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Improving Global Quality of Life
Through Optimum Use and Innovation of Welding and Joining Technologies
This situation is unsatisfactory and is threatening the survival of the shipbuilding industry inmodern societies.
Delayed transition into modern technological shipbuilding also threatens the survival of the shipbuilding
industry in these modern societies.
For many middle size shipyards, the implementation of change from conventional to high-tech shipbuilding
technology is difficult and has to be done carefully. Internal resources at individual yards are very often not
available as regards to the wide range of knowledge required for the technological changes.
9.8.5
Laser technology – A revolution in shipbuilding
The need to retain market share in the world market of shipbuilding has forced many European yards to
make structural changes, with the objective of increasing productivity.
TheGermanmaritime sector, like Blohm&Voss GmbH shipyard inHamburg, has highly innovative production,
with a close interaction with other shipyards to maintain and improve competitiveness of its maritime
cluster. This yard manufactures high-tech ships as frigates, corvettes, fast cruise ships and mega-yachts.
Achieving a satisfactory increase in productivity based, among other things, on the ability to introduce and
apply new production technologies and improved measuring techniques. In this context, the concept of
precision manufacturing in steel shipbuilding has become important.
Precision manufacturing means production to very narrow tolerances, minimising assembly costs by
removing the need for straightening and adjustment. Precision manufacturing is particularly notable in
reducing rework and minimising throughput time at critical points, thus increasing productivity. Current
sectional shipbuilding methods involve the prefabrication of huge modules (volume components consisting
of walls, decks and bulkheads) in large shops. The following technologies and methods have been introduced
in the field of pre-fabrication:
Combining laser cutting and laser welding in one production line, along with complex clamping
technology that renders exact pre-positioning and tack-welding of components unnecessary.
Automating the precision manufacture of shipbuilding panels with considerably less thermal
distortion than when using conventional joining methods.
A new approach to designing steel ship internal structures from modular, standardised, precision
steel subassemblies, referred to as parts families.
Within the hull (shell plating) there are numerous decks, walls running fore and aft and transverse partitions,
such as bulkheads and transverse walls, all connected to form a supporting framework. This makes it possible
to use plate and sections of much reduced thickness compared with, for example, container ships. Reinforced
plates with a thickness of 4 mm are not uncommon. The numerous flat panels in the ships from the shipyard
can be particularly prone to distortion, due to the reduced thickness of the plate and the sections.
Laser technology with a much smaller HAZ, is setting new standards in shipbuilding production technology
in terms of minimal thermal stress. 240 km of laser welds for each ship gives an idea of the potential savings
that can be achieved by the introduction of this technology.
9.8.6
Aluminium ship fabrication
For fabrication of ship hull and superstructure in aluminium, labour hourly cost amounts to 60-65% of total
production cost for an average ship. The greater part of this cost consists of forming and assembly of plates
and profiles and welding. For ships built of steel the same cost is only 20-25% of total production cost.
A major reason for this difference is the much lower degree of mechanisation and automation within
welding in the aluminium industry. Here, the technology that can be offered has not yet reached the same
