TerraRoc PPD 120 Utility Power Pole Drill, 12.25 to 24 in Rock Sockets

The TerraRoc PPD 120 Utility Power Pole Drill is a truck-mounted down-the-hole drilling system built for one job: cutting clean, straight pole sockets in solid rock. It hangs from the utility derrick you already own, runs on compressed air, and produces a finished socket from 12.25 in to 24 in diameter, 84 in deep as standard and 156 in deep with the 72 in extension rod.

Why a DTH pole drill beats augering and blasting in rock

TerraRoc puts it plainly: the PPD 120 drills sockets in solid rock faster and more efficiently than either auger drilling or blasting. That is the whole case for the machine.

Augers work until they reach competent rock, and then they polish it. The crew burns hours on refusal, swaps to a rock auger, chips teeth, and still finishes with an oversized ragged hole that needs more backfill and more compaction. Blasting gets through the rock but brings permits, a licensed crew, exclusion zones, vibration monitoring near structures, and a schedule that is no longer yours to control.

The PPD 120 avoids both problems. The QL 120 hammer breaks rock by percussion at the bottom of the hole, so penetration rate stays roughly constant whether the formation is weathered or competent. What comes out is a round socket at a controlled diameter, which is exactly what a direct-embed pole or a grouted anchor cage needs.

• Predictable production in granite, limestone, basalt and sandstone where augers refuse
• No blasting permits, no exclusion zone, no vibration survey
• Round, straight, repeatable sockets that cut backfill and grout volume
• One crew, one truck, because the drill works off the derrick already on site
• Viable in urban right-of-way and near existing structures where blasting is not an option

How the PPD 120 is built

QL 120 hammer

The drill is built around the TerraRoc QL 120 down-the-hole hammer. Percussive energy is delivered at the bit rather than through the drill string, so energy loss does not scale with depth and the hole stays straight.

Air swivel and cushion

An advanced air swivel with integrated cushion feeds air to the hammer while damping the percussive feedback that would otherwise travel up into the derrick boom and rotation head. This is what makes the system workable on a utility truck instead of only on a purpose-built drill rig.

Pin connections

The drill assembles and breaks down on pin connections rather than threaded joints, so a crew can change oversleeves, add the extension rod, or pull the hammer for service in the field.

2-5/8 in hex drive

The drill takes rotation through a 2-5/8 in hex drive, the common interface on utility derrick rotation heads.

What your derrick needs to run it

The PPD 120 adapts to most utility derrick platforms, provided the truck brings two things:

• Rotation torque: 6,000 ft-lb minimum
• Hoist capacity: enough to lift and control the assembled drill, which is 2,243 lb bare and up to 4,580 lb with the 22 in oversleeve fitted

If you are not sure your platform qualifies, call with the derrick make and model and we will check the rotation and hoist ratings against the drill before you order.

Air supply: size the compressor correctly

This is the specification that most often gets missed. The PPD 120 is a high-consumption DTH tool:

Working pressure	Air required
100 PSI	804 SCFM
125 PSI	1,028 SCFM

Running the hammer short on air does not just slow the drill down, it starves the percussion cycle and accelerates wear on the piston and the bit. Plan on a 900 to 1,100 CFM class portable diesel compressor matched to the pressure you intend to run. Warthog sells machines in exactly this range, so we can quote the drill and the air together and make sure the pair actually works. See our towable air compressors, or call and we will size it against your drilling plan.

Lubrication is not optional

A DTH hammer run dry will damage the piston quickly, and that stays true even when drilling with water. Water is not a substitute for oil. TerraRoc calls for roughly two thirds of a pint of rock drill oil per hour for every 100 SCFM of air, which at 804 SCFM works out to about 5 to 6 pints an hour, and they recommend doubling it for wet drilling above 2 gpm. Many crews meet this with a standalone aftermarket oiler; the factory answer is the support module, which handles oil, dust suppression water and pressure control in one package.

