Ground Resistance Testing at Marine Facilities

[richvalbuena]

Does anyone know an effective way to test the ground resistance of a grounding system on a wooden marine facility such as a wharf or pier? The nearest place to place electrodes in "earth" is about 1000ft away which makes using ground probes difficult. I also read that clamp on meters are susceptible to noise and may not be as accurate. The surrounding water seems to be the only place to put electrodes, however the water around the wharf is brackish and the amount of minerals/salt isn't always constant. Any help is appreciated.

 

[Jeffro]

Curious as to where the grounding electrode(s) are? Is this new construction and are there electrodes in place already? I use the clamp-type meters for testing grounds a lot and they seem very accurate-they better be for the price they are getting for those...

 

[brian john]

You are testing from the electrodes to ground?

As noted where are the electrodes?

These electrodes will need to be isolated to perform the testing

Lastly buy 2000' of #10 awg and afterwards head to the scrap yard.

 

[richvalbuena]

Ah, I didnt realize how confusing my first explanation was. I've never had to work with a grounding system over water and so far from land before so hopefully this clears it up...
The old ground system consisted of a worn out ground loop tied to 10ft steel railroad ties (electrodes) at various locations suspended in water via a chain. Testing the resistance of these electrodes gave inconsistent readings on the meter, which led to the removal of the railroad ties altogether and upgrading of the entire grounding system. It now has a newly installed 4/0 gnd loop, which is tied to new 'electrodes' (the steel pillars holding up the wharf deck at various locations) via bus bars bonded to the pillars. These steel pillars are buried 30ft into the sea bed and are essentially being used as giant electrodes.
My question is... is there any other way to test the ground resistance of those 'electrodes' without having to buy that 2000' of wire?