Air Hammer Posts

BREAKING NEWS – RockEye Hammer System Receives Major Upgrade

Armadrillco for RockEye

Armadrillco High-Flow/Side-Load Housing Adapted to the RockEye

The spring 2017 acquisition of Armadrillco® solidified StraightLine HDD’s position as a leader in hard condition tooling. The announcement today of the adaption of the patented Armadrillco transmitter housing to the RockEye® Hammer System is a significant step in diffusing Armadrillco technology throughout StraightLine HDD tooling platforms.

Adapting Armadrillco side-load housing technology gives users easy access to electronics, larger capacity fluid/air passages and improved durability. The housing’s patented Arma-Loc® system is a field-proven design that gives users quick access to electronics by virtue of removing a single pin. Free from threads, the Arma-Loc system virtually eliminates problems associated with damaged or over-torqued bolts, as well as vibration-induced lid failure.  

The RockEye Hammer System is a proven tool for hard rock conditions.

The industry’s most secure lid retention system is also the most protected. Working in tandem with the Arma-Loc lid security system, a patented urethane and O-ring system is designed to seal and protect the sonde cavity from fluid/debris infiltration.

The system also forms a cushioned platform that shields valuable electronics from punishing vibration and heat produced by a hammer working in harsh rock environments.

Large internal passages, up to 1-inch in diameter, represent a significant improvement in air/fluid flow. The larger passages are capable of delivering air volume up to 1,200 CFM and fluid volume of 300+ GPM.

Job Site Stories: RockEye Hammer Rocks Two Ohio Pipeline Segments

Location:  New Philadelphia and Ashland, Ohio

Equipment: StraightLine HDD® RockEye 5.0 Hammer System | Vermeer 80x100 | 1150x350 compressor


A major petroleum-transport infrastructure company was awarded contract to install a 215-mile connector pipeline. The 12-inch heavy-wall steel pipe was to link a processing facility in northeast Ohio to an existing pipeline in north central Ohio.  

Subsurface condition surveys revealed bedrock comprised of Pennsylvanian and Permian-aged sedimentary rock, primarily shale, sandstone and limestone. A part of the Allegheny Formation, overlying the bedrock was a layer of glacial deposits consisting of clay, sand, gravel and boulders.

Beyond the challenging geology, the project kicked off under a public relations cloud created by an accidental discharge of nearly two million gallons of drilling fluid into a wetlands area. Although the spill occurred on an unrelated pipeline project by another contractor, continued media coverage created an elevated sense of urgency to control drilling fluids.  

Ohio Air Hammer Job Site

The first hammer shot on the 215-mile connector pipeline project occurred on a 300-shot through a rock formation that thwarted several attempts using conventional tooling.

Vermeer 80x100 outfitted with RockEye hammer.

A Vermeer 80x100, outfitted with a RockEye 5.0 Hammer System, moves into place to attack the 300-foot limestone bore.

Limestone rock

Part of the Allegheny Formation, to get into the limestone bedrock layer, the crew had to push through a layer of glacial deposits consisting of clay, sand, gravel and boulders.

The RockEye Hammer System, played a key role in completing two sections of the pipeline project; near the towns of New Philadelphia and Ashland. Conventional methods and tooling were initially specified on both bores. But, as is often the case with HDD, even meticulous planning, executed by seasoned professionals require “on the fly” adjustments.

Bore #1: New Philadelphia, Ohio

With several successful bores under their belt, the veteran crew’s confidence was high as they arrived on the New Philadelphia site. That would change abruptly, on the short 300 foot shot. Steering was the core issue.

Finishing the pilot

After punching the pilot shot, the crew prepares the first of two back-reams.

Entry angle was set at an aggressive -20 degrees, in order to achieve total depth of 12 feet, which included a minimum 4 to 5 foot clearance of three installed pipes. A tight easement, combined with the limited bend radius of the 12-inch heavy steel pipe, meant there was little margin for error in steering.  Problems emerged as the conventional rock bit moved from the clay/loam glacial till into the limestone.

Unable to effectively engage the rock, the tooling simply bounced off the rock.  After spending several frustrating days unable to stay on-profile, a crew member recalled watching a RockEye Hammer video on YouTube. Another crew member recounted witnessing a RockEye in action with a previous employer.

A call was placed to StraightLine HDD. Within days, StraightLine Field Engineer, Ron Becker arrived on the job site with a 5-inch RockEye in tow. Following setup and briefing, the hammer entered the ground mid-morning. Arriving at the point where previous conventional tooling deflected, the RockEye fully engaged the limestone.

After spending two rods with Becker teaching technique, the operator completed the day, logging impressive production rates of 15 to 20 minutes/per 20 foot rod. Less than two days later, the hammer hit the exit pit. Production rates, while notable, the control exhibited by the RockEye left a lasting impression.  

