engine

Engine technology to watch for

With the recent release of the final report of Nigel Calder's HyMAR project, marine internal combustion / electric hybrid powertrains are making waves once again- and not necessarily in a good way, as Calder's team found that the benefits of the expensive hybrids were limited to a relatively narrow, low-speed operating regime. We've known for quite a while that the major advantages of gas/electric and diesel/electric hybrid cars- namely, instant start/stop and regenerative braking- don't apply to boats. We've also known for quite a while that hybrid systems only make economic sense aboard ship if the house loads are comparable to, or larger than, the power required for main propulsion.

Tech addicts need not fear, though: There are many other fuel-saving and pollution-reducing technologies waiting in the wings, and hybrids aren't quite out of the running yet.

Steering and throttle cable routing

Control cable routing is often a bit of an afterthought. In a small, simple boat, it's often OK for the designer to more or less ignore the engine controls, and trust that the builder will know how to install them. That approach doesn't work so well for a larger vessel, like the Starwind 860 trimaran, in which the exact routing of each control cable must be planned out to avoid conflicts.

Outboard motorboat power calculations

Every year, mixed in with the usual chatter around the boatyards, I hear at least a few comments along the lines of "I beefed up the transom of my 14-footer so it can take 60 horsepower!"

Er, no. That's not how it works.

Maximum power ratings for small outboard vessels are calculated according to the size and design of the boat, taking into account the following factors:

  • Length of hull (longer = higher power rating)
  • Beam at transom (wider = higher rating)

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