Rotation gearbox MT5

47 Meters into the bore at The Lodden the rotation gearbox became very noisy. the two hydraulic motors that drive had a distinct bearing rumble and even with no load there was a grinding sound. The rotation box was removed and stripped. We found that the main thrust bearings in the gearbox had suffered water corrosion at some time and the last few days work had just aggravated the problem. Also the hydraulic motors had also suffered bearing damage, causing the seals to start leaking excessively. Parts were no problem and the motors were Rexroth , the gearbox bearings were available. Two days later the rotation box was assembled and fitted to the giant jacking frame that it belonged to. The photos show the size and weight of the parts in question.

Please click on the images to enlarge.










The clip below shows the rotation box in motion and boring away after the repairs.

Power Pack blow out.

The large 3000 cfm Vacuum Power Pack driven by a large Big Cam Cummins motor decided to take a rest. After working hard for days in the summer heat the control valve assembly started leaking badly. Little notice was taken at the start of the leak , in fact some hoped that it would just go away. This assembly controls the oil flow to the large Roots Vacuum Blower seen in the photo below. Drive by very high oil pressures and with oil temperature reaching the top end of the scale we were forced to shut down and repair the valve block. Confined to a 6m shipping contained this job was cramped , awkward , and very sweaty. The Rexroth hydraulic pumps and there associated parts are a pleasure to work on. With the faulty seals replaced and a good service all was up and going again.

Lesson learned : A stitch in time saves nine. Yes had we been informed when the leak started much expense and time could have been spared.

Please click on any of the photo's to enlarge.

Power pack with Cummins Big Cam motor crambed into 6m shipping container.



Rexroth hydraulic pumps - two banks of two pumps each = 4 pumps.



3000 cfm Roots vacuum blower - great stuff!



The faulty valve bank that created great expense.



All that was needed , these o rings and much time could have been saved.

MT5 980mm Microtunneling Machine Control Box.

While Sub-contracting for Leed Engineering on their large tunneling project on the bendigo mains water line the control box on the largest micro tunneling machines gave up. Power drivers that control the steering and camera failed. After stripping down and blowing all the dust out of the circuit boards the problem power transistors were identified. Replaceing did not realy last long as they blew again. Much time was spent tracing the fault down to a Milspec coupling that had been damaged by a bit of rough handling. After this was replaced , along with a new set of power transistors we were back in action.

Lesson learned : Although we work with heavy and large equipment , there are parts that need to be treated delicately and with much care.

Control box shut down - notice the gaping hole which we covered up to stop dust form getting into the electronics.



4 Silver and 4 Black power transistors that were replaced.



Faulty Milspec coupling that started all the problems



Control box ready for action - dust problem also solved.

1200mm Bores Head TBM

Preparation for a bore with this 1200mm Bores Head along with the Brivinni Pipe Jacking Station. All controls and gearboxes checked. Hydraulic cylinders extended and retracted - pressure tested and jacking tonnage calculated.The photos of the Bores Head below show the head after pipe jacking was completed. The Brivinni jacking station is cleaned up and ready for sale to Leed Engineering.

1200mm Bores Head



Inside view



Control System Veiw



Brivinni Jacking Frame ready for delivery.