Wuhan Wuchang Shipbuilding – Specialized Workboat Stern Tube Bearing Supply

Client: Wuhan Wuchang Shipbuilding Industry Group Co., Ltd. (WSIG)
Vessel Type: Specialized workboat for offshore operations
Scope of Supply: Forward, middle, and aft stern tube bearings
Application Field: Marine propulsion system
Key Challenge: Long shaft span, low rotational speed operation
Significance: First adoption in offshore specialized workboat segment

The workboat under construction at Wuchang Shipbuilding is designed for a range of offshore duties that demand continuous, dependable propulsion performance. One of the critical technical challenges lies in the shafting system—specifically, the long unsupported span between bearings and the sustained low-speed operation typical of this vessel type.

Conventional oil-lubricated bearings, while common in the industry, introduce two persistent issues: the risk of oil leakage into the marine environment, and the added complexity of sealing and auxiliary lubrication systems. For a workboat expected to operate with minimal downtime and in environmentally sensitive areas, these are not acceptable trade-offs.

The yard and the owner were therefore looking for an alternative that could eliminate lubricant pollution risk while maintaining—or exceeding—the load-bearing capacity and service life of conventional designs.

Our Solution

We supplied a complete set of 3 Techemer elastoplastic alloy stern tube bearings, positioned at the forward, middle, and aft sections of the shaft line.

The bearing arrangement was configured to:

• Support the forward shaft section with precise alignment stability
• Balance intermediate loads to prevent excessive deflection across the shaft span
• Handle the combined radial and thrust loads at the propeller end, where dynamic forces are most demanding

The material choice—Techemer elastoplastic polymer alloy—was driven by the specific operating profile of this vessel. Unlike rubber-based or metallic alternatives, this composite offers a combination of properties that proved particularly suited to the application:

Water-lubricated, with built-in self-lubrication
The bearing runs on seawater, eliminating the need for oil lubrication altogether. This removes the environmental risk and simplifies the shafting arrangement. The internal lubricating microcrystals embedded in the alloy matrix provide an extra layer of protection during start-up and momentary dry-running events, which are not uncommon in actual service.

Low-speed performance
Long shafts at low rotational speeds tend to operate in boundary or mixed lubrication regimes. The material's compliance and edge-load tolerance allow it to accommodate minor shaft misalignment and deflection without localized overloading—a common failure mode in rigid bearing materials under similar conditions.

Wear resistance that translates to longer intervals between overhauls
In previous installations across bulk carriers and dredgers, the same material grade has demonstrated wear rates substantially lower than those of conventional bearing materials. For a vessel that may spend extended periods away from repair facilities, this translates directly to operational availability.

Reliability backed by certification
The bearings were manufactured under our CCS-approved Works Approval and ISO 9001:2015 quality system. Each unit is traceable through production, and the inspection records are retained as part of the project documentation.

Why This Matters

This is not the first time our bearings have gone into a marine application. Bulk carriers, dredgers, and offshore support vessels have been using Techemer bearings for years, and the track record shows consistent performance across a range of operating conditions.

What makes this project notable is the vessel type and the operating environment. Specialized workboats are held to tighter performance margins—failures are costly, and the operational profile leaves less room for compromise. The fact that Wuchang Shipbuilding and the end client selected our bearings for this build represents a practical endorsement of the product's capability at a more demanding tier of the market.

It also reinforces a trend we have been seeing: yards and owners are increasingly willing to move away from oil-lubricated systems where water-lubricated alternatives can meet or beat the performance, particularly when environmental compliance and lifecycle cost are factored in.

Current Status

The bearings have been manufactured, inspected, and delivered to the yard in accordance with the project schedule. Installation was carried out following our standard fit-up procedures, with our technical support available on-site during the critical stages.

Early operational feedback—while still within the initial running-in phase—has been positive, with shafting alignment and running temperatures within expected ranges.

Conclusion

The Wuchang Shipbuilding specialized workboat project confirms what we have been demonstrating across other marine segments: that Techemer elastoplastic alloy bearings offer a viable, often superior, alternative to traditional oil-lubricated designs in demanding propulsion applications.

For future workboat and special-purpose vessel projects, this installation provides a documented reference point—not as a one-off solution, but as a repeatable option backed by actual service experience.