What is a retrofit?
At its simplest, a retrofit is the installation of new equipment or capacity to a vessel after it has entered service. However, the term is also used in a wider sense to include the complete conversion of a vessel to a new use and transformative procedures such as extensions. Generally, the motivation is to add new capabilities or extend the life of a vessel. Sometimes this will be a business decision made by the owner, or else in response to changes in regulations. Perhaps the most common incentive today for what can be major and expensive works is environmental. Not only are new regulations demanding reductions in carbon and NOx emissions, but the customers of ship owners are also requiring that their vessels be more eco-friendly in response to pressures from their end-consumers.
Environmental retrofit: reducing emissions
Retrofits that are driven by primarily regulatory moves to tackle climate change focus primarily on the need to reduce emissions resulting from using fossil fuels. This can be tackled at the source by changing a vessel’s engines so that they burn cleaner fuels, or by installing hybrid energy systems, both major undertakings. The alternative is to retain the existing engines and instead install ‘scrubbers’ that remove the gases and particulate matter from the engines’ exhausts. The choice tends to come down to which is the most economical at the time.
Ballast water treatment systems
Another major environmental issue, at least for long-distance vessels, is the issue of the transfer of invasive aquatic organisms in ballast water between differing marine ecosystems. New regulations require that this be managed using ballast water treatment systems (BWTS) that neutralize the micro-organisms as they enter or leave the ballast water tanks. The modular formats of some of these systems make the retrofit process simpler and less expensive than that for scrubbers, but it remains a major issue for many ship owners.
Extension, conversions & more
Other types of retrofit can transform a vessel, changing the way it looks as well as its purpose. The rationale being that it is quicker and cheaper than buying a new vessel. Lengthening a vessel, separating it into two sections, and inserting a new one in between, is an example of this and is most commonly applied to ferries and other passenger ships to add additional accommodation. Cruise ships generally require extensive works during their lifetimes to keep them up-to-date with their customers’ expectations. Most recently, an excess of platform supply vessels has led to them being purchased at low prices and being retrofitted for use in the aquaculture and wind farm support sectors. This is not only efficient recycling, it also serves the useful function of transferring excess capacity in one market to another that requires additional resources.
Laser scanning is an important tool in retrofitting. Its ability to rapidly build up precise 3D imagery in the form of Point Clouds has dramatically reduced the time required to take measurements within spaces inside a vessel, as well as increasing the accuracy to two millimeters or less. It can also be used on the outside of the vessel, for example, to check shell side quality or check each block section before they are weld together.
An added benefit is that it is simple to use. However, it takes the eye of an experienced engineer to identify the various locations within a space from which the scanning must take place in order to generate a comprehensive, detailed 3D image.