De Kooiman Groep in Zwijndrecht, The Netherlands, specializes in repair, modi- fication and construction of ships up to sizes of 135 meters. Located in “Swin- haven” the shipyard offers perfect access to open sea as well as inland water- way transportation. Founded in 1884 directors Rinus Kooiman and his brothers are looking back on long successful history. “With our own design department, carpentry and machinery shop we are capable to perform all tasks from new building to major modifications and from small repairs to complete overhaul” explains director Rinus Kooiman. “Our company is well equipped and up-to- date in regards to hardware such as slipways, modern docks, outfitting keys and lifting capacities”, Rinus Kooiman continues “But for the repair and overhaul of ships we experienced extremely long downtimes. Damaged ships due for repair always had to come over to the shipyard to be repaired (by hand with good craftsmanship). But the downtime for these manual repairs can be reduced much, when you can prepare all parts by modern CAD system and digital cutting machines”. For the Kooiman Shipyard it was time to take the business to the next level.
Peter Vrolijk from Kooiman´s Department of Heavy Industry Ships explains “The vision of the management was to reduce downtime extremely. Therefore it was necessary to give digital input into the recently installed CAD system by making use of advanced 3D measurement techniques”.
Therefore the shipyard started an investigation on the available 3D measuring and scanning techniques available in the industrial metrology market. It was Ingenieurbüro Mühlhoff, a pioneer in the use of 3D design for ship design, which pointed De Kooiman Group to the GOM mbH who`s optical meas- uring systems are globally applied in applications like 3D digitizing, deforma- tion measurements and quality control. The GOM mbH, experienced developers of optical metrology systems, proposed Kooiman to test the TRITOPCMM system, a photogrammetric solution based on a digital camera, markers and software.
“Of course we wanted to invest only in the most suitable 3D measuring tech-nique available. So we were looking at different techniques like Terrestrial Laserscanning and Photogrammetry” describes Peter Vrolijk the challenge of selecting the appropriate system“. We also wanted to make sure that the measurement system is able to perform all our requirements, so we defined a number of challenges for the system” he continues.
1. Besides the task of measuring the outside body shell the selected system needed also be able to perform measurements of small indoor compartments within the belly. The challenge here is to carry out a reliable measurement with only limited space and very short measuring distance available. So the TRITOPCMM system had to proof the capability of measuring dimensions and inner reinforce- ment structures such as sections, ribs, beams and frames of 6 m by 6 m compart- ment behind the engine room just above the propeller area.
2. The second necessity is measurement of outer hulls of complete ships for major reconstruction outside in the dry docks. A 75 meter long bunker ship which serves oil and petrol to other ships in the harbor of Antwerp in Belgium re- quired a second hull shape to fulfill the upcoming EU-laws and safety demands. In order to design the new sections and second hull shape, Kooiman´s engineer- ing office needed the entire shape of the existing hull. The ship had been in the dry-dock for measurement campaign for barely 48 hours, before it went into water again back to normal service. The total downtime was cut by several weeks, making the project much more cost efficient.
Looking at optical metrology, De Kooiman groep’s first intention was to improve the 3D input towards the CAD design office. The use of GOM´s TRITOP system meant also a breakthrough towards efficient and accurate 3D modeling of hull assemblies.