Ardaman's Big Rig
- By: Colin Jewsbury
- , P.E.
- on
Ardaman has a new addition to their exploration fleet.
We are pleased to formally introduce our latest Cone Penetration Test (CPT) rig to the fleet line-up at Ardaman & Associates. Decades of experience in the CPT field has been systematically and thoughtfully applied to the design and custom manufacture of this latest build. The result is a truly one of a kind machine that is capable of handling Florida’s most challenging sites. We know her fondly as our HET-CPT rig (Heavy Exploration and Testing CPT rig).
At the heart of the new rig is an Oshkosh M1070 ultra heavy-duty truck. This former military vehicle is designed to transport M1 Abrams tanks into battle under the harshest of conditions. It can operate comfortably in extreme temperatures and has been described as “the ultimate off-road truck”. Although we have adapted this vehicle to serve as our CPT push platform, many other of these trucks find service all over the world, often in the mining, logging and heavy construction industries.
Although multiple options were available to us, some of the deciding factors in the purchase of the M1070 base unit included the presence of front and rear axle coordinated steering with 8-wheel drive, a central tire inflation system for each 17-inch wide super-single tire, and the ability of the truck to ford water without maintenance. Combined, these features allow us to operate on sites that other rigs and even all terrain type rigs can’t access or effectively traverse. This includes navigating tight spaces and obstacles as well as being able to drive over high vegetation including thick palmettos and small trees.
CPT testing uses hydraulic push to advance the cone tool. As such, the ability of a truck to push at a consistent 2 cm/sec and to penetrate hard layers is largely dependent upon the weight of the rig and how it is distributed over the push point. We constructed our rig with a heavy steel plate and hydraulic press optimally located to result in a full 30 tons of push force, more than most competitors in the Region. As such we have advanced cone soundings to well past 200 feet deep including through upper layers of very dense soils. Despite the weight, the HET-CPT operates well within its capabilities thanks to its gross vehicle weight rating of 43 tons and up to 115 tons when towing (after all, an M1A1 tank weighs 60 tons!).
Safety was the primary consideration in the design and construction of our HET-CPT. The press was set on a skew angle inside the cab creating a larger work area for the two-person crew. An oversized push port, large enough to install steel casing from inside the truck, as well as an automatic rod cleaning system and pedal operated clamps helps to keep hands clean and away from pinch points and operators away from danger zones. Cameras monitor both the front and back of the rig as well as underneath for easy and precise setup on test locations. The hydraulic press is fully enclosed inside a 14-gauge steel cab that is foam insulated which, in conjunction with dual integral air conditioning units, keep operators cool all day. Wall mounted TV screens allow observers to see results in real time without having to approach the press area.
Our HET-CPT is currently loaded with both conventional 1.44-inch HT digital cones as well as the larger 1.75-inch digital VTK cones specifically adapted for grout – through purposes. Grout is pumped through PVC tubing housed inside the steel rod string using a high pressure chemical grout pump. This approach is highly useful for push depths and locations that may encounter artesian type groundwater flows or even gas pressures.
Regardless, we hope this new rig may be of interest to you and please do not hesitate to reach out to us for whatever cone application you may have in mind.