Underground Construction - September 2018 - F

The unique dual pipe drilling system of the
All Terrain models is shown here.

New Advancements for the

The Ditch Witch® AT40 brings new innovations and advancements to the all-terrain
(AT) mechanical dual-pipe drilling system
the company introduced more than 20 years
ago. This technology is credited with changing underground utility construction by
making it possible for mid-size HDD equipment to efficiently and economically make
utility installations in hard-rock formations.
The patented AT system uses an inner rod
to drive a rock bit, and the outer pipe to steer
the downhole tool while drilling the pilot
holes and provides rotary torque for the hole
opener during backreaming.
Since its introduction, the AT system has had numerous improvements
and refinements, and the advances in the
40,000-pound pullback AT40 represent its
latest evolution.
"At the core of the enhanced AT40 is a
dual-pipe system that has an inner drive
shaft that reaches back to the drill, so the
operator can physically control exactly how
much horsepower is sent downhole," said
Cory D. Maker, HDD product manager,
drill pipe and fluid management. "With
this system, 95 percent or more of available
power is transferred downhole. Compare

AT40

that to the 50 percent of power a mud motor
can send to the drill bit."
Because the AT drilling system is mechanical, the equipment requires about the
same amount of drilling fluid as a standard
drill.
"In addition, advanced AT systems provide 33 percent more torque than competitive units."

Drill pipe
New drill pipe has been developed for
the AT40. The flush pipe features nextgeneration inner-rod design with a patented
12-point hex for easy and reliable makeup
of the inner rod, and optimized fluid and air
flow. Able to store onboard 350 feet in 15foot pipe lengths, AT 40 helps reduce cycle
times and increase production.
The advanced AT system also features an
enhanced RockMaster® housing adaptable to two different sizes of drill bit: 2.875
and 3.5 regular API standard connection.

Unmatched Service and Support
Ditch Witch products are sold and serviced by the worldwide
Ditch Witch network of more than 175 dealerships, which
inventory genuine Ditch Witch parts and offer expert product
maintenance and repairs. Ditch Witch is a Charles Machine
Works company based in Perry, Okla.

A patent-pending, steering-offset design
eliminates the need for a universal CV joint
to reduce fatigue in the shaft and allows a
two-degree bend for steering.
The RockMaster housing has an industryexclusive, double-layer seal with high-capacity bearings for increased downhole life and
improved reliability. Service time intervals
are doubled compared to previous models.
The platform for the AT40 is the proven
and popular Ditch Witch JT40 drill unit.
The JT40 is available with a 160-horsepower
Tier 4 diesel engine or 148-horsepower Tier
3 diesel engine for use in areas with less
stringent emission requirements. Rackand-pinion carriage drive and a new, proven
hydraulic platform provide power for drilling
and pullback.
In addition to 40,000 pounds of pullback
and push, the JT40 develops a maximum
spindle torque of 5,500 foot/pounds, and
spindle speeds up to 225 rpm. Maximum
carriage thrust and pullback travel speed is
180 fpm with industry-leading cycle time.
There are also standard and heavy-duty
stake-down options.
A new pipe rack design allows access from
either end. A mesh side panel allows viewing
of the pipe supply from the operator's seat.
Pipe boxes hold up to 600 feet of drill pipe.
The patent-pending open breakout system
is positioned closer to the operator than on
previous models.
All functions can be operated with a
handheld, wireless control device (the remote
ground drive control is not operational
when the operator is seated in the operator's
station).
Maintenance points are easily accessed by
opening or removing steel side panels and
lifting a fiberglass hood that is easily raised.
The AT system can be swapped out for
a standard, single-pipe drilling system in
standard drilling operations.
Other models in the AT line include the
AT30, AT60 and AT100.

Underground Construction - September 2018

Table of Contents for the Digital Edition of Underground Construction - September 2018