Renowned for its expertise in large diameter TBMs, pipe jacking and microtunnelling equipment, and more recently larger capacity horizontal directional drilling (HDD rigs), Herrenknecht, in the early part of 2007, launched its Easy Pipe system which, as covered in the T&TI Trenchless Review of 2007, uses retractable/reusable jacking pipes in the tunnelling process to enable product pipe to be pulled into a microtunnelled bore.

Now the company has launched Direct Pipe, which is designed to utilise the power and accuracy of the microtunnelling technique to lay larger diameter, continuously welded steel casing pipes directly into the ground in a single operation.

The accuracy of microtunnelling has long been an established fact within the tunnelling industry and the development of the Direct Pipe method, which is something of a combination of microtunnelling and HDD techniques, was not only based on a need to create of a one-step pipe laying method but also on the provision of an efficient alternative to existing methods.

The technique required was one that was able to minimise the geological risks (e.g: bore-hole collapse that may occur using HDD). With Direct Pipe steel pipelines can now be, for the first time, pipe jacked efficiently and quickly in one process without the need for large target shaft areas for pipe preparation and storage prior to pull-in. The direct installation of the pipeline allows for continuous drill-hole support preventing potential borehole collapse.

The microtunnelling shield is controlled remotely as it would be on any standard microtunnelling installation with the navigation system giving the same level of alignment accuracy over the course of the bore. What is different with this technique has been the development of the Herrenknecht Pipe Thruster, which enables the continuously welded pipe to be used as the jacking pipe to advance the shield through the ground. On arrival of the cutting head at the target shaft it is removed leaving the casing pipe installed awaiting installation of the product pipes or cables.

In a similar vain, that of combining recognised technologies, Perforator has developed a modification to its standard PBA85 guided auger boring machine to enable it to be used like an HDD rig. This new set up enables the rig to be used from its usual start shaft to install a very accurate pilot bore using a monitor, an optical system with CCD camera and a diode target plate. However, instead of using auger casing and excavation to enlarge the bore and install the pipe from the jacking shaft, a modified drive component allows the pilot rods to be attached to a reamer head, which is then pulled back through the bore to open the hole to the correct size and install the pipe from the reception pit end as with HDD operations. The basic PB85 pilot boring system is a compact, multi-purpose thrust boring machine designed for pipe line, house connection and steel pipe jacking installations of up to 610mm o.d., as is the new PBA85V with HDD ability. The basic machine is used in combination with re-usable or lost steel casings. The machine bed and additional extension frames allow the use of casings up to 6m long.

The very specific difference between the standard PBA85 rig and the new PBA85V system is that, on the ‘V’ version, a gearbox normally used in the Perforator PBA150 rig is fitted. This allows the ‘V’ unit to offer double the torque capacity of the basic unit.

The directional drilling unit can be fitted to the system and utilises the twin wall pilot rods of the standard PBA 85 system, which are designed to accept high pressure HDD fluids, to create the initial bore. Subsequently, the high pressure drilling fluids are delivered to special rotary reamers using a purpose built pump tank and mixer unit with a 2,000 litre capacity.

Towing attachments and swivels have been specially designed to work within the PBA85V’s 65 tonnes of pullback capacity to enable the pull-in of the product pipe.

With more than 37 years of experience in the manufacture of auger boring equipment, American Augers has announced the release of the new 36-600 NG Horizontal Earth Boring Machine.

The standard features of the 36-600 NG include: A Deutz F6L914 85kW turbo diesel engine, a Spicer 5 Speed Constant Mesh Transmission, maximum rotary torque of 175,139Nm, and a working range from 305 to 914mm casing diameter.

The ‘next generation’ design benefits claimed for the machine also incorporate the Quik Tran fast return system, available exclusively from American Augers, as it provides up to 4.5t of push/pull at high speed, and the Quik Split design feature that allows the machine to be separated into sections for faster and easier lifts into and out of the working pit.

Operators of the 36-600 NG will also enjoy an increased ability to pull auger, steering rods, and push product, improved visibility to the master pusher, low centreline and wide stance that provides substantial machine stability.

As well as the 36-600 NG, American Augers also recently introduced the 84/96-1300 NG system designed to bring a greater combination of working diameter and maximum power to the auger boring market. The main advantage of the 84/96-1300 NG is that it will allow contractors to perform larger diameter installation projects a much lower cost, and achieve success with projects that were only possible before with costly microtunnelling machines.

