For almost three decades, Vesconite Hilube bushings have been the trusted components at the rotational heart of automatic water-control gates deployed across various African countries, including South Africa, Namibia, Eswatini and Zimbabwe. This sustained, cross-border track record underscores the reliability of Vesconite bushings in one of the most demanding bearing applications in water infrastructure: gates that must operate unattended, without electricity, for decades at a time.
The gates in question are TOPS (a non-electromechanical water-control technology), designed and supplied by South African company Amanziflow Projects (formerly Flowgate Projects). TOPS gates open and close automatically in response to rising and falling water levels, with no reliance on electrical power or human intervention, which is a design philosophy that places enormous, sustained demand on the bearings at each gate’s rotational axle.
Belfast Dam: 29 years and counting
The longest-running example is at Belfast Dam in Mpumalanga, South Africa, where Vesconite Hilube bushings were installed at the gate axle interfaces in 1997. Now 29 years into service, the installation remains operational and continues to be a benchmark for long-term bearing performance in submerged, low-maintenance conditions.
Namibia: automatic flood response at Avis Dam
That same trusted design was used at Avis Dam near Windhoek, Namibia, where two 11 m by 3.5 m TOPS gates were fitted with Vesconite Hilube bushings at the axle in 2002. The site’s remoteness, unreliable power supply, vandalism risk and harsh environment ruled out electrical gates, making the self-lubricating, maintenance-light nature of Vesconite bearings central to the solution. In February 2004, the gates opened automatically to pass an estimated 1-in-50-year flood, then closed automatically to restore the full supply level in a real-world demonstration of Vesconite-equipped gates performing exactly as intended, unattended, under pressure.
Eswatini: engineered for an unusual challenge
At Mnjoli Dam in Eswatini, Vesconite Hilube bushings support the pivots of six TOPS gates on the auxiliary spillway, plus a further gate on the service spillway. These gates were introduced in 2007 after cyclone-driven flooding breached the dam’s original fuse-plug emergency spillway, causing severe downstream erosion and underlining how Vesconite-equipped gates have been called on to solve serious, site-specific water-management problems across the region.
Zimbabwe: frequent operation, sediment-laden flows
At the Runde River Weir in Zimbabwe, a 12 m TOPS gate fitted with Vesconite Hilube bushings operates automatically and frequently, opening to pass sediment-laden floodwater and closing as levels fall, allowing the weir to refill with clearer water. This high-frequency duty cycle is a further test of bearing durability that the Vesconite-equipped gates (installed in 2005) continue to meet.
A regional record of reliability
Across Belfast, Avis, Mnjoli and Runde, and other sites, the common thread is a bearing interface that must rotate reliably after long periods of inactivity, withstand substantial loads, and resist water ingress without external lubrication or regular servicing. Vesconite bearings are engineered for exactly this: they are self-lubricating, offer low-friction operation, and exhibit low water absorption and strong dimensional stability in submerged service.
