SHAFT BRACKETS

When considered as part of the wider sterngear package, shaft brackets (A and P) can play a significant role in maximising your vessel’s performance efficiency. Fully optimised sterngear setups, including brackets designed using CFD, help to reduce water disturbance and drag, and provide a more comfortable ride, with improved performance and greater overall longevity due to reduced cavitation.

CJR’s shaft brackets range from a bore size of 25mm to 180mm diameter – up to a total weight of 600kg. Every set of brackets is designed bespoke, using CFD and FEA design tools to achieve optimum performance and, as a result, offer amongst the lowest total cost of ownership available. This is achieved by taking the time to understand the vessel’s individual requirements and intended application beforehand and collating the data required to deliver a fully optimised solution that meet the customer’s expectations.

With the required data in hand, we build a 3D model for all component drawings and to be used for CFD and FEA analysis. The developed 3D model can be issued to the customer allowing them to import the file into their own 3D hull geometry. This ensures precise and accurate fitting with the hull is achieved before any tooling manufacture begins.

The CFD difference

Through our CFD department, we are able to predict the water flow into the bracket under a myriad of sea states. These complex, fully automated simulations enable us to test and iterate the design and positioning of the bracket and reveal the precise hydrodynamic geometries and strength analysis we need for manufacture.

Once CFD analysis is complete and the design is finalised, the 3D model is then sent to our pattern-less robotic mould-making centre, where the precise bracket shape is machined out of a solid block of sand and resin before being sent to the foundry, ready for the casting procedure.

Fluid dynamics isn’t but it is critical to A low drag areafoil section is applied to all struts ensuring the highest efficiency and performance and lowest vibration level is delivered every time.

Manufacturing

Shaft brackets (A or P bracket/Strut) are typically manufactured from high-grade nickel, aluminium bronze or manganese bronze materials. Cast in our own foundry with the latest technology casting processes.

The casting process is controlled to IACS requirements including material analysis and NDT testing when needed. Most castings are machined on the latest 5 Axis Machining Centres.  Machining in one loading allows CJR to achieve the highest standard of accuracy for alignment of palm mounting to shaft bore. All castings are finished to the highest standard and are fitted with water lubricated bearings which can be IACS approved when required.

Alternatively, all brackets can be fabricated in aluminium, stainless steels, or mild steel as a complete item or component parts.

Installation

Shaft brackets can be bolted into the hull using the palm plate. P struts can be glassed into the hull or alternatively glassed in and bolted through and fittings secured with chock fast. Fitting methods and procedures are to the designer or boat yards discretion.

All components parts can be supplied with fixing bolts and backing plates, strips or washers

Alternatively, all brackets can be fabricated in aluminium, stainless steels, or mild steel as a complete item or component parts.

Each bracket produced under classification society rules is inspected to an IACS approved quality procedure.