The standard model is designed with a 223kW Caterpillar C-7 Tier III Diesel Engine, and a seven-speed Eaton T14607A Transmission. These features provide the machine with 5,777kN of maximum thrust, and 304,079Nm of maximum torque. The 84/96-1300 is also equipped with a 125mm hex, and has a working range of 610 to 2,438mm.

HDD

Developments have also continued apace in the Horizontal Directional Drilling field. For example, Swiss manufacturer Terra has developed a new Horizontal Directional Drilling (HDD) machine the TERRA-JET 7520 D, which claims to set new standards in the 20t HDD rig class.

The TERRA-JET 7520 D has the capability to install directional bores of up to 400m long and 800mm diameter, depending on ground conditions. Due to the low engine speed, of only 1,850rpm, the machine has a ‘supersilent’ operation. The machines torque and pullback force are produced by separated hydraulic circuits. Therefore the maximum torque of 7,750Nm and the maximum pullback force of 195kN can be used simultaneously under full load. The multifunctional joystick activates during back reaming and pipe pulling, with the TERRA-JET 7520 D being equipped with a new second generation ADBS. This patented Automatic Drilling and Backreaming System (ADBS) automatically adjusts the machine’s working speed within milliseconds in relation to the prevailing ground conditions. The drilling fluid volume is 185 l/min at a maximum fluid pressure of 85 bar. Optionally the drilling fluid volume may be increased to 370 l/min. The machine’s rod changer allows very fast drill rod changes with one rod magazine holding 120m drill rods.

Also in the HDD sector, Tracto-Technik recently launched the new GRUNDODRILL 15N HDD rig which incorporates a powerful combination of the TT Group’s latest technology and worldwide user experience. Precision engineered, the GRUNDODRILL 15N’s rigid construction easily handles its 7,000Nm of available torque and 167kN of thrust and pullback. During the drilling process the rig can be quickly configured using the touch screen control and provide all functions with the required power, to suit the toughest ground types, up to the maximum values given.

The GRUNDODRILL’s dynamic impact unit, provides an additional percussive impact value of 28t at a frequency 0-1,500 impacts per minute. This unique patented TT feature provides fast, accurate drilling in the hardest of ground types.

A facility on the GRUNDODRILL 15N automatically identifies a full or empty bay in the drill rod box which is advanced accordingly. Both the rod loading and connecting of the drill string are fully automatic. The rod box has the capacity to store seventy (70 No) 3m long drill rods, to give a working distance of 210m. From a pilot bore of 115mm diameter, pipes up to a diameter of 500mm can be installed, subject to ground conditions, with 300m bore lengths being possible.

With the rig’s extremely slim profile, just 2m wide, and variable mast angle inclination, from 0° to 30°, drilling is possible in the tightest locations. The drill stem axis is positioned 900mm in from the side, to allow drilling work in close proximity to walls or hedgerows, etc. The drilling process is controlled via twin multifunction joysticks positioned to operate and control all functions whilst settings and real-time values are monitored on the GRUNDODRILL’s space saving colour display function screen. Remote, real-time telemetry, diagnostic and service menu operator support is a standard feature.

In the USA, American Augers has had a busy year with the launch of several new drill rigs, auger borers and mud handling systems. Included in the recent product releases has been the DD-440T Maxi-Rig, which is being claimed to bring a new era in track driven directional drilling.

The DD-440T provides 200t of maximum thrust/pullback, and utilises it with excavator track driven mobility. The carriage system provides, a rack and pinion, two pinion drive with adjustable force limiter. The state-of-the-art rotary system includes a three pinion and gear drive with infinitely variable torque, up to 80,000Nm of maximum rotary torque, a rear mounted mud swivel that provides up to 2,460 l/min flow, slip spindle, and a 75mm fluid course.

Other standard features include: 10°-18° drill angle, triple jaw wrenches with a 305mm separation, wrenches that travel the full length of the thrust frame, 200kNm of maximum breakout torque, 136kNm of maximum makeup torque, H-Beam type front and rear safety hold down system with struts, removable wrenches for lighter transport weight, and the ability to utilise Range II drill pipe.

A further addition to the range is the DD-880. This large maxi-rig style for horizontal directional drilling is very well suited to perform large diameter, or long length pipeline and utility installation projects.

The DD-880 provides a maximum 400t thrust/pullback capability as well as up to 136kNm rotary torque. The Standard unit is equipped with a four (4) rack and pinion carriage drive system with adjustable force limiter, 100mm diameter fluid course for increased down hole hydraulic power, triple jaw wrenches with 300mm separation, and a maximum carriage speed of 40m/minute.

