Ever wanted a 500 bhp 4x4 to run around in? Automatic transmission, super single tyres high/low transfer, full ROPS cabin with air conditioning and heating and faster than a Troopy climbing out of a pit. We did and BHP got us to build it.

Just for good measure we also put the engine in the rear, achieved sound levels better than the average sedan on the road while driving and drilling. The rigs can travel from hole to hole with their mast raised and all hydraulic and compressed air systems remaining active to improve productivity. They can drill a 10m single pass hole and move to a new location in less than a minute all with only one man operation.

Each rig has a modified Schramm mast and Schramm rotation head however from there on they are custom built entirely. The full ROPS and FOPS operators cabin was designed and built in Australia including destruction test to prove the prototype.

In addition to the ROPS cab we conducted rig stability testing by attempting to make the rig fall over by raising the jacks on one side to their full travel. Yes we did have a 150 ton crane with a safety wire attached to the top of the mast as a precaution. The rig did not topple although the bottom of the ROPS cab was almost on the ground and the operator was very afraid!

The reason for this testing was to simulate what might happen if a front tyre burst when traveling from hole to hole with the mast up. When the rig was completed we had 5000kg per tyre with the mast down and a full load of fuel and water. With the mast raised the front tyre loads increased however the loading on each front tyre was the same.

Problems with the units? Well training the drill crew with two people in the cab meant that both parties had to be good friends but otherwise the rigs were simple and fast to operate. The driving seat slews 45 degrees to permit the drill controls to be used and allow clear vision of the hole and simply operating the auto transmission selector to allow the rig to walk forward or backwards to the next hole.

A comprehensive safety system that ensures that the drill pipe is out of the hole before the rig can move as well as a lockout system to only allow the rig to move in the lowest gear when the mast is raised.

Three of these units were built and they have proven reliable and popular with the operators but most of all they reduced drilling costs dramatically for the owners.