With all due respect it seems to me that there are at least 3 ways of dealing with the multiple engine single shaft idea. 1. Side by side main engines belted to a central shaft ala romsdal/malahide. I would use cog belts instead of v belts and the hardware is readily available. This can be sized to any horsepower rating that is likely to be applicable. 2. There are still a lot of WWII surplus detroit diesel based multiple engine to one shaft units out there. They use standard size bell housing circles. Adaption of modern engines to these rather oversized and robust units is not rocket science. There are still machinists that know how to do this stuff. 3 Hydraulically. With an engineered solution using higer pressures and large plumbing (for low oil flow speed) you can practically have almost any number of engines driving the shaft. I participated in a retrofit hydraulic drive to a cal 46 for a very knowledgable owner who claimed a substantial reduction in coupled noise and a noticable increase in fuel economy. Of all these the cog belt drive is the simplest, cheapest and easiest to maintain.... Set up to vendor specifications the efficiency, and therefore the effect on fuel burn, is computable. Jim Slocomb M/V Sea Otter 40' Skookum San juan Islands --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.830 / Virus Database: 565 - Release Date: 1/6/2005

At 08:57 AM 1/15/05 -0800, you wrote: >3 Hydraulically. With an engineered solution using higer pressures and >large plumbing (for low oil flow speed) you can practically have almost >any number of engines driving the shaft. I participated in a retrofit >hydraulic drive to a cal 46 for a very knowledgable owner who claimed a >substantial reduction in coupled noise and a noticable increase in fuel >economy. I have run 8000 miles with a similar system. It was not very satisfactory. Mike Capt. Mike Maurice Tualatin(Portland), Oregon