stump grinding general question

[dig-dug-dan]

Travis perkins hire some kit that you plug into the householders elec socket, and it picks up all services, even plastic pipes. Was about 700 to buy I believe.

there is also a website, beforeyoudig I think its called, that should assist in finding pipes and services.

gas and water are ok to repair, but fibre optic is a different ball game!

[Hodge]

They wanted £900 quid to repair the gas line.

[dig-dug-dan]

That sounds about right. Mate cut through one with his hedgecutter the other week, but got out of paying as the installer had not put warning tape over it, and then just stuffed it in the hedge

[fergusonforestry]

I don't know many who don't.

 

at the council we didn't it got lost and that was that!!

[openspaceman]

Well I don't use one, but I'm beginning to think I should.

How much are they? And what sort of training do you need?

 

The ones we use are about £450. The training is about 1/2 day and needs refreshing every 2 years where I work.

 

The theory is simple, the device picks up electromagnetic radiation that escapes from a conductor carrying a current, it listens for the "noise" given off. The Cscope ones I use have 3 different listening modes, the first is for mains "hum" at 50hz and possibly its harmonics, the second is radio frequencies which the cable can pick up from equipment attached to the electricity supply and from the general background as it acts as an aerial. The third is special, it is tuned to the frequency of a signal generator that can be attached to one end of a cable or can be induced into a cable which is at a known point. This latter is especially useful as the aerial in the detector is at two different levels and it can calculate from the difference in time each level receives the signal how deep the cable is. They have to be recalibrated regularly to be certified for use and battery level needs checking before use.

 

From the above you will see if there is no activity on the cable, even if it is live, it will not have any "noise" and will not be detected. similarly no conductor then no signal so an all plastic or fibre optic pipe cannot be detected unless it has a conductor incorporated or laid with it.

 

Main lesson is to use all frequency modes to mark what cables can be found and avoid them but then not assume that if no signal is found there is no cable or service there.

[Paul Cleaver]

The ones we use are about £450. The training is about 1/2 day and needs refreshing every 2 years where I work.

 

The theory is simple, the device picks up electromagnetic radiation that escapes from a conductor carrying a current, it listens for the "noise" given off. The Cscope ones I use have 3 different listening modes, the first is for mains "hum" at 50hz and possibly its harmonics, the second is radio frequencies which the cable can pick up from equipment attached to the electricity supply and from the general background as it acts as an aerial. The third is special, it is tuned to the frequency of a signal generator that can be attached to one end of a cable or can be induced into a cable which is at a known point. This latter is especially useful as the aerial in the detector is at two different levels and it can calculate from the difference in time each level receives the signal how deep the cable is. They have to be recalibrated regularly to be certified for use and battery level needs checking before use.

 

From the above you will see if there is no activity on the cable, even if it is live, it will not have any "noise" and will not be detected. similarly no conductor then no signal so an all plastic or fibre optic pipe cannot be detected unless it has a conductor incorporated or laid with it.

 

Main lesson is to use all frequency modes to mark what cables can be found and avoid them but then not assume that if no signal is found there is no cable or service there.

 

 

some useful info

[bumble B]

Always good to check what you're covered for as well. Going through services will be costly on your pocket and you will be surprised how many people will find out your discrepancy.

[Pommie]

We use a cat & genny when stump grinding

[Acg128]

We use a cat & genny when stump grinding

 

Persian cats ok?

[bob]

We have a little pussy we take

Had some training on it as well

Hit a gas main sadly we had not taken it that day

Had to pay but wouldn't of had to if we had scanned I was told or had stats on site