The boats currently involved in the Volvo Ocean Race are 65-foot “one-designs,” meaning they’re all built and equipped exactly the same (except for their crews, of course). This around-the-world race is probably the most grueling contest there is for both boats and people.
I had the rare opportunity to get on board the Team SCA boat during the race’s stopover in Newport, R.I. Even better, I got to have a chat with the techs in charge of in-port servicing. Most reporters want the inside story on tactics, crew diet, and how the team members deal mentally with weeks at sea working a 24/7 grind at top speed. Not me -- I know these crews are at the top of their game. I want to know how the electrical and mechanical systems installed on these boats are holding up after tens of thousands of ocean miles, and, if there have been problems, what they were.
As you might imagine, saving weight is key on these all carbon-fiber boats, and this opens the door to using the very latest in high-tech gear for onboard systems, an area where subtle changes in design can make huge differences in overall weight. Since all of the boats are equipped identically, my findings with the SCA boat will probably apply across the fleet.
One of the very first problems revealed to me was that the installers had learned a lot about how to locate equipment to minimize the risk of failure from seawater spray and splash. They admitted that some of the “watertight” areas of the boats where water-sensitive electronic gear had been installed had turned out to be not so watertight after all.
In the final analysis, the most common failure point on the gear was at the wire cabling termination points. I noticed in the electronics service container that more than a few NMEA cable ends were on the replacement parts lists for all of the boats. Keep in mind that these boats are almost exclusively wired as a network system, with a combination of C-Zone digital switching systems and Mastervolt MasterBus systems controlling all on-board DC equipment via several 7” B&G touch-screen displays (Fig. 1). Apparently there had been a bad run on the B&G displays, as there had been some display failures on deck due to water ingress. The techs implied that this had been resolved with the replacement units, with no further problems to report.
As a part of the weight-saving design concept these boats all employ 24-volt DC electrical systems. By doing this, significant weight savings can be achieved because wiring size can essentially be cut in half as compared to a more common 12-volt DC system. Fig. 2 shows a typical wire run through the boat.
Additionally, the use of two Mastervolt lithium-ion batteries (Fig. 3) saves as much as 70% in weight over more traditional battery technology. Further, these batteries get recharged via two extremely heavy-duty Mastervolt alternators (Fig.4) with 150-amp ratings each. These alternators are driven via a single Volvo-Penta diesel that serves as the combined generator/propulsion engine. With comparatively low-current-draw equipment, high alternator output, and a very high recharge acceptance rate for the lithium-ion batteries, the engine run time is minimized. It generally takes no more than one hour a day to bring all systems up to full charge. This of course minimizes diesel fuel usage, meaning less fuel – therefore less weight – needs to be stored to get through each leg of the race. So far these systems have performed flawlessly according to my SCA sources.
One interesting little problem that was discovered is something that anyone dealing with carbon fiber needs to be very aware of. These boats are relatively un-vented down below in the living spaces. This is all part and parcel of keeping the water on the outside and the inside relatively dry. So, electric fans are set throughout the living areas to get some air moving and keep things as livable as possible. At one point it was discovered that the circuitry for the fan motors was short-circuiting to the hull of the boat due to the backside of the fan motor coming in direct contact with the carbon hull.
Categorically, electrical equipment through-bolted or screwed into a carbon laminate should be double-insulated so that no electrical charge can enter the hull laminate. This was a lesson learned the hard way for the Volvo Ocean Race gang, but fortunately nothing catastrophic happened in this case.
Fig. 5 shows the bulkhead located just to starboard of the navigation station on board Team SCA. The carbon bulkhead is loaded with electrical/electronic gear. Is it all double-insulated? I didn’t check, but really do wonder what the status is with all that gear.
Finally, the only other piece of equipment that acted up during the leg into Newport was a pipe fitting that connected the Spectra watermaker (Fig. 6) to the onboard tankage. A crack developed in the fitting, causing a leak in the system that creates the all-precious fresh water. The watermakers, I’m told, are performing flawlessly, but this little glitch apparently caused a bit of panic. No problem a dab of epoxy couldn’t handle, though. The repaired fitting made it to Newport without issue and a new one has been installed.
So, what’s my take-away from this? I’m thrilled to see that under the toughest conditions we can dish out, new-tech electrical systems are proving their mettle. All we humans need to do is continue to understand that electricity and water need to be separated. These Volvo crews are learning now how to do just that.
This is where trickle-down technology really happens. Real world, real boats, really good gear.
For an interview with two members of the Team SCA crew, read Olympian to Ocean Racer: Making the Sailing Leap.