Hole size and oversleeves

The drill covers finished sockets from 12.25 in to 24 in. For diameters above 17.25 in TerraRoc offers oversleeves, also called accelerator shrouds, which fit over the hammer and help stabilize the drill in the hole so the string stays centered and the socket stays plumb.

Oversleeves are optional. Whether you need one depends on your ground and your setup. Crews drilling straight, competent rock routinely run a large bit without an oversleeve. They earn their keep in broken, fractured or loose ground where the string wants to wander, and on deeper sockets where a small deviation at the collar becomes a large one at the bottom. Size by finished hole diameter:

Finished hole	Oversleeve	Part no.	Sleeve OD	Added weight
12.25 in to 17.25 in	None needed	n/a	n/a	Drill only, 2,243 lb
Over 17.25 in	16.75 in oversleeve	52354589	16.75 in	1,080 lb
Over 20.50 in	20 in oversleeve	89010038	20 in	1,790 lb
Over 22.50 in	22 in oversleeve	89010040	22 in	2,337 lb

Maximum finished hole size is 24 in. Not sure whether your ground calls for an oversleeve? Call (888) 229-9904 and we will talk it through before you buy one.

Drilling depth

Configuration	Depth
Standard PPD 120	84 in (2.13 m)
With 72 in extension rod	156 in (3.96 m)

84 in covers the majority of distribution pole sockets. The 72 in extension rod (part no. 51792232) is the answer for transmission structures, deeper embedment specifications, or anywhere the engineer calls for more than seven feet of rock socket.

Optional support module

The support module (part no. 51776011) is a single skid that adds the functions a production pole crew tends to want after the first week:

• Hammer lubrication, metered automatically into the air line
• Water injection for dust suppression, which matters for silica exposure compliance and for visibility on the hole
• Air valve for collar and drill pressure control, so the operator can collar the hole gently and then come up to full pressure
• Remote control box, moving the operator back from the hole

Technical specifications

Specification	Value
Model	TerraRoc PPD 120
Product number	52354523
Configuration	Percussive pole drill with air swivel and 2-5/8 in hex drive
Hammer	TerraRoc QL 120 DTH
Outer diameter	11.21 in (284.7 mm)
Overall length	118 in (3,000 mm)
Minimum hole size	12.25 in (311 mm)
Maximum hole size	24 in (609 mm)
Drilling depth, standard	84 in (2.13 m)
Drilling depth, with extension rod	156 in (3.96 m)
Rotation torque required	6,000 ft-lb minimum
Air required at 100 PSI	804 SCFM
Air required at 125 PSI	1,028 SCFM
Weight	2,243 lb (1,017 kg)
Drive	2-5/8 in hex
Connections	Pin
Mounting	Utility derrick, truck mounted

Drill bits

The bit is the wear item and the one part you cannot skip. TerraRoc DTH bits for the QL 120 are available across the full 12.25 in to 24 in range in a variety of face and button designs, matched to pole diameter and rock condition. Tell us the finished socket size and the formation and we will specify the bit along with the drill.

Accessories, consumables and spares

Item	Part no.	Weight
16.75 in oversleeve	52354589	1,080 lb
20 in oversleeve	89010038	1,790 lb
22 in oversleeve	89010040	2,337 lb
72 in extension rod	51792232	1,051 lb
Support module	51776011	580 lb
PPD 120 air swivel	89010041	Call
QL 120 hammer with PPD backhead	89010205	Call
QL 120 sustainability kit	52354648	Service kit

Documentation

Download the TerraRoc PPD 120 brochure and technical specifications (PDF)

Ordering and freight

The PPD 120 ships as freight from TerraRoc USA. Warthog Air Compressor Store handles order placement, freight coordination and warranty registration. Call (888) 229-9904 for current lead time, freight to your yard, and compressor pairing. If you are drilling to a utility specification, send us the embedment detail and socket diameter and we will confirm the bit, and whether you need an oversleeve, before the order goes in.