The new mid range Pit Viper 235 - Atlas Copco

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The new mid range Pit Viper 235
The star of
Minexpo 2008
The new ultra class haul trucks
in the Central Hall arguably may
have achieved the greatest visual
impact at MINExpo 2008, but surface
mine drillers attending the
record-breaking Las Vegas show
hailed their own new star in the
North Hall – the Atlas Copco
Drilling Solutions Pit Viper PV-235
at the Atlas Copco display. This
PV-230 class machine thus followed
in the tracks of the first Pit
Viper model, the PV-351, which
was launched at MINExpo 2000,
and the PV-270 series models introduced
at MINExpo 2004.
efficiency and productivity
The Pit Viper 235 has a weight on bit of
up to 65,000 pounds (29,500 kg) and is
designed for rotary or downhole (DTH)
drilling of 6-inch to 9 ⅞- inch (152 – 251
mm) diameter holes. Competitive performance
and excellent long-term reliability
have been key marketing points
for the Atlas Copco Drilling Solutions
range of drilling rigs for a long time.
The PV-235 is specified and fabricated
to maintain this reputation, with parti-
cular attention having been paid to the
reduction of horsepower demand and
non-drilling time. The cab and control
technology have been significantly
upgraded and the diesel engine options
are Tier II and Tier III units.
Atlas Copco Drilling Solutions has
again placed great emphasis on flexibility
in application, and the PV-235 is
available with any one of three towers
to drill 30-foot (9.1 m), 35-foot (10.7 m)
or 40-foot (12.2 m) clean 230-mm holes.
The new machine can be configured in
a surprising number of ways to offer
an optimal match to a mine’s particular
operating method and environment.
Like the PV-351 and the PV-270
models, the PV-235 will be available
with either a choice of diesel engines
or an electric motor. And it retains the
Pit Viper 235 is capable of dilling a single pass 40 ft clean hole.
hydraulic systems, including the rotary
head, that have consistently been preferred
by the Atlas Copco design and
engineering team for many years.
less mass, more options
Starting at ground level, the Pit Viper
235 has a newly designed platform.
It is built with two-speed hydraulic
excavator style Caterpillar 330 undercarriages
– the 330L for units with the
30-foot tower and with the 35-foot
tower, and 330EL when the 40-foot
tower is fitted. The dimensions for the
PV-235 version with tower up is 34 feet
2 inches long and 14 feet 6 inches wide
(10.4 x 4.4 m) A high speed lock-up
operates with the tower raised.
The plate steel frame is new to blasthole
drill construction and was designed
using finite element analysis. The
material thickness is one third that of
an equivalent welded plate construction
and has a better fatigue life. The frame
accommodates the 450- and 600-gallon
Blasthole Drilling in open pit Mining 61

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The enclosure option will reduce noise and provide cold weather protection; full-length doors offer easy
service access.
The hydraulic automatic cable tensioning cylinder is a time saver for maintenance .
For angle drilling the PV-235 uses a pivot at the base of the tower with adjustments from vertical to
30 degrees in 5-degree increments, while keeping the deck level.
fuel and water tanks, which are ISO
block, three-point isolation mounted.
An additional 400-gallon water deck
tank can be fitted if no dust collector
is used.
For safer, easier and quicker trouble
shooting and maintenance, the Grip Strut
open mesh deck provides excellent ac-
cess to the superstructure elements, including
ground level battery and starter
isolators, deck level access for the service
points on most systems, and quick
fills at waist level. An optional bolt-on
drum deck on the drill end adds extra
space for lube and other fluids storage
tanks, and cleans up the deck area to
allow 300° of access and improved
serviceability. Other optional fittings
include a central lubrication system,
fire suppression equipment, a jump
start receptacle and a spring-assisted
ladder.
For mounting on this platform, Atlas
Copco Drilling Solutions has decided
to offer customers a wider choice of
power system options than on previous
models. The structure is similar
to that designed for the Pit Viper 351,
with an independent sub-structure and
three-point mounting. But there is a
wider choice of Cummins or Caterpillar
engines, covering the range 540 – 800 hp
at 1,800 rpm with the Cummins QSX 15
to QSK 19 or Cat C15 to C27 engines,
all meeting Tier III regulations.
There is also a wider choice of air
compressors, as either single-stage
asymmetrical oil flooded Atlas Copco
or Ingersoll-Rand rotary screw units
are available for low pressure (1,200
– 1,900 CFM, 100 psi) rotary drilling,
and the two-stage equivalents for high
pressure (1,250 or 1,450 CFM, 350 psi)
downhole drilling. A new Electronic
Air Regulation System (EARS) allows
low load starting.
The hydraulic system has been
further refined with load sensing and
other features to reduce horsepower demand.
The heavy duty Funk gearbox is
driven by a drive shaft from the front
of the engine. There is one piston pump
for rotation; one load sensing piston
pump for the feed, set-up and auxiliary
functions; and one pressure-compensated
piston pump for the fan circuit.
The propel function uses the feed and
rotation pumps and there is an in-cab
62 Blasthole Drilling in open pit Mining

