A Class catamaran candidate hull shapes in one of the final evaluation runs. The chosen shape is now finalised. Detail design is next as virtual models are being prepared for machining…Read More

Some revealing images from the A Cat RANSE modelling: Small changes in pitch have very interesting effects on wavemaking and, therefore, on drag. Contrast the shape of the breaking bow wave in these two snapshots… Taking that step forward or aft along the gunnel as conditions change is really important.Read More

Well, the longer  than initially planned but more sophisticated hull CFD test schedule is nearing the end… Results have been very informative. Work will now shift to deck shape and crossbeams while preparations continue for construction. More will be unveiled soon.Read More

Previous posts on A Class Catamaran material choices hinted at the influences of core type on construction process. Let’s look at the options in construction method and the unique requirements of each. Foam Core Hull panel lamination can take place in one or two steps, depending on whether a perforated core is used.  A perforated...Read More

Picking up where the last A Cat post left off, we were contemplating the relative merits of foam core and Nomex style aramid paper honeycomb. Honeycomb is a very efficient structural solution because it concentrates material in effective load paths between the skins.  Each cell is braced at the interface with other cells, and there...Read More

As mentioned previously, the choice of tooling material and shape depends on the construction process of the parts to be moulded. To decide on construction method we look at the desired properties of the finished product.   The hull can be thought of as a box girder that has to resist global bending loads and...Read More

Graphic visualisation of hull wave height around a candidate shape. These simulations are very intensive in terms of processing power, so must be used selectively to keep time frames realistic. Fortunately we are in good hands. More will be revealed soon.Read More

Just a quick progress report for those of you who are regular followers. Design work is going well with some very interesting insights already in the bag. A promising hull concept has been identified and tests have started on a family of variants.The opportunity came up to run some more advanced simulations than we had...Read More

Having chosen a hull and foil geometry, the next task is to execute the carefully optimised shapes accurately and efficiently. Class rules mandate a minimum overall weight of 75Kg for the complete boat with no other restrictions on material and shape above the waterline.  Keeping weight at rule minimum is very important for performance as...Read More

Hopefully those of you who had the patience to follow this series of posts now have a clearer understanding of the state of play in A Cat design. This will be the last instalment on geometry and dynamics. I will cover structures and detailing in the next post.We saw that the boats are powered by...Read More