Propulsion Shaft Alignment, Jacking Load, Bearing Load & Stern-Tube Oil-Film Risk Tool
Propulsion Shaft Alignment, Jacking Load, Bearing Load & Stern-Tube Oil-Film Risk Tool
Compare measured jacking with approved shaft-alignment reactions, check bearing unloading and projected pressure, evaluate cold-to-running reaction shifts and relative slope, screen aft-bearing hydrodynamic lubrication, and price a likely alignment or stern-tube intervention.
Aft Stern-Tube Bearing Quick Screen
Use approved alignment criteria and the actual jacking procedure. The oil-film speed input should come from approved class/maker/design analysis.
Propeller & Running Condition
Shaft Segments
Segments start at propeller center x = 0 and run forward. Self-weight is calculated from geometry and density.
| Segment | Length m | OD mm | Bore mm | E GPa | Density kg/m³ |
|---|
Bearing Register
Aftmost bearing is the smallest x. Running Δ is hull/thermal vertical movement relative to cold.
| Bearing | x m | Cold offset mm | Running Δ mm | Length mm | Journal mm | Bearing slope mrad | Measured jack kN | Jack factor |
|---|
Alignment Acceptance Criteria
Aft Stern-Tube Hydrodynamic Oil-Film Screen
Uses a transparent classical Sommerfeld index. It is not DNV's proprietary lubrication criterion and does not calculate local contact pressure or minimum film thickness.