Full marks for Pit Viper 311

January 15, 2015

Atlas Copco’s new Pit Viper 311 has successfully completed rigorous field testing at a copper mine in the USA, confirming the value of the rotary drill rig key design features.

The latest member of Atlas Copco’s blasthole PV-310 rotary drill rig range – the Pit Viper 311 – has recently completed a six month field test at a copper mine in the southwestern region of the United States. The result: full marks on all counts.

The prototype PV-311 went into service at the mine with the focus on cooperation between mine personnel and Atlas Copco engineers to test modifications that would help increase productivity and efficiency.

“The PV-311 had no trouble managing rough conditions while consistently hitting its targeted depth and maximizing the quality of the hole drilled”

Maureen Bohac, Product Manager, Large Blasthole Drills, at Atlas Copco

The PV-311 drilled 255 mm (10 5/8 in) and 317 mm (12¼ in) diameter holes – the largest hole this rig can drill – on benches 15 m high. The 255 mm holes were drilled to a depth of 17 m with 2 m of subdrill, while the 317 mm holes were drilled to a depth of 20 m with 3 m of subdrill.

Five different drill patterns were used depending on the location of the test in the pit. The rig typically completed 35 to 40 holes amounting to 365 meters drilled in a 12 hour shift. The average availability was 90–95%. The rock encountered in the mine is typical of most copper applications, not homogeneous and with a compressive strength around 250–300 Mpa.

Atlas Copco Secoroc Tricone/DTH bits were used with each bit lasting 2.5–3 days. The prototype rig was subsequently purchased by the mine.

“One of the contributing factors was that the PV-311 is designed so that the bits are changed above the rig’s deck, even while single-pass drilling a 20 meter deep hole.”

Maureen Bohac

This enabled the operators to focus on making and breaking the pipe connections each time.

The PV-311 during field testing at a U.S. copper mine. Several design features in combination enabled the rig to drill 20 m holes with excellent hole quality and more.

The PV-311 during field testing at a U.S. copper mine. Several design features in combination enabled the rig to drill 20 m holes with excellent hole quality and more.

“In addition, this prototype included our optional hydraulic clutch, which is designed to reduce fuel consumption during non-drilling operations and this had a big impact. Another factor that influenced fuel efficiency was the autodrill functionality of the rig’s RCS rig control system.”

Maureen Bohac

Fuel efficiency was approximately 20 per cent better than other rigs on the site. On top of this, the PV-311’s quiet and comfortable cab proved to be especially appreciated by the operators

“Fuel efficiency was approximately 20 per cent better than other rigs on the site. On top of this, the PV-311’s quiet and comfortable cab proved to be especially appreciated by the operators”

Maureen Bohac

The PV-311 is now production drilling at mines on three continents in applications including copper, coal and iron.