A vessel assembly system is a 3D CAD modelled set of components for the structure and plating of a boat, that arrive at the yard pre cut and formed to shape ready for assembly – essentially Airfix for boats.
Deri Jones & Associates Ltd (DJA) has designed the assembly systems for many of the boats constructed by Parkol and work with them to continually improve the system. With the introduction of the LS880 subcontract scanning service by Geospatial Survey Solutions Ltd (GSS) and DJA, an investigation was carried out to compare the accuracy of the constructed steel hull with the original design model. The LS880 was used to capture the hull surface of the Copious, a 19m trawler destined for Shetland. With the complex curved nature of a boat, a laser scanner is the ideal tool to measure the shape accurately. It also allows a vast amount of additional detail to be captured, weld seams where plates are joined, distortion due to welding and the captured data is a truly accurate "as built” image of the boat. The scan data was transferred to DJA’s CAD workstation and unwanted data such as false reflections from the steel dust in the air (a common hazard in heavy steel construction yards), the surface of the river and launch crane were removed in FARO Scene.
The required area of the bow, where the majority of distortion was expected was exported to 3D Reshaper, a CAD package capable of handling large point cloud files and IGES CAD data. In Reshaper, the scanned hull data was aligned to the original 3D CAD model and a point to surface comparison calculated.