In 1977, Vesconite Bearings achieved its first success in a marine application on the RP Jackson, a hard-working pilot vessel operating in Durban Harbour, South Africa.
This landmark application marked the beginning of Vesconite Bearings’ success in marine propulsion systems, and, nearly five decades later, it remains a key proof point of Vesconite’s durability, performance and wear resistance.
In 1977, the 104-gross-tonnage RP Jackson underwent a trial installation of Vesconite in its A-frame propeller shaft bearings. The starboard-side A-frame was fitted with a Vesconite bearing, while the port side retained a conventional rubber-type bearing, allowing a direct in-service performance comparison under identical operating conditions.
Each of the vessel’s propeller shafts transmitted up to 525 kW (700 BHP) at an average of 400 RPM. The Vesconite bearing, measuring 550 mm (21.7″) in total length and with a wall thickness of approximately 20 mm (0.78″), was supplied in two sections, interference-fitted into a brass sleeve, and retained with a mechanical keeper and Loctite retaining compound for secure placement and vibration resistance.
To accommodate water flow and lubrication, longitudinal U-shaped grooves, which measured 11 mm (0.43″) wide and 2 mm (0.08″) deep, were machined along the full internal length of the bearing.
The RP Jackson operated between 12 and 16 hours daily, often under variable speeds and loads, and encountered suspended sand particles in the water. Despite this, the Vesconite bearing showed remarkable resilience over a five-year operational period.
In September 1982, the propeller shafts were removed for inspection—the first since the Vesconite bearing had been installed. Upon removal, it was noted that the shaft bearing area was highly polished and showed minimal signs of wear. This observation underscored the bearing’s low-friction properties and wear resistance.
Precise measurements confirmed the bearing’s outstanding wear characteristics. The Vesconite bearing originally had an inner diameter of 145.64 mm (5.734″). After five years of continuous use, the diameter increased only marginally to 147.14 mm (5.793”), representing a total wear of just 1.50 mm (0.059″). The corresponding stainless steel shaft showed similarly low wear, with the diameter decreasing from 145.14 mm (5.714″) to 144.91 mm (5.705″), indicating only 0.23 mm (0.009″) of wear.
No accurate wear data could be obtained from the port-side rubber bearing due to a lack of initial measurements and the irregular, uneven wear observed on removal. However, the contrast in condition between the two bearings led to a decisive recommendation.
Following this performance review, Vesconite was installed on both the port and starboard A-frame housings of the RP Jackson. The decision marked the first full conversion to Vesconite for propeller shaft support in a marine vessel and solidified Vesconite’s credibility in marine bearing applications.
Vesconite Bearings CEO Dr Jean-Patrick Leger reflects on the significance of the project: “The RP Jackson installation was a breakthrough moment. It demonstrated that our technology could not only compete with but outperform traditional rubber Cutless bearings in marine environments. The data gathered during those five years set the foundation for Vesconite Bearings’ expansion in the global marine sector.”
Vesconite propeller shaft and rudder bearings are trusted worldwide in pilot vessels, fishing trawlers, patrol boats, ferries, yachts, tankers, container vessels, and bulk carriers.
The company’s proprietary materials are appreciated for their dimensional stability in water and excellent wear characteristics.
