Downer’s custom-engineered steel bridge launching nose, features a bespoke design controller. This was developed in partnership with Downer and Jonel Hydraulics to maximise safety when launching bridge sections over the Ongarue River as part of a major KiwiRail infrastructure project.
The new Ongarue Bridge launch nose controller, was a feature of a seven-bridge project involving a host of other Enerpac bolting, pumping, heavy lifting and positioning and fine control technologies available throughout Australasia and globally.
"Safety was a keynote of the entire project, extending over nearly five years. The longitudinally launched Ongarue bridge sections posed unique challenges in this regard, compared with the rest of the bridge launches, which were lateral launches involving shorter distances," says Jonel Business Development Manager Mr Shane Quigley.
Downer and Jonel worked through a range of pivot positions and leverage points to ensure precision guidance and placement of bridge sections, employing the cantilevered nose incorporated in a bolted steel frame driven by Enerpac Hydraulics.
The entire launch, tension, position and lowering systems developed by the partnership comprised:
Low-pressure double-acting cylinders were used to launch bridge sections longitudinally from the launching bed, with rollers being used in five positions over the launch series.
Bridge sections involved in the entire seven-bridge project were assembled using Enerpac bolting tools, which demonstrated outstanding safety over more than 250,000 torque cycles requiring high precision and repeatability.
An energy-saving new generation Enerpac ZU torque wrench pump, specified for high-cycle maintenance tasks, was used to actuate the S1500 and S3000 wrenches used for the tasks involved.
"Operators found our Enerpac auto cycle feature torque pumps indispensable, speeding up the whole job with high flow output and by allowing operators to focus on the final bolt head position," said Mr Quigley.
The five other bridges in the project besides the Ongarue bridge (at Whiritoa, Taringamotu, Opotiki, Mangakahikatea, and Waihuka) – used low-pressure double-acting cylinders to launch sections by sliding them sideways from beams to falsework. Enerpac RC-506 standard cylinders were used in this operation to aid removal of sliding beams and to adjust bridge longitudinal positioning during the sliding and final placement. The safe and reliable workhorse single-acting RC cylinders were also used to lower the bridge onto bearing pads.
"Reliability of the equipment was outstanding too. Enerpac all-steel torque wrenches are known for durability and the Enerpac name is a byword for safety and reliability. All the equipment we supplied for the project worked seamlessly, without interruption. We ensured spare components were available if needed, but everything functioned correctly without breakdown."
"The investment in planning preparation and precision execution was essential because this is a key public infrastructure building project, with benefits that will extend decades into the future. Not only were we concerned to ensure that worksite safety was observed in bolting operations on the day, but equally that the finished bolted product was the best of its type, engineered for outstanding future reliability."