Philanthropist Donates Historic Scraper to Upper Waitaki Display

A historic Terex S24 scraper has been donated by philanthropist and director of Rooney Group, Gary Rooney, to enhance the display of earthmoving machinery used in the Upper Waitaki Power Development. This addition highlights the crucial role that such equipment played in the excavation and material placement for the canals connecting Lakes Tekapo, Pukaki, and Ohau, as well as various dam sites.

The S24 scraper, alongside other well-known models like the Caterpillar 631 and International 295, was instrumental in shaping the landscape for this significant hydropower project. In February 2024, the Rooney Group transported the S24 to Temuka, where it underwent sandblasting and repainting before being officially added to the display in Twizel.

Rick Ramsay, convener of the Heritage Group, expressed enthusiasm about the new addition. “There are a lot of operators who will fondly recall the distinctive roar of these machines,” he stated. “To again see one in the Mackenzie Basin on display is a big addition.” Ramsay commended Rooney’s generosity, noting that not only did he donate the machine, but he also facilitated its transportation.

The Terex S24 scraper is powered by a V12 General Motors two-stroke diesel engine, paired with an Allison CLBT-5865 six-speed powershift transmission, allowing for a top speed of 50 kph. The machine features a bowl capacity of 18 cubic meters struck or 24 cubic meters heaped, making it a formidable tool for heavy earthmoving tasks.

Despite its robust specifications, with over 400 horsepower and a differential lock to prevent wheelspin, the S24 scrapers were typically push-loaded by bulldozers during the Upper Waitaki project. This was largely due to the dense nature of the glacial moraine deposits involved in the earthworks.

Clyde Engineering sold a total of 32 S24 scrapers to New Zealand, mainly for hydroelectric projects. Companies such as Higgins Earthmoving, Earthmovers Waikato, and McBreen-Jenkins are among the fleet operators that employed these durable machines. Rooney himself acquired the construction arm of Doug Hood Ltd around 1998, which included several S24 scrapers.

The specific unit donated to the Twizel display is one of three that Rooney Group purchased from the North Island for their Rangitata South Irrigation Scheme, a private project costing over $130 million. These units were exclusively used for this initiative and were stored at the company’s Ashburton depot after project completion.

The robust construction and ease of maintenance of the Terex S24 scrapers have allowed many to be rebuilt and continue operating in various capacities, even today. Some have been repurposed as “dump trucks,” facilitating efficient material distribution and compaction during construction projects.

With this donation, the historical significance of the Upper Waitaki Power Development continues to be celebrated, preserving the legacy of the machinery that played such a vital role in shaping New Zealand’s hydroelectric landscape.