Microtunnel Boring Machines (MTBMs) install gravity flow pipelines requiring precise line and grade in poor soil. Microtunneling is a non-manned, remote controlled, continuously supported pipe jacking method. Standard MTBMs are sized in the 30-96-in. (762-2,438 mm) OD range. Soil excavation takes place by way of infusing the soil with slurry at the face of the bore where cuttings are forced into slurry inlet holes in the MTBMs crushing cone for circulation to and from a separation plant through a closed system. A complete slurry microtunneling system is comprised of a pipe specific MTBM, control container, remote hydraulic power pack, jacking frame, a series of pumps, laser, water cooling tank, slurry trunk and additional lines, and a slurry separation plant. The launch shaft is outfitted with a pit seal to prevent flooding of the shaft and a project specific thrust block to distribute jacking force. Microtunneling operations are managed by an operator in an above ground control container alongside of the shaft.
Microtunnel Boring Machines (MTBMs) in standard sizes of 30-96-in. (762-2,438 mm) OD, accurately install pipe in virtually any ground condition, especially in high levels of ground water. MTBMs feature high pressure jetting nozzles, an articulated steering joint with three-point steering control, and hydraulically activated dirt wings to minimize MTBM roll. The guidance system relays all critical operation data to the control container using a proprietary Akkerman Machine Control Software Program. Additional MTBM attributes include a live, one-way audio system and camera allowing for system monitoring during operation, gas detector and submersible pump. Standard MTBMs can be outfitted with increase kits for adaptability. The soft ground and mixed ground cutter heads and crushing cones are hard faced to withstand wear and can be customized for specific ground conditions.
The Control Container houses the control console, motor control centers for the slurry pumps, MTBM drive motor and bulkhead panel for electrical and communication connections inside a full size shipping container. Inside the climate controlled cabin, the operator monitors and controls all facets of the microtunneling operation from a two-monitor display and console. Monitoring includes the MTBM’s pitch and yaw, rotation, torque, jetting, jacking thrust, steering, slurry flow and pressure, as well as its anticipated position at the cutter face to the operator in the control container using our proprietary Microtunneling System Software Program. Variable Frequency Drives (VFDs) control the electric motors for the MTBM drive, and feed, return and booster pumps systems.
The Remote Hydraulic Power Pack is a power distribution center for the jacking frame and microtunneling auxiliary functions housed in a BiCon container for simple site transport.
Keyhole Jacking Frames offer a high capacity jacking frame from a 16-24-ft. (4.87–7.3 m) shaft. They feature 800-1,200 tons (726-1,089 t) of thrust capacity to advance pipe with a maximum 102-in. (2,591 mm) OD in 10-ft. (3 m) lengths. Smaller pipe can be used with a thrust adapter. Keyhole jacking frames are configured with and without a dirt bucket bay for pipe jacking and microtunneling applications. Keyed blocks on the hydraulic jacking cylinders continuously advance the MTBM or TBM and a winch is used to retract the cylinders.
The High Pressure Jetting Pump provides high velocity jetting to the cutter face to break down clays and silty soil, cleans the crushing chamber and assists with soil intake and flow.
Feed and Return Pumps help the slurry system circulation to and from the slurry separation plant. A Booster Pump is used to assist slurry return from the MTBM through the tunnel.
The Water Cooling Tank and cooling pumps keep the drive motor cool, flushes seals and features a 1,685 gal (6,378 L) capacity supply.
Slurry Trunk Line is welded in 10-ft. (3 m) lengths for fluid passage for bentonite, slurry feed, cooling and slurry return flows. Slurry trunk line is positioned in the base of each section of pipe, and connected before jacking occurs.
The Microtunneling Guidance System includes an active target and three inclinometers that read and transmit data to the control console screen in the control container. Two inclinometers in the target and one at the rear of the MTBM track roll and incline while tracking redundant data to ensure accuracy. Another inclinometer is mounted in the front of the MTBM assesses the incline. The proprietary Microtunneling System Software Programs display the target data’s current and projected cutter head location, MTBM incline and roll to the operator’s control console. The Microtunneling System Software Programs features data logging and report generation capabilities.
MT460 Microtunneling Jacking Frame Description: This 400-ton jacking frame can be used with up to 62-inch OD pipe in up to 20-foot lengths. The MT460 comes with two 6-foot extension frames, one flat back adapter (not pictured) and one starter hose set (100-foot, not pictured). The MSRP for this unit is $274,600. Serial Number: FA12670F1/FA12737F1/FA12737F2 Selling Price: $150,000 For More Information: 800.533.0386 or e-mail
AKKERMAN PRODUCT GUIDE
Keyhole Jacking Frame Specifications
High Pressure Jetting Pump Specifications
Feed, Return, Booster Pumps Specifications
Water Cooling Tank Specifications
Slurry Trunk Line Specifications