Operating a ship at sea demands a huge logistic effort. Spare parts on board are important as machines can break down and equipment suffers from wear and tear. The question every logistic officer on board has to keep in mind is what kind of spare parts and how many of them do I need? Obviously some things break down faster than others and those demand a bigger supply of spare parts. Larger spare parts such as engine blocks for example are too big to be stored on board. Al these factors make logistics on board a difficult task.
When spare parts are not available a ship must set course to the nearest port. This has to be a port that is big enough to harbor the ship and for which the ship has diplomatic access to visit it. The ship can then await the arrival of the spare parts being sent over from home. This is a time consuming process and can leave a ship inoperational for several days, depending on how long the spare part takes to reach the ship and how long it takes to install them.
3D printing offers a new way in making logistics simpler. Being able to print the spare parts you need sounds like a big advantage. It would reduce the stock of spare parts on board and would abolish the need for having spare parts sent over when the ship is operating away from home
There are however some pitfalls. 3D printing does have the capability of making certain spare parts on board and reduce the need for a large stock of spare parts. Certain spare parts however are impossible to be 3D printed. Either these parts are too big for the printer or are used in machinery where they have to withstand high temperature and high pressure. 3D printing does sound nice for the smaller spare parts such as bolts, screws and other small things and can have certain applications but what about printing a piston for the engines, or turbine blades? Unless the polymer used for the printing is capable of the physical stress under which the printed spare part has to operate, 3D printing will have its limitations.
A second problem is space. Where will a 3D printer be placed on board of a ship. Take into account that a navy ship is built to be as economic with space as possible. There are no spare rooms that can be used to set up a 3D printer as every room on board is already used for a different purpose. And then of course there is the question of movement. How will a printed object look as a ship constantly pitches and rolls? Does the movement of the ship have an influence on the printing process and if so what is the tolerance? These are questions that can only be answered by putting a 3D printer on a ship and see for the result.
A third problem are spare parts for the printer itself. Using a 3D printer for making spare parts only works as long as the printer works. If the printer is broken you need spare parts to repair the printer. There is a risk that the reduction of spare parts by using 3D printing is needed to store the spare parts needed to repair a 3D printer when it is broken. Another problem associated with a 3D printer is the need for storing the polymers used for 3D printing. These polymers come in the form of a powder that needs to be stored on board of the ship. The amount of powder needed is equal in terms of volume to the spare parts it is intended to make. The only advantage is that the powder, either in bags or canisters, are easier to store. In fact, it can be stored more efficient then spare parts as the need for separating the different spare parts in their respective magazines on board can be replaced by the need of one big storage location just for the powder.
A last problem is the storage of the damaged parts. The advantage of executing large or complicated repairs in a port is that the damaged parts can be evacuated immediately and be send home. Repairing at sea means that the damaged parts have to be stored on board until they can be evacuated from the ship.
3D printing has certain advantages as they can reduce the stock of spare parts. However several questions need answering before 3D printers can be used on board of ships. One question is what kind of spare parts can a 3D printer make? Not only for the small things as bolts and screws but also pistons, turbine blades and anything sophisticated and capable of operating in an environment with high physical demands.
Another question is what the effect of a moving ship will be on the printing process and can spare parts be printed within an acceptable margin of tolerance? And third, how effective is 3D printing? Can the reduction in spare parts be big enough to have a major effect in logistical operations on board? Especially since one has to take in account that the spare parts of a 3D printer cannot be printed once it is broken. The storage of the polymers needed to print and what to do with the damaged parts while at sea are also questions that need answering.
In conclusion we can say that 3D printing offers advantages in terms of repairs while at sea but the technology will at the same time have such an impact that one needs to rethink the logistic system on board.