S/V Barbara Ann

Performance Evolution (cont.)

S/V Barbara Ann completes her tranformation with conversion to regenerative hybrid electric propulsion

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I’ve always preferred un-stayed rigs since experiencing the joy of International Finn sailing.  The bendy mast provides extraordinary sail control and automatic adaptation to big puffs. The lack of stays makes the uncontrolled jibe a gentle norm rather than a traumatic event.  The new sail plan has all the right stuff to make a 57’ boat handle like a 15’ dinghy.

The Barbara Ann was always packed with its systems, and in 2008 some were starting to fail.  The Glacier Bay refrigeration and air conditioning systems were no longer manufactured and were much larger, noisier, and heavier than more modern units.  Holding tanks and hoses needed replacing.  The controller for hydraulics was obsolete, no longer manufactured and dead.  The engine had always lacked precise control that could have been so valuable for single-handed docking and maneuvering.

In summer of 2009, I determined that enough systems were obsolete or failing that it was time to re-think how things were put together inside the boat.  I had a few additional design problems that I hoped to resolve by a systems refit:  Because the new rig was 600 lbs lighter than the original S&S design goal, we had a slight trim problem; the Barbara Ann sat a bit heavy in the stern.  I guess that’s not an unusual problem in middle age, even for a boat.  I wanted to move the CG forward with the systems, since it was not practical to move the sail plan forward.


Also, the heating system stank, literally.  The smell of diesel would permeate the boat in winter and the heater would invariably fail in February, and need to be dismantled to clean the nozzles.  It was time for clean, safe, dependable electric heat.

I started investigating hybrid electric power solutions.   The diesel heater and generator were both far aft in the boat, and the 100HP Yanmar open frame engine sat aft of mid-ship.  If I could power electrically, I could use a light weight electric motor and put a single generator anywhere that would balance the boat. 

I started contacting companies offering solutions and found that few actually existed and the most promoted and heavily advertised of the companies were total fakes.  Since I had already started tearing the boat apart, I decided to roll my own hybrid propulsion system and hired the best high voltage engineer I could find.  Although there are a number of sailboats that have been converted to hybrid or electric power, they are either large military ships, or small boats needing less than 20HP to power them.  It had been determined when we built the Barbara Ann that we need around 70 shaft horsepower to reach hull speed.  Even more important, we needed that power for times when we got in trouble and needed some power to get us out.

Barbara Ann is much larger than the typical hybrid sailboat.  With the extra power needed comes numerous engineering challenges.  To keep within a manageable current, we had to go to a high (read dangerous) DC voltage.  At 350VDC, arcs can happen that weld breakers shut, start fires, burn off limbs, and generally raise havoc.  Above 450VDC, the cost of breakers and switches is more than the typical diesel engine.  We determined that the “sweet spot” for us was 326VDC and a maximum current of around 200A.

We also decided to come up with a true hybrid solution, rather than diesel electric propulsion.  If you can use the prop to regenerate power while under sail, a sailboat is a nearly perfect hybrid vehicle.  Unlike a hybrid car, which only regenerates power while reclaiming some of the momentum lost through braking, a sailboat in medium to high wind has excess power on its sails that can be used to charge the batteries for house needs and for maneuvering power later. 

Using the boat as a windmill for power generation means that you need a place to store the power for later needs.  The boat would need a huge battery bank.  In the earliest hybrid marine boats, World War II submarines, the battery banks weighed over 200 tons and the circuit breakers were as big as phone booths.  In the Barbara Ann, we use 26 thin plate lead sealed lead acid batteries totaling a little over a ton in weight. 

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Bill & Barbara Southworth
39 Pickering Street  • Portsmouth NH 03801 USA
Cell: (617) 905-6800 or (617) 905-6803 Fax:(888) 300-8888