A significant addition to the Twizel Heritage Machinery Display has been made with the introduction of a Terex S24 scraper. This machine was generously donated by Gary Rooney, director of the Rooney Group. The display showcases various earthmoving equipment that played a crucial role in the Upper Waitaki Power Development.
The Terex S24 scrapers, alongside models like the Caterpillar 631 and International 295, were instrumental in excavating and placing materials for the construction of canals linking Lakes Tekapo, Pukaki, and Ohau, as well as the Pukaki High Dam and several powerhouse sites, including Lake Ruataniwha Dam and Tekapo B, Ohau A, B, and C.
Last month, the Rooney Group transported the S24 to Temuka for sandblasting and painting before its official unveiling at the display. Rick Ramsay, convener of the Heritage Group, expressed enthusiasm about the new addition, stating that many operators will fondly remember the distinct sound of these machines. He added that seeing one displayed in the Mackenzie Basin is a significant enhancement to the exhibit.
The S24 scraper is powered by a V12 General Motors two-stroke diesel engine, paired with an Allison CLBT-5865 six-speed powershift transmission, enabling a top speed of 50 kilometers per hour. The transmission features a hydraulic retarder that aids the shoe brakes. The bowl capacity of the S24 is 18 cubic meters struck or 24 cubic meters heaped.
Despite its robust performance with over 400 horsepower and a differential lock to prevent wheelspin, the scrapers were typically push loaded by bulldozers during the Upper Waitaki project due to the dense nature of the glacial moraine deposits involved.
In total, Clyde Engineering sold 32 S24 scrapers in New Zealand, primarily for hydro schemes. Notable fleet operators included Higgins Earthmoving, Earthmovers Waikato, McBreen-Jenkins, Burnetts Motors, and Doug Hood Ltd. Gary Rooney acquired the construction division of Doug Hood Ltd around 1998, which included the S24 scrapers. Many of these machines were rebuilt and have continued to be operational on various projects due to their rugged design and ease of maintenance.
Some S24 scrapers were repurposed as “dump trucks,” utilizing their bowls for easy loading by diggers and smooth material distribution, which provided some degree of compaction. The specific unit donated to the Twizel display was one of three purchased by the Rooney Group from the North Island for their Rangitata South irrigation scheme, a substantial private investment exceeding 130 million dollars. These units were exclusively utilized for this project and have since been stored at the company”s Ashburton depot.
