The Naval Architect: February 2020
Although the concept has loosely existed since the 1970’s, Building Information Modelling (BIM) didn’t truly go mainstream until the turn of the century. Within a few years, BIM had become so integral to construction projects that it was mandatory when bidding for government contracts for most countries in Scandinavia and central Europe.
Despite the obvious parallels, ship construction has largely shied away from such an approach. But late last year, Norwegian architectural firm YSA Design announced it was close to completing what it says is the first cruise ship construction project to bring together everything from initial sketches to the sign-off tasks for utilities completion under the BIM process.
The owner of the undisclosed vessel was keen to explore the accuracy and efficiency benefits of using uniform 3D modelling for all stakeholders in every stage of the project. Although YSA Design is most closely associated with cruise ship interiors in the maritime sector, its experience with land-based BIM projects made it an ideal choice not only to produce 3D drawings of the whole ship (using the Autodesk Revit modelling software), but also to oversee the entire process on behalf of the client as the BIM Coordinator.
“We were recommended to draw the whole ship in 3D, from top to bottom,” explains Georg Piantino, senior architect, YSA Design. “But with BIM, when a contract is signed, and an agreement to work in 3D, then you must also assign one person or group to act as the BIM Coordinator. That [Coordinator] could be the client itself, or the shipyard, depending on how technically minded they are.”
Establishing BIM rules
The BIM Coordinator’s responsibility is to take all the different suppliers’ models and create a BIM Manual, which is sent out before the project starts. This establishes the routine of the model sharing process.
Although many outfitters, plumbers and electricians are already drawing in 3D, many still don’t feel comfortable about sharing plans in this way. “We sometimes get 2D drawings that have been laid out in 3D but then exported and shared so that it looks like a 2D printout,” says Piantino.
“Traditionally, when you get the steel drawing you would then sketch the outfitter drawing above or beneath it to figure out if there is any collision, then physically make a red line comment on the drawing and send it back to the shipyard,” he adds.
3D modelling makes the process far quicker and more accurate by allowing the user to run a clash report which highlights areas where there is a collision. These collisions are highlighted in red, yellow, or green based on their severity.
Because the BIM is intended as a lightweight model (i.e. not data heavy) it is easy for different users to make their own sections and elevations, zooming inside the model to check the positions of features such as ventilation. This helps very much in understanding the design intention.
For shipowners, who often have little understanding or time to spend reviewing traditional drawings, working with BIM holds the additional advantage that it can be complemented with virtual reality (VR) software that makes it possible to experience the space in a more digestible form. Piantino says the application of VR is an aspect of the BIM process he’s particularly passionate about.
“With the VR glasses on you can go through the project and really see one-to-one how the room feels and where the problems may be. Then using the pointer you can click on an area to find out what material is being used. The display will bring up a little note saying, for example, that you’re ‘standing’ on a marble floor of 25m2 and 60mm thick.”
As the project is ongoing, it’s still difficult to arrive at a clear idea of the time and cost benefits of the BIM process to the entire project. However, Piantino thinks the most significant differences were felt during the earlier stages, given that the finished product had been created in its virtual 3D form before steel cutting had even commenced. Moreover, the experience of managing an entire shipbuilding project in 3D promises to open up new business opportunities for YSA.