“We've been on a fantastic journey together where we've learnt a lot for the future,” reveals Jonas Welinder, Product Planning. When Volvo Penta presented its new unique protection system for sterndrivers – Active Corrosion Protection (ACP) – in a press release, it marked the end of a long and intensive piece of work.
For more than three years, Henrik von Porat, designer, Katarina Hammar, technical project manager, Jonas Welinder, product planner, Alexander Johansson, project manager, Johan Källvik, product developer electronics, and corrosion specialist Viktor Räftegård developed the system together.
The work was performed in batches, and all six engineers had other projects on at the same time. But the support from Volvo Penta was always there. “This is a priority area for Volvo Penta. It’s about ‘easy boating’ and is strategically important in order to be able to protect customer relations and facilitate boating in the leisure segment.
As a result, we also knew that we had full support to do this as well as possible,” Jonas Welinder says.
Up to now, corrosion protection on Volvo Penta's sterndrivers has consisted of what is known as a sacrificial anode, a block of metal, such as zinc or aluminium, which is attached to the drive.
The idea is that the anode intercepts corrosive attacks before they get to the drive. Its success depends on the metal in the drive being more noble than that on the anode. “It’s a proven method of passive protection that has been used for a very long time,” says Viktor Räftegård.
However, the problem with this method is that the anode has to be replaced on a regular basis, sometimes several times a season, depending on the environment and how the drive is used. The onus is thus on a boat’s owner to keep an eye on the anode to make sure it has not worn away and that corrosion has not started to affect the drive.
The ACP system, on the other hand, is an active form of protection. This means that the system takes care of itself and actively works to protect the drive from attack. The ACP unit is mounted on the transom of the boat.
By constantly measuring the drive's potential, the unit adjusts the current from the anode, which in turn can maintain a constant level of protection and prevent corrosion from attacking the drive.
“This provides superior safety and protection. The boat owner can relax, safe in the knowledge that constantly updated values are provided at the helm,” explains Viktor Räftegård.
Volvo Penta is the first
This type of protection is already on the market, but for larger boats and other units, such as Volvo Penta’s IPS system. The difference now is that the six engineers have adapted this to the inboard motor and leisure boats. This makes Volvo Penta the first boat engine supplier to offer this.
The group talk of many years of tests and measurements and how they often had to use their creativity to solve problems. One example is the self-