www.engineeringnews.co.nz 39 EN144 • Two pairs of RCH-306 30-ton single acting cylinders locked together base-to-base projecting force outwards within the hinged frame to provide lowering and positioning force • Two RC-2514 single-acting cylinders locked in the hinge frame to provide lifting and positioning force • Specialised hollow single-acting cylinder to tension MacAlloy bars – used to support the cantilever support section of the main bridge structure • Two pairs of specialised double-acting hollow cylinders used to lower and position each section • An Enerpac ZE3410SE hydraulic electric pump, specified to provide best performance for mid-range cylinders and tools, was used in combination to provide lift and lowering of the launch nose. The ZE pump’s high-strength, moulded electrical box protects electronics, power supplies and LCD readout and stands up to harsh industrial environments such as this An Enerpac PUJ-1201E hydraulic electric pump with two-speed pump operation for reduces cycle times and improved productivity was used in combination with Enerpac low-profile lock ring cylinders used to take up load on cantilevered sections. The low-profile cylinders – part of a range designed to fit compactly into confined spaces – were selected to ensure optimum mechanical load holding safety. 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 professional bolting technology, 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,” says 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.”
EN-Mar17-Digi
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