November/ December 2021

INTEGRATED SYSTEMS 54 HYDRAULICS & PNEUMATICS November/December 2021 www.hpmag.co.uk Push-Pull system constructs world’s largest observation wheel An Enerpac Push-Pull system has been used to construct what is claimed to be the world’s largest observation wheel. The Ain Dubai observation wheel is over 250 metres tall, significantly higher than the 168 metre, High Roller observation wheel in Las Vegas, and almost twice the height of the London Eye. Major engineering challenge Constructing the world’s largest and tallest observation wheel is a major engineering challenge at any time. Add in factors such as sandstorms, strong offshore winds, ambient temperatures up to 45C and steel temperatures in direct sunlight reaching 80C, and it’s not difficult to appreciate the task facing Enerpac Heavy Lifting Technology, a specialist in engineering world class hydraulics systems. All at the heart of Bluewaters, the sophisticated, must-visit island destination in Dubai, United Arab Emirates, the ‘Ain Dubai’ observation wheel is big – standing at over 250 metres tall. When tackling construction on a scale never encountered before, Enerpac was able to fall back on over 60 years’ experience. Since the late 1950s, Enerpac has developed construction techniques that are beyond the scope of traditional construction technologies. At its simplest the ‘Ain Dubai’ comprises a wheel rim, rotating hub and fixed spindles mounted on four support legs. The rim is 240m in diameter and assembled from eight segments that are welded together and connected to the hub by cable spokes each longer than a full-size football pitch. For the wheel assembly, the height of the ‘Ain Dubai’ takes it well beyond the reach of a traditional crane and so an alternative method was needed. Enerpac proposed to use a Push-Pull system for the wheel construction. Push-Pull system The concept of the Push-Pull system for the wheel assembly is straightforward enough. Located at the base of the wheel, a pair of hydraulic grippers pushes the wheel forward, effectively rotating it. The push grippers are then released and pulled back into position using hydraulic cylinders. The Push-Pull operation is then repeated. The simplicity of operating Enerpac’s Push-Pull system belies the complexity of the engineering underpinning it. Implementing the concept for ‘Ain Dubai’ meant working to significant project constraints. Aside from the environmental The ‘Ain Dubai’ under construction showing the Enerpac Push-Pull system at the wheel’s base. ABOVE: Showing the Enerpac Push-Pull system in operation. BELOW: Render of the Enerpac Push-Pull system.