The Macro-Core® 1.25 in. Center Rod System was designed for the absolute worst of the worst direct push probing conditions. “These are conditions that we normally do not recommend probing in,” according to Mike Carlin, Project Engineer, “so we developed the toughest soil sampling system in the direct push industry ... it’s a brute!”

There are no stop-pins, no piston rods, no couplers – just probe rods – for this Macro-Core® sampler. “We had two initial sites to test this product,” Mike said. “We went to a site where we had previously encountered buried slabs of concrete which made most soil sampling methods impractical.” Augering was out of the question, and other center rod sampling systems were not effective. The second site was in Alaska.

The Macro-Core® Center Rod System consists of a standard Macro-Core® sample tube, cutting shoe, and piston point. A 1.25 in. “center rod” probe rod serves as the inner rod system and holds the piston point in place. The sampler is driven to depth with 2.25 in. probe rods. Once the desired sampling interval is reached, the 1.25 in. inner rod system is removed. At this point, the Geoprobe® hydraulic winch is especially useful. “By using the winch to pull out the inner rod string, sampling can be done much faster than with other center rod systems,” Mike explained, “and it can also save the machine operator time and energy.” With the inner rod string removed, the sampler is driven through the sampling interval to collect the soil sample. The piston point is easily displaced as the sample is collected. This easy displacement helps eliminate sample compression so sample recovery is not compromised. Once the sample is collected, the tool string is removed and the sample retrieved.

Geotek Alaska also used the Macro-Core® Center Rod system for a geotechnical soil investigation at the Bethel Airport in Behtel, AK. Soils at the airport consist of sandy silts, ice lenses, and permafrost. The work consisted of gathering soil information to a depth of 30 feet for the AK Department of Transportation to facilitate the construction of runway work at the airport. According to Scott Voijta,owner of Geotek Alaska, “the new Macro-Core® system was crucial in performing this project. It has the durability to displace the frozen soils which allowed the advancement of the MC system through the slough generated during coring.” Scott is a big fan of the new MC system. “The success of testing this new MC system,” Scott added, “has given us an increase in confidence, in production, and in profit.”

Macro-Core® is a Registered Trademark of Kejr, Inc.
			Geotek Alaska tests the Macro-Core® Center Rod System at Bethel Airport. Testing the new system through ice lenses and permafrost was deemed a success for the field crew. The durability of the system allowed Geotek to probe in much toughter soils. Fewer parts speed up decontamination and re-assembly of the sampler which increases the company’s footage/production rate.
			“I can use my machine for just about anything the environment throws at me!” Scott Vojta, Geotek Alaska