Smooth sailing with Volvo Penta6/25/15
Over the years, demand has grown for a Saildrive capable of powering larger boats; originally designed for 8 to 10 meter yachts, Volvo Penta’s standard Saildrive is now included as part of the Volvo Ocean 65 Class — a boat designed, engineered and built to be a high performing, competitive race machine.
With boats in the marine leisure industry increasing in size and power year on year, Volvo Penta’s standard Saildrive has had to keep up with ever-growing market demand. It’s evolved over the decades to become capable of inclusion in longer and more powerful boats, although at its core nothing has drastically changed.
“The Volvo Ocean Race’s custom-built racing yacht has a hull length of 20.37 meters [66 feet]. The appearance of a completely standard Saildrive in the Volvo Ocean 65 Class, which is exactly the same as every other Saildrive produced, is testament to its ability to perform consistently in boats of many different sizes and power ranges,” says Lars Ljungqvist, senior vice president of business development at Volvo Penta.
“Racing in extreme weather and sea conditions is incredibly tough — not only for the teams but for the equipment too. Every part and component packed into the Volvo Ocean 65 Class has to perform at the top of its game and this year the Saildrive didn’t disappoint.”
The difference is in the details
The difference between today’s Saildrive and the one first released in 1973 is in the details. Some of the upgrades, which have been added over recent years to produce a smoother, more comfortable boating experience, include:
- Saildrive oil can be changed from inside the boat;
- Crash absorbers keep the engine in place in the event of impact;
- Electrical isolation of drive and propeller minimizes the risk of corrosion;
- Three-point suspended mounting minimizes noise and vibrations with no need for alignment;
- Hydrodynamically optimized design lowers drag while sailing.
One of the most important innovations since the Saildrive’s launch has been the introduction of folding propellers. Volvo Penta’s unique, streamlined folding propellers reduce the boat’s resistance in the water, maximizing thrust while motoring. With 2-, 3- and 4-blade versions for engine outputs from five to 120 hp available, there is a solution to meet most sailors’ needs.
“Maintaining Volvo Penta’s original vision for a quiet, vibration-free system, the folding propellers have proved themselves an excellent addition to the Saildrive concept,” explains Lars. “Although little has changed since 1973, the folding propellers — as well as other additions — ensure the Saildrive continues to improve.”
Endurance racing with Volvo Penta
This year, the Volvo Ocean Race took to the high seas once again, and at the heart of each competing yacht was a Volvo Penta D2-75 with Saildrive. The 75 horsepower engines meets many demands onboard the race boats — providing electricity that powers the communication equipment, heating and water purification system; keel movement, adding extra counterweight when sailing; and propulsion, used in emergency situations or for motoring in and out of harbors.
By generating each boat’s total demand for auxiliary and propulsion power, the Volvo Penta D2-75 with S-drive is essential in helping the teams compete in and complete the race successfully.
Early in the race, on the second leg between Cape Town, South Africa, and Abu Dhabi, UAE, Team Vestas Wind was grounded on the Cargados Carajos Shoals in the Indian Ocean. During the accident, the crash absorbers proved their worth, holding the engine in position on impact.
In addition, the Saildrive’s hydrodynamically optimized design also gives low drag and minimal resistance in the water, making it the ideal sailing component for the teams competing in the Volvo Ocean Race.
One of a kind
“When we designed the Saildrive all those years ago, we knew we were on to something special,” says Staffan Månsson, a retired Volvo Penta design engineer, who worked at the company from 1961 to 2006. “We wanted to fix the noise and vibrations, as well as shake up the engine’s traditional place in the boat. Out of this vision, the Saildrive was born.”
Before the introduction of the Saildrive, sailboat engines were located either toward the back of the boat, creating a steep angle on the propeller shaft, or toward the front of the boat, reducing the onboard living space. In addition, noise and vibrations caused by the engine were disturbing for passengers.
To counteract this, the Saildrive was originally designed by passing the propeller through a rubber skirt in the hull, while the engine and drive were combined to create one singular unit. The unit was then placed on rubber mounts, which helped maintain comfortable noise and vibration levels.
“The flexible rubber membrane that protects the drive and engine unit was initially treated with skepticism by the boating world,” Staffan notes. “Because of the softer material, people were worried that it wouldn’t be as durable or reliable — but this isn’t the case.
“Although the Saildrive can now be fitted in larger boats than ever before, there is no real limit on how long this trend can continue,” explains Lars. “Who knows what the future has in store for the Saildrive. It’s lasted 43 years, and of course there will be small developments and changes along the way that help to make a concept run more effectively or efficiently, but in the main I believe the Saildrive is here to stay.”