STRENGTH AND CORROSION RESISTANCE
Most shafts are manufactured with Marinemet 25 as standard, which is stronger and more resilient to corrosion than even surgical stainless steel. Other materials from 316L up to Super Duplex are available if required.
Generally, materials are sourced from mills specifically chosen by CJR for their quality to meet IACS requirements.
Shaft sizes are available from 30mm up to 180mm diameter and a length of up to 9m. Note that shafts in excess of 6m are not generally kept in stock by CJR or its stockholders, and lead times can be up to nine months.
- Provides not only the machining of the shafts themselves but the full assembly and inspection of our shaft-line products; from bar to dispatch.
- We precision machine fully ground high strength marine propeller shafts using 5 axis machine tools that allow single set-up manufacturing which greatly reduces inaccuracy, unnecessary handling and the total number of operations.
- All shafts leave the works pre-lapped with their respective coupling in order to ensure sound mating taper contact is achieved, which reduces unnecessary fitting time at the vessel.
Shafts can be manufactured for standard tapered keyed connections to: ISO 1:10, SAE 1:16 or BS marine standard 1:12, as well as keyless tapered 1:30. Any other non-standard taper can also be machined.
Every bar from 30 to 180mm in diameter is straightened to a tolerance from 0.005” to 0.02” over a length of up to 9m and 0.005” to 0.01” on taper respectively and is machined in one piece..
This accuracy ensures each shaft is manufactured to deliver vibration free operation.
CJR offers various services and products to assist with the installation of shafts. These include Shaft Alignment Calculation to assess best bearing positions and offsets, a laser alignment system, a hydraulic coupling pusher/puller for quick and simple keyed coupling and propeller attachment, and Propsmith – a mechanical system for easy propeller fitting and removal.
For keyless hub-shaft connection CJR can offer a complete hydraulic fitting kit including hydraulic pushing nut and hydraulic pump to expand the hub.
CJR has developed a trials data acquisition system – TrialsAPP – for the analysis of boat performance. This includes vibration monitoring tuned to the shaft and propeller blade passing frequency. This allows any shaft straightness or mis-alignment problems to be quickly diagnosed without removing the shaft from the boat for inspection.
CJR can replace and retrofit any shaft of any design within the manufacturing range in case of damage.