switch to select the diverter valves. The
valve rack is centrally located for easy
service access, at the same time simplifying
hose runs and control wiring. The
pressurized hydraulic fluid tank has a
capacity of over 100 gallons and the
filters are serviced at waist level.
To allow operation at ambient tem-
peratures up to 125° F (52° C) the cooling
system features oversized radiators.
Variable speed control helps to reduce
fuel consumption and noise and impro-
ves cold weather performance. The low
fan speed also lowers noise emissions.
Available as an option is a very smart
enclosure that further reduces noise, pro-
vides cold weather protection and has
full length doors for service access.
Towers
The open front structure of the three
towers available is similar to that used
on the other Pit Viper models – fabri-
cated from rectangular steel tubing by
certified welders and having four main
vertical members. The 40-foot (12.2 m),
35-foot (10.7 m) and 30-foot (9.1 m) hole
depths mentioned previously are the
distance from ground level to the bot-
tom of the hole, while the top of the bit
basket is 5 feet above ground level.
Using a starter rod and the updated
four-rod carousel, the 40-foot tower can
be used to multi-pass drill to a maxi-
mum depth of 200 feet (61 m). The car-
ousel features a spur indexing drive and
a parking brake.
The PV-235 is fitted with a standard
single-speed direct drive rotary head
that requires less maintenance than
other designs. Operating at 0 – 130 rpm
this unit provides a torque of 7,800 lbf-ft
(10.6 kNm) while the 200 rpm option
delivers 5,200 lbf-ft (7.0 kNm) of torque.
Alternatively there is an optional twospeed
head delivering either 4,250 lbf-ft
(5.7 kNm) at 200 rpm, or 8,800 lbf-ft
(11.9 knm) at 100 rpm. These rotary
heads are fitted with adjustable wear
guides. The spur gear head design used
on the present DM45 and DML rigs is
an option. The single cylinder cable feed
designed for the PV-235’s 40-foot tower
provides a hydraulic pulldown force of
60,000 pounds and a further improve-
ment in non-drilling speeds. The sheave
diameter: cable diameter (D/d) ratio
The RCS option provides various levels of automation.
is 22:1 and reverse bending of the cables,
which can create excess fatigue and
shorten cable life, is eliminated. The
pull-down rate is 140 ft./min. with the
40-foot tower and 193 ft./min. for the 35-
and 30-foot towers. Retract is 202 ft./
min. with the longest tower and 195 ft.
/min. for the other two. Auto-tensioning
of the cable, necessary to counter the
loss of tension caused by cable stretch,
is by means of a single cylinder with
exclusive balancing yoke.
For angle drilling the PV-235 uses a
pivot at the base of the rig tower, proven
on the earlier Pit Vipers, with adjustment
from vertical to 30° in 5-degree
increments. But the rear telescopic sup-
port legs provided on the larger rigs
are unnecessary. This single pivot de-
sign reduces non-drilling time signi-
ficantly, with tower raising and lowering
improved. The rig has a new two-
cylinder impact slide wrench for drill
string breakout that has replaced
the single-cylinder deck fork used
on previous models. The rear jacks are
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incorporated into the new tower rest,
as are the exhaust mounts, air cleaners
and lights. The arch-shaped rest adds
torsional stiffness to the frame and
riser arms secure the tower when it has
been lowered, reducing wear during
tramming.
even better cab
Together with the power system enclosure,
if fitted, the most distinctive
feature of the latest Pit Viper is the cab.
The cantilevered pod-type FOPS design
is a further advance on the progress
achieved with the PV-270 series machines
in terms of both capabilities
and appearance. Visibility is enhanced
not only by the shape of the cab and
large glass area, but also by tinted
windows, improved wiper/washers and
six Nordic integral lights (which also
consume less power than conventional
ones). The integrated air conditioning
system - with hydraulically powered
compressor, evaporator and condenser
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The FOPS designed cab offers excellent visibility and comfort.
– is mounted under the cab rather than
on the side. The Atlas Copco engineers
worked with the cab supplier to achieve
further noise reduction. For easier
“housekeeping” there are fitted floor
mats and a sweep-out door at the nondrill
end. Optional offers are a safety
camera system and a radio/CD player
for the cab.
The standard controls are electric
over hydraulic, with push buttons and
in-seat joysticks – one for each hand –
operating the key drilling and tramming
functions. Adding the proven Atlas
Copco RCS computerized network
rig control system, which is an option,
provides various levels of automation,
in common with the rigs manufactu-red
by the company’s surface and underground
teams in Sweden. For the PV-235
these options include remote tramming,
auto leveling and GPS navigation, all
A two speed excavator style undercarriage.
of which can help minimize non-drilling
time, and also measure-while drilling
logging technology. (See page 25 for RCS
explanation.) Prospects for the new Atlas
Copco Drilling Solutions model are good
if the Pit Viper 235 enjoys the same level
of success as its predecessors.
Dustin Penn
64 Blasthole Drilling in open pit Mining