Also recently designed, manufactured and launched by American Augers is the new DD-9014 HDD rig, which is a self contained drilling system that features a field-proven design, mobility and flexibility, on the toughest trenchless projects all over the world. According to American Augers the machine brings with it performance, durability, and low down time, the keys to profitable operation.

The standard DD-9014 offers what is claimed to be the best design in mid-size HDD engineering, as this unit comes with a Caterpillar 230 HP (171.1 kW) C-6.6 Tier III Diesel Engine, 40.8t maximum Thrust/ Pullback, Rack and Pinion, (4) Pinion Carriage Drive with Adjustable Force Limiter, and 18,300Nm maximum Rotary Torque, which allows the machine to turn larger size reamers on long distance bores.

The company has also launched the P-500 G2 mud pump, which is a stand alone mud system designed for use with mud motors, large reamers, or whenever more mud volume is needed down hole. Standard features are a Caterpillar C-15 475 HP diesel engine, and a mud pump that has an estimated output of some 1,892.5 l/min flow at 105.5 bar.

The Ditch Witch organisation also announced a significant upgrade to two of its most rugged and powerful horizontal directional drilling (HDD) machines: the JT4020 Mach 1 and JT4020 All Terrain.

Both units are now equipped with a welded, double rack-and-pinion thrust drive system designed to withstand the rigours of long bores in tough soils. This new feature further enhances the reputation of these compact workhorses as some of the most durable and productive in their class.

The rubber-track mounted JT4020 Mach 1 features a 4.5m drill pipe, and has the power and stability to pull multiple conduits up to 305m in a single pass, assisted by a cruise-control feature that maintains thrust and rotation settings.

The JT4020 Mach 1 also features touch-sensitive, variable-speed, electric-over-hydraulic controls that minimise operator effort, with thrust/pullback and rotation controlled by a single lever.

The JT4020 All Terrain has patented features such as a two-pipe rock-drilling system and an integrated electronic system with cruise control, the 142kW JT4020 All Terrain can efficiently install utilities underground at long range, up to 305m.

The company has also broadened its range of guidance systems and bit ranges with the introduction of the 250R/T locating system and the 720ML New Magnetic Locating System.

Replacement systems

One of the most utilised bursting ‘system types’ systems is the hydraulic pipe bursting rig, which utilises a pipe pushing/pulling unit to pass a steel rod through the existing pipe from a launch pit to a target pit positioned at either end of the pipe being replaced. One drawback of such systems is that occasionally the broken shards from the old pipe cause damage to the new pipe as it passes through the void created.

To address this situation Perforator of Germany, along with its UK subsidiary, has introduced to the pipe bursting market two new bursting rigs, the RBZ60 and the RBZ160 with pullback capacities of 600kN and 1,600kN respectively.

Working in exactly the same way as traditional hydraulic rod-based pipe bursting systems, the major difference between the new rigs and the old style ones is that, using an independent grout injection system, a cement grout mix is pumped under pressure through a feed line inside the new replacement pipe via ports in the expansion head that are positioned to ensure the grout is uniformly placed around the new pipe as it is towed in.

The grout combines with the old pipe shards and the mix is pushed into the surrounding ground, cementing the shards into place. This avoids interaction between the shards and the new pipe so reducing the likelihood of damage to the newly installed pipe during the pull-in operation.

So as was hinted at previously, in a quest for ever improved performance at the most economic outlay, developments in the installation and replacement sectors of the trenchless technology industry have yet still to peak.


The new combination pilot auger/HDD rig from Perforator The new combination pilot auger/HDD rig from Perforator A schematic of the Direct Pipe installation technique recently developed by Germany’s Herrenknecht Direct Pipe installation technique The TERRA-JET 7520 D is the latest addition to the range of HDD systems manufactured by Terra TERRA-JET 7520 D The new 84/96-1300 NG auger boring system from American Augers 84/96-1300 NG auger boring system The GRUNDODRILL 15N is the latest HDD rig to be brought to the market by Tracto-Technik GRUNDODRILL 15N Ditch Witch has recently upgraded both the Mach 1 and All Terrain versions of its well-established Jet Trac JT4020 HDD rigs Jet Trac JT4020 HDD rig Perforator has developed self grouting pipe bursting equipment to minimise the interaction between the new pipe being installed and the old pipe shards that remain in situ Perforator has developed self grouting pipe bursting equipment