Shaft alignment, measured with one instrument, not two
Hexagon provides one measurement solution for positioning and inspection, keeping critical shipbuilding structures on a shared centreline without three point approximations or scaffolding.
Propulsion shaft alignment is one of the highest-consequence measurements in the build
The engine foundation block, propeller nozzle, and stern tube are often built independently, by different suppliers and in different locations, but ultimately must align to one shared centreline. Today’s typical workflow uses two separate instruments for two separate jobs: a total station for positioning large fabricated structures and a laser tracker for high-accuracy inspection of machined components. Lloyd’s Register put the cost of a misalignment-driven stern tube failure at “well in excess of $250,000 per incident for a small vessel”, rising above $1 million where a bent shaft must be replaced on a larger one. Those are 2005 figures; hull claims costs per vessel now run 33% above pre-Covid levels and are projected to rise a further 20% over five years.
Hexagon combines both jobs into one workflow
Two jobs, one instrument, one coordinate frame
A total station for positioning large fabricated structures and a laser tracker for inspecting machined components, replaced by a single instrument — removing the registration step between two coordinate frames, and the error it introduces.
Form error measured, not assumed
The propeller nozzle is scanned across its whole surface rather than characterised on three discrete points, so form error between them is measured rather than assumed.
No scaffolding to reach the hull
Hull attachment points are reached without access equipment, taking out the cost, the programme time, and the working-at-height exposure.
The technology this workflow runs on
One Hexagon instrument covers both the positioning and the inspection. Our software plans the measurement, computes the alignment, and runs the virtual assembly before anything is lifted.
Explore all of the measurement technologies for the yard
FAQs
The centre of a bore is calculated, not measured. A laser tracker and a 6DoF probe take a series of points around the inside of the bore, and the software fits a circle or cylinder to them to give the centre, or the axis. The tracker follows the probe body, so the tip can reach points the tracker itself cannot see.
The values differ per hull, the method does not: flexible hull, stiff shaft, sub-millimetre bearing offsets, the same on large container ships, bulk carriers and VLCCs.
No. The hull still moves with the sun. What changes is how much of the shaft line you capture, and compute, inside the quiet hours.
No. Geometry and bearing load are separate checks: the measurement establishes the geometry, the jack load test confirms the reactions afloat.
One coordinate frame for the whole task – bore centrelines, the installed running line, coupling flange faces and engine-foundation flatness – instead of one tool per task.