delayed
Flight XXX Delayed. You get the picture!

Nick,

Boy, it sounds like you really know how to throw a Party!


Bill

Nick,
you've probably made Homeland Security's list

Nick,

TOO many times I have seen where the utility company's go aout and mark, water, electric, gas, telco, etc. yet, they are marked in the wrong spot. There was (Once upon a time) when ATT had the under water over sea lines around here and if you hit that, it would bankrupt your company. A friend of mine had the telco co. out on a job with his back hoe. The telco man said, "Take another shovel full." OK, that was good, then another, and another, then OOPS! There was a hundred underground telco lines in the bucket. Well that telco man lost his job right there on the spot. So much for laying out the job.

How would you like to be the track hoe operator that, while working on the local highway project, pulls up the major North-South fiberoptic cable? Happened here last year. Talk about a sinking feeling.

On a smaller scale, I can never stick the backhoe bucket in the ground here at the railroad without coming up with something I didn't want.
TW
TW

I dug up a 1500 pair tree root once (at least that's what the phone company spotter said it was

I was told the following story when I visited the local (3000 MW) nuclear plant in mid Feb.

Previous week the plant had been running at maximum power, since it was way below freezing and many houses in Sweden are electric heated. Someone had scheduled repair of a non-critical fault to the outgoing 400 kV lines during peak load hours. (Great idea!) The contractor sparkies went out to the disconnects outside the plant and started to shut down the lines - WITHOUT INFORMING THE CONTROL ROOM!!!

Next thing, the reactors run wild since they have nowhere to put the power. Automatic emergency shutdown. The first reactor shut down before the guys in the control room had figured out what was going on and managed to stop the sparkies. Luckily, there was enough headroom on the national grid to compensate the loss of one reactor. The loss of two reactors would have meant a nation wide blackout...

(I hope the subcontractor had a good insurance!)

Nick,
When I first started reading your post, I could have sworn that you were talking about Intercontential in Houston. Believe me, I know about the 10PM to 5AM window that everything has to be done.
A couple of weeks ago, we had to extend a branch circuit for a vent motor. This vent motor was mounted inside of a 36" concrete reinforced pipe. The shaft had to be extended across a street. So, the GC dug up half the street at a time. At about 3:15AM we were half done. Things started "hopping" around there because the vent was for an underground tunnel that had to be turned back on before the "big morning rush". To make a long story short, they were 10 minutes late getting the road opened for traffic. The problem was, they (the GC) didn't remove the hardware for the vent motor housing. I hooked up the disconnect for the motor, and was about to throw the switch when I noticed the vent fan housing was hanging from from the existing seal tite. If I would have turned on that motor, it would have probably shaved the wires, and dropped to the bottom of the shaft, approximately 8 feet. After some quick thinking, we worked it out, and had the motor on by 8AM.

So much for deadlines,
Doc

Great stories!
The preverbal **** hit the fan the following day and the finger pointing and letter writing has begun. They wouldn't allow us to do any more digging last night with machines. They were bringing in a company to x-ray the rest of the trench line to see if there is any more UFO's( unidentified buried objects.) The results won't be in until Monday so we got shut down for tonight. (lost a night of double time ) Like I thought McDonalds suffered the most and that's where the revenue lose is most rearing it's ugly head.
The nail biting isn't over for this one. In a couple of weeks we have to relocate some 3 and 4000A busduct in 4 hour windows. Let the fun begin!

So, Nick, are you a lineman for a PoCo?
There is manhole out at IAH that is in the process of being moved. I don't know how they are going to do it. Funny how things turn out. That manhole is right dead center of a future foundation for a column which supports the bridge deck of the new APM guideway between terminal "C" and "D". APM stands for Automated People Mover. It's jsut a "high dollar" train with no driver.

Just being nosey,
Doc

Nope, I am not a Lineman. I'm an Inside wireman. The whole 12KV system is owned by the airport not the PoCo. The meter is in a 66KV substation down the road a bit.

It's always a lot of fun when we inside guys start messing with Medium Voltage. I wish I had more experience with it.

Keep your hot gloves handy,
Doc

A couple of months ago a team of workmen repairing a road surface nearby hit a tel. cable and took out all the phones in my settlement.

Some years ago I recall hearing about a team of outside contractors working at Goonhilly (big telecoms satellite station in England) who went into an underground 11kV feeder, though fortunately it was isolated at the time. When hauled before the boss, apparently the "head digger" said he saw the bright yellow and black marker tape "Danger: Electric cables below") but didn't think it mattered!

For underground service conductors only [not for feeders or branch circuits] up to 600 volts when not encased in concrete and buried 18 inches or more below grade, are required to have their location identified by a "warning ribbon" that is placed in the trench at least 12 inches above the underground installation. 300.5(D)(3)

No ribbon is required for feeders and branch circuits because they contain short-circuit and overload protection.

Table 300.50 for over 600 volts ......

Exception No. 3: The minimum cover requirements do not apply to conduits or other raceways that are located under a building or exterior concrete slab not less than 4 inches in thickness that extends not less than 6 inches beyond the underground installation.

A warning ribbon "or other effective means suitable for the conditions" must be placed above the underground installation.



[This message has been edited by Joe Tedesco (edited 10-20-2002).]