The drill foremen summed it up best: “It (the RockEye) makes an impression.  Especially after you’ve spent a good amount of time without much to show; then this hammer comes in and immediately bites into the same rock we were bouncing off of the day before.  And then, with total control, finishes with ease.”

With the pilot completed, the crew set up for a two-step hole enlargement using 12- and 18-inch hole openers. Aware of the need to control drilling fluid, StraightLine Field Engineer Ron Becker took the opportunity to demonstrate one of the lesser known advantages of the hammer: using air rather than fluids on the back ream.

Running the compressor with a fluid flow rate of seven gallons/minute, both enlargement passes were completed in less than one day. “What the demo clearly showed,” observed the drill foreman, “was that air is a legitimate technique to minimize frack-out risk), while effectively transporting cuttings from the hole.”

Bore# 2: Ashland, Ohio

Two weeks later and 50 miles to the northeast of New Philadelphia, another crew set up for a 450-foot shot near Ashland, Ohio.

Although less congested with installed utilities, the bore had its own set of challenges.

Second RockEye Bore

The second RockEye bore was the 450-shot through limestone.

The bore profile called for a 6-foot minimum clearance under a wetland area—and a total depth of 9 feet. With the entry positioned a short 40-feet from the water’s edge and considering the limited bend radius pipe, steering would again be a challenge.

The crew opted to lower the entry point by excavating a 7-foot pit. The crew calculated that lowering the launch point, when combined with rising topography on the exit side would make it much easier to navigate the alternating limestone layers and sporadic shale seams—and still stay within the bend radius of the pipe.

With a number of days remaining before taking delivery of their own RockEye Hammer (purchased following the successful New Philadelphia bore), the crew geared up with a three tooth rock bit. Ten hours of hard drilling netted 180 feet. However, lack of control placed the bore off-profile—negating most of the production.  The crew pulled back and re-fitted with second rock tool. The results were the same. After pulling out the crew moved to another pipeline section, while arrangements were made to bring in Becker and the RockEye demo hammer.  

Setting up a new pipe basket.

Positioning a new pipe rack on their Vermeer 80x100.

Three days later, Becker arrived. Moving 4 feet from the previous hole, in a half a day of drilling, the hammer reached the point where the previous traditional rock bore ended—this time, the bore was on-profile. Just as the crew began to entertain the possibility of finishing the 450-foot pilot in less than two days, the bore “Gods” intervened. 

The hammer intersected a large void (likely made by the previous bore attempt). The rock caved-in, instantly pushing the hammer from a positive 4 to negative 2 and causing the hammer to bind. The crew, realizing navigating from the cave-in would violate the pipe’s bend radius, made the call to pull out. Moving the entry point once again, the RockEye engaged the limestone, achieving a consistent rate of production of 15 feet, every 20 minutes. Two days later, and without further incident, the RockEye hit a perfect bull’s eye on exit. Similar to previous segments, the crew executed a two pass hole enlargement in a single day—again demonstrating the effectiveness of air on the back ream.

As the crew prepared to move to the next job site, the drill foreman lamented: “The RockEye performed exactly as advertised—in fact, short of a mud motor—which was not an option on this bore—I  don’t think we would have gotten this thing completed without the RockEye hammer.”

Job Site Stories: RockEye Hammer Notches Win in Georgia Limestone

Comtran Group uses RockEye to drill tough limestone

Location:                             Atlanta, Georgia

Equipment:                       RockEye 3.0 Hammer | Vermeer 20x22 | 400x200 compressor


Buford, Georgia-based Comtran Group, Inc., received a contract to drill a 350-foot rock bore in a North Atlanta residential area. Passing through terrain of rolling hills, the job was to install 2-inch communications conduit.

Part of the Piedmont geologic region, the area contained ancient igneous and metamorphic rock, hardened by high temperatures and pressure. The limestone on the job site was estimated to have a hardness of 30,000 PSI.

Urban set up

The Comtran Group crew sets up to drill a 350-foot rock bore in a North Atlanta residential area.

Limestone rock

Conventional tooling was no match for the limestone rock, estimated to have a hardness of 30,000 PSI.

Locate markings show the RockEye's ability to make steering adjustments - a point that was not lost on the crew.

At 200 feet from the entry point, the bore path intersected an underground water storage vault. The bore plan required a depth of greater than 20 feet to clear the obstacle.  The exit point—located ten feet below entry—worked in the crew’s favor by flattening the steering required to clear the underground structure and made navigating to the exit pit much easier.

The job site’s residential location brought the typical restrictions on noise, fluid management and site footprint.

The last 100 feet foam was added.

For the last 100 feet of the bore, a small quantity of Cetco Versa foam was added to the air/water mix.


Initially, the crew opted for conventional tooling and methods. Using a popular conventional rock head, the crew made several attempts—including attacking the bore from both directions. Each attempt yielded similar results: average but not “usable” production, due to the inability to control the head.

After several days drilling with little to show, the Comtran crew considered their options. An operator with previous hammer experience suggested using a StraightLine RockEye hammer. A demo was quickly arranged.

Arriving on-site with a 3.0 RockEye, the hammer hit the ground around 9 a.m. The first day’s production was slow, but steady, averaging 30-40 minutes per rod. As the first day concluded, the RockEye was 175 feet out— a little more than previous conventional attempt – but with one big difference: the hammer stayed on-target, making fine steering corrections on demand.  Additionally, using an air/water mix to remove cuttings virtually eliminated site clean-up; a crew morale booster as the crew closed up the job site for the night. 

Day two began much the same as day one: steady, on-target production. However, as the bore hit the 250 foot mark, cuttings removal stalled. A common problem when using small compressors on restrictive urban job sites (to meet noise/space restrictions), the crew anticipated the issue and added a small quantity of foam to the air/water mix. With cuttings flow restored, the RockEye hit the exit pit by late afternoon, leaving enough time to pullback product by the close of the day.

Money shot

Following several failed attempts to complete the 350-foot bore with conventional tooling, the RockEye Hammer punched through the limestone in less than two days.

Wrapping up the bore, the Comtran Group operator marveled: “Drilling and pulling back in two days—and having total control the whole time: it’s amazing.”

Advantage RockEye, Part III: Production

In the decade since launching the RockEye Hammer System, we've spent quite a bit of time helping contractors put holes in some of the nastiest rock out there. During this time, the first thing most of these contractors mentioned was the surprising rate by which the RockEye pounded through rock.  

Here's one such story from North Carolina.  And another one from Kansas.


Job Site Stories: CMP Technologies, Inc.

Location: Charlotte, North Carolina

Equipment: RockEye 4.0 Hammer System, Vermeer 23x30 with Atlas Copco 1000x350 compressor

The Challenge:

North Carolina-based, the CMP Technologies was tasked with a 400-foot bore to install 8-inch poly pipe. The site, located in the Charlotte, North Carolina, Center City neighborhood, required a 20-foot depth, an aggressive 12 degree left turn to follow the easement and a fairly rapid 12-15 foot ascent to reach the road cut.

Part of the state’s Charlotte Belt formation, lurking 10 feet below a mix of course gravel and loam was very old igneous—mostly limestone—rock.

Conventional Methods Attempted First

Conventional rock methods & tools were initially specified. Hitting the ground hard on the first day, the CMP crew easily punched through the first 80 feet of soft soil. Hopes of a short work day ran high.

CMP Technology Charlotte bore path traveled through a varied mix of soils.

The hard limestone conditions in the Charlotte, North Carolina Center City neighborhood stymied initial drilling attempts using conventional rock tools.

The 400-foot bore was located in the shadows of Bank of America Stadium, home of the NFL’s Carolina Panthers football team.

The enthusiasm ended quickly as the bore transitioned from soft soil into limestone. The three-tooth rock bit simply deflected off the rock. Changing the attack angle partially solved the deflection issue, but exposed a bigger problem: the rock bit simply would not cut the rock.

With production stalling, a crew member suggested contacting StraightLine HDD®. Having witnessed a RockEye® Hammer System in action with a previous employer, the crew member recalled the RockEye’s ability to steer and produce in similar conditions. A demo was scheduled.    


StraightLine field engineer, Ron Becker, arrived at the job site armed with a 4.0 RockEye. Following a quick bore review, set-up and operational briefing, the hammer hit the ground around mid-morning.  

Immediately, Becker realized the soft soil provided inadequate support to the bent sub (giving way rather than allowing the bent sub to push off). “We run into this frequently,” says Becker. “We adjusted technique by increasing forward pressure, which allowed us to push and steer the assembly through soft stuff.”

CMP Technologies working in Charlotte, North Carolina

Operating the RockEye, production rates clocked an impressive 15 feet/10-foot rod. Equally impressive was the flawless execution of a 12 degree turn.

Pushing through the soil layer, Becker recounted the moment the RockEye handled the transition between soft and hard conditions. “You know exactly when the hammer moves into rock—because you can hear it.”

“Once we had established a foothold in the rock—at the correct trajectory—then it was a matter of establishing a rhythm using the hammer’s carving technique” noted Becker.

As the sun set on the first day, the bore neared the halfway point. Production rates averaged 15 minutes/10-foot rod.  The following morning, production continued to impress. Even on the 12 degree turn, production consistently clocked 30 minutes/10-foot rod production rates. Just ten hours after the RockEye arrived on-site, the CMP Technologies crew completed the 400-foot pilot shot.

“A lot of times, we come in after the contractor has spent days—even weeks—trying to get product in,” says Becker. “So when we get 40 plus feet production per hour, and knock a bore out in a couple of days, there’s usually a mixture of shock and amazement on the job site. That’s what we had here.”