With safety becoming a more important aspect of every construction project, the boring equipment industry is following suit.
This past January, Southwest Horizontal Drilling Services used their new ArmadrilloTM on a project in Forney, Texas, where they were subcontracted to 4D Construction. Southwest Horizontal Drilling, the contracting side of Chuck Webb's enterprise, is a partnership with Hector and Ismael Jalapa.
4D Construction is in the midst of a $1.1-million contract to upgrade infrastructure for the city of Forney: the Broad St. water line, which had required almost weekly repair; several sewer lift stations which will be removed, thanks to the tie-in with Rockwall/Heath/Forney waste project; replacing sewer lines that were installed in 1912 along Trinity and Main Streets; upgrading the 6-inch sewer behind McDonald's to 12 inches; and upgrading the 4-inch water line along Broad to 8 inches.
Southwest Horizontal Drilling was to install 10-inch casing for an 8-inch sewer line along the east side of Bois D'Arc Street and under several intersections to connect to the west side of the street. The soft clay made for easy drilling, and the crew was able to keep the 3-inch drill system online for a 0.4-percent grade on the 400-foot bore. But it is the Armadrillo's safety factor that attracts attention.
Many years in the drilling industry got Chuck Webb to thinking. And that led to the conception of a radical new technology for the HDD market.
Webb's new drilling system, that he and his partner, machinist Jackie Owens, market under the Armadrillco name, features patent-pending Arma-LocTM Technology, with its stainless steel lock pins and standard O-rings, that provide the extremely secure end connection.
"The pins will not vibrate loose like bolts sometimes do," according to Webb, "and because a puller or prying tool is used to remove the pins, there is no pipe wrench involved to kick back and strike the worker."
The side-loading sonde housing, the transmitter that allows the locating device to track the bore, also uses Arma-Loc Technology to secure the housing to the starter rod and the bits, and also to ensure that the sonde door will not open or become lost during drilling. Two sonde housings on different frequencies can be linked in-line for challenging tracking conditions, and can also be left in place during back reaming to keep track of the reamer. Uponcompletion of the bore, popping out six pins will remove the bit. Any make of reamer can be attached with an appropriate adapter.
Webb has designed two drilling systems: the Armadrillo is suitable for standard usage; whereas, the Sidewinder was designed for hard rock drilling.
The Armadrillo drilling system consists of a 3-inch side load sonde housing, offset bullet tooth bit, offset bit body for blades, starter rod, and a thread adapter for reamers.
The Sidewinder drills straight and cuts into a turn using standard locating equipment. It is rated for a maximum torque of 3,500 foot-pounds and needs no modification to be mounted on most web drill rigs, directional or pit launch — in sizes from a Vermeer 2440 or Ditch Witch 2020 up to a Ditch Witch 2720 Mach 1. The Sidewinder takes the place of a mud motor, but uses very little water. Only enough water or mud is used to lubricate the bit and flush the cuttings.
The shaft goes straight through the housing and turns with the bit, transferring all of the drill rig's torque to the drill bit. The transmitter, which is located only about 4 feet behind the drill bit, remains parallel to the shaft.
Their system allows a contractor to enter the HDD market relatively inexpensively, with a smaller drill rig, yet with the capability to perform the tough jobs.
The American Airlines maintenance facility at Alliance Airport north of Fort Worth has been experiencing soil heaving — about 3 inches at its worst — that would greatly damage the building where jets are repaired if steps had not been taken soon.
Engineers from American Airlines determined the problem stems from groundwater that continues to seep into the native "black gumbo" soil from the location of a lake that was filled near their property.
Southwest Horizontal Drilling and H2M Utility Construction, LP were contracted as consultants to solve the problem. Their answer was to install a 6-inch PVC sewer line with weld casing to drain the water out from underneath the building.
Because the maintenance facility uses a lot of electronic equipment that could cause interference, and the concrete slab is 10 inches thick, Southwest Horizontal Drilling will be taking extra precautions with their locating system. They have hooked two sonde housings in-line behind an Armadrillo, one tracked with radio detection and the other with a DigiTrak.
"That way we have a better chance of knowing where our head is," Webb said. "In case one of them has trouble, we'll know where the other one is." Southwest Horizontal Boring will drill to about 20 feet under the building.
"We're going to run a steel casing with holes cut into it so water can get inside," explained Webb. "Then we'll run a PVC pipe with slots inside that, and hook it all up to a water pump to drain the water out from under the building. The engineers believe that will stop the heaving, although it may not lower the ground from what has already occurred." Southwest Horizontal Boring experienced good results from a similar treatment in Corsicana.