Advanced shipbuilding – a change of risk from oak hulls to 3D printing

Shipbuilding was once the art of transforming hundreds of hectares of oak forests into hulls. Master carpentry moved to iron and then steel hulls, and now we are on the cusp of the next shipbuilding revolution, where autonomous, 3D-printed, graphene-made, LNG-powered vessels will be built by specialised suppliers with white-coats and augmented reality smart-glasses.

Leading the way

Japan, South Korea and China are currently the leading shipbuilding nations with large shipyards such as Imabari, Mitsubishi, Hyundai, Daewoo, Samsung, STX and China Shipbuilding Group. Although steel prices in Europe are higher than in Asia, Europe is also active in a few specialised market segments such as military, cruise, dredging, offshore vessels and luxury yachts.

Spanish shipyards can be characterised as one of these niche players. Geographically clustered in the northern coast of the Iberian peninsula, they share a high degree of specialisation and high-tech qualities, in combination with limited numbers of built vessels. Within the EU, R&D expenditures of Norway and Spain are highest.

The role of innovation

In this highly competitive, cyclical and capital intensive industry, specialisation and innovation are vital. All shipyards are constantly searching for cost-effective technology. With technological advance, the role of the marine equipment industry – as the supply industry to the shipyards - has increased dramatically. Previously, the bulk of the work – and the costs – related to the vessel’s hull. Nowadays, the marine equipment itself can be between 50%-70% of the vessel’s overall value (or even more for future autonomous vessels).

These are some of the innovations which may impact the shipbuilding industry in the coming decades:

3D printing

Subtractive manufacturing is an umbrella term for various material removal processes that start with solid large blocks that are shaped by removing material (in the same fashion that Michelangelo chipped away at the Carrara marble block to free the figures that he imagined inside of it). In contrast, additive manufacturing or 3D printing processes build real objects from virtual 3D objects by cutting and printing 2D slices, adding material one layer at a time, until it is complete.

Currently, this technology is being used by some shipbuilders for rapid prototyping or to showcase their projects by printing miniaturized physical ship models, but the prospect of using 3D printers to build specialized tools on board, or to seek quick replacement of ship’s parts, or for building major blocks with composites such as graphene is being investigated. While we may not see an entire ship 3D printed, substantial parts will be manufactured this way.

As-built 3D models - virtual and augmented reality

Currently, the shipyard’s production floor visualize the ship from 2D paper drawings and computer images and translate the information into a mental 3D view of the ship. But it is inevitable that a digital representation of the ship (a “digital twin”), together with virtual and augmented reality, will be used on every production floor in the coming decades. Designers, Engineers and Customers will be able to interact with the design in a Cave Automated Virtual Environment (CAVE).

The benefits of generating as-built 3D models will exceed the initial costs involved. The 3D navigation and even the interacting with the model in an immersive experience, allows the quick evaluation of modifications and design changes, the production checking and approval, simulation of maintenance, disassembly and operation tasks, training of crews and serves for commercial and marketing purposes.

Advanced materials

Today, steel is the king of shipbuilding bulk materials and no doubt that it will continue to be dominant for many years to come. But if the strict fire-protection requirements allow, tomorrow the throne may be conquered by graphene - carbon nano-tubes harder than diamond, less corrosive, lighter and stronger than stainless steel.

This (and other nano-composite materials) can also serve as coating, anti-fouling or welding strengthening material. Vessels built from this lighter material would require less fuel, hence increasing energy efficiency.

Robotics/drones

Future shipyards will be hybrid cyber-physical systems with humans and robots working together. Currently, shipyards receive information directly from a 3D model to cut a raw plate stock or a profile. In the future, there shall be no need to have a human translating a drawing into the machine.

In addition, drones may be used to transport materials from one location to another at the yard or to conduct verification and checks (via sensors), as some classification societies are already doing.

Propulsion and powering

Requirements for the reduction of greenhouse gases and exhaust emissions are already influencing propulsion, and powering technology development and the search for alternative fuels, renewable sources of energy, hybrid power generation, and emissions abatement technology.

Integrated electric propulsion technology (using electric instead of mechanical transmission, thus eliminating the need for clutches and gearboxes), together with Liquefied Natural Gas (LNG) are already starting to be used.

No doubt that the shift from diesel engines to low emission LNG engines will force many shipyards to adjust their production lines accordingly.

Comment

Although the idea of building (or printing) a large vessel on the nano-scale may seem counter-intuitive, regulators and classification societies will have to develop requirements in surveying and testing for these revolutionary nanomaterials.

Due to their strength and durability, these nano-composites are expected to reduce the navigational risks and enhance the working life of the vessels, but a watchful eye should be kept in connection with their potential noxious effects on humans, cargoes and marine ecosystems.

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