Terex S24 Scraper Donated to Enhance Upper Waitaki Exhibit

A significant addition to the Upper Waitaki Power Development display has arrived in the form of a Terex S24 scraper, generously donated by philanthropist and director of the Rooney Group, Gary Rooney. This iconic piece of earthmoving machinery, which played a vital role in the excavation and material placement for the canals connecting Lakes Tekapo, Pukaki, and Ohau, is now on display in Twizel, New Zealand.

The Terex S24, alongside other heavy machinery such as the Caterpillar 631 and International 295, was instrumental in constructing the canals that facilitated the development of significant hydroelectric infrastructure, including the Pukaki High Dam and the powerhouse sites at Ohau A, B, and C. Last month, the Rooney Group transported the S24 to Temuka, where it underwent sandblasting and painting before joining the exhibit.

Historical Significance of the S24

Heritage Group convener Rick Ramsay emphasized the importance of this addition. “There are a lot of operators who will fondly recall the distinctive roar of these machines,” he said. “To again see one in the Mackenzie Basin on display is a big addition.” Ramsay expressed gratitude towards Rooney for not only donating the machine but also facilitating its transport, highlighting the generosity involved.

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. It boasts a top speed of 50 km/h and features a hydraulic retarder to assist the shoe brakes. With a bowl capacity of 18 cubic meters struck or 24 cubic meters heaped, the S24 has the capability to handle substantial material loads.

Despite its power, with over 400 horsepower and a differential lock to prevent wheelspin, these scrapers were typically push-loaded by bulldozers on the Upper Waitaki project. This was due to the tough nature of the glacial moraine deposits that comprised much of the earthworks.

Clyde Engineering sold a total of 32 S24 scrapers in New Zealand, primarily for use in hydroelectric projects. Notable fleet operators included Higgins Earthmoving, Earthmovers Waikato, and Doug Hood Ltd. Rooney acquired the construction arm of Doug Hood Ltd around 1998, which included these scrapers. Their rugged construction and ease of maintenance have allowed many to be rebuilt and continue operating on various projects to this day.

Legacy of the S24 Scrapers

The scraper donated to the Twizel display was one of three purchased by the Rooney Group from the North Island specifically for the Rangitata South Irrigation Scheme, a private initiative costing over $130 million. These units were exclusively used for this project and have been stored at the company’s depot in Ashburton since their service concluded.

As the Terex S24 joins the exhibit in Twizel, it not only represents a significant piece of machinery but also serves as a reminder of the engineering feats accomplished in the region. The display aims to preserve the heritage of the Upper Waitaki development and honor the contributions of those who operated these machines.