Quote:
| Originally Posted by catmando This is a very nice boat, but why would they mount the engines so far forward?? I would mount them rearward using waterjet drives for shallow draft. |
Good observation Catman! And an interesting question. There are a couple of reasons why the engines are (and appear) to be mounted further forward than one might expect...
A primary reason is Center of Gravity, but secondary... if you study the artist rendering below, you will see the hull tapers to the exit of the shafts. The props are placed immediately behind this point. The space leading up the buttocks of each sponson becomes progressively more narrow, thus reducing interior engine room width/space. The recessed, flat under-side of the aft deck/swim platform extends beyond this point and serves two purposes... additional lateral stability and a partial planing surface.
What is NOT shown in the original construction picture is the bulbous bow extensions that were added to each sponson. I've attached another picture showing their later incorporation. The bulbs were added after the initial sea-trials, when it was determined they would help the cat run flatter and reduce pitching in various water conditions.
The bow picture below also reflects the relatively narrow cross-section of the sponsons, which is one of the reasons the sponsons have an extended flat running surface under the swim platform. (increased stability)
Pacific Harmony is not typical cat hull configuration. It is actually a displacement hull with wave-peircing attributes. Here is a link that better defines the concept...
http://www.winteryachts.com/catamara...ny_design.html
Waterjets could be an option and the narrow cross-section of each sponson would lend itself to a high level of maneuverability, as there is no resistence to backwash.