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John Miele

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Top Stories by John Miele

A posting related to the belated holiday season’s greetings here. Something to ponder for the New Year: Block Coefficient:  The ratio of the volume of water displaced by a ship to the product of the  ship’s length, breadth, and draft. A couple of weeks ago, I was in our Cannes headquarters meeting with our president, Mr. Paul Bezzi. We were looking at some quotations, and Paul said to me, “John, I’ll bet you don’t know this, but I can tell you exactly how much Jesus weighed.” “Huh?”, I replied. It is simple. You know, in the Bible it is mentioned how Jesus walked on the water. Well, the water density of seawater is well-defined: A known variable. But remember, Jesus was walking around on the Dead Sea, which is a much higher density. In order for Jesus to walk on water, his displacement must be higher than the density of the seawater. So, if I know the size of Jesus... (more)

What is the difference between cavitation and electrolysis?

The following paper was presented by France Helices’ president a while back. It discusses the difference between cavitation and electrolysis and the impact of both on propellers and propulsion. These two phenomena are often confused and it is important to learn to recognize the difference between them, so that the cause of problems can be determined and adequate fixes can be made. We have translated this version from the original French version. We hope you find it interesting. Introduction I have often had the opportunity to see during my career that there was some blurring in... (more)

Auto trim

  When France Helices installs an SDS on a vessel, we always include operator training as paart of the package. Operating a vessel at 30 knots is a very different skillset than operating a vessel at over 50 knots. Why? Well, there are many reasons, but one of the things that often confuses crews new to the SDS is the concept of drive trim. The trim of the drives is critical when operating the SDS. Remember in an earlier article that we stated that one of the functions of surface drives is to provide lift. The SDS literally lifts the stern of the vessel out of the water, thus al... (more)

Welcome to Tier II NOX Regulations

On January 1, the MARPOL Tier II NOX regulations went into effect. From this date onward,  marine diesel engines may emit no more than  7.7~14.4.0 g/kWh of NOX, depending on rating. Tier III goes into effect on January 1, 2016, five years from now, with NOX limits of  g2.0~3.4 /kWh. Though Tier II requirements have been known for a while, very little was written about the implementation date of the regulations. Some vessels are “grandfathered” into the regulations, whereas most other must comply. Some ship owners are letting the engine maker deal with the problem, taking the op... (more)

Two New Patrol Boat Designs from France Helices

We have just made the following designs available for sale: A 22m Patrol Boat and a 28m Patrol Boat. Take a look below and feel free to contact us with any interest. 22m Patrol Boat                                           28m Patrol Boat   Share! (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })(); Tweet Follow ... (more)