Continuing our series of posts on upcoming developments for version 10.2, let’s now look at a further relaxation of the rules relating to object connectivity.

In version 10.0 we made it possible to connect lines to lines and to form chains of connections, e.g. 6D buoy1 is connected to 6D buoy2, which in turn is connected to 6D buoy3 etc. In version 10.1 the constraint object was introduced, and mid-line connections were enabled.

In version 10.2 it will be possible to connect both vessels and 3D buoy objects as slaves of other objects.

The new functionality is implemented in the obvious way. For instance, for 3D buoys the relevant part of the data form used to look like this:

From version 10.2 the data form now looks like so:

The new Connect to object column specifies the master object. Here the buoy is Fixed but it could equally be free, or connected to a vessel, a 6D buoy, another 3D buoy, a line, a constraint etc. The vessel data form has been updated in the same fashion.

We don’t feel that the 3D buoy object is very widely used, or even especially useful, being so much less capable than the 6D buoy object. We decided to make the change to allow slave 3D buoys as much out of a desire for completeness as anything else.

On the other hand, the change to vessels is more significant. It’s certainly true that connecting a vessel as a slave of another object is a rather unusual thing to do, but there are applications where this is desirable.

The sort of example that motivated us to make this change are systems with two or more floating bodies which are coupled mechanically, for instance certain offloading systems. If the bodies are large enough to require the use of diffraction data then they need to be modelled with OrcaFlex vessel objects. The mechanical couplings would commonly be modelled using constraint objects, but this does require one or more of the vessel objects to be connected as slaves to other objects. The new functionality makes such analysis possible.

One final point to make is that slave vessels are not currently supported by the frequency domain solver. There are significant technical hurdles to overcome before we could support this feature in the frequency domain. If we see sufficient user feedback that the feature would be desirable and useful then we will look into adding frequency domain support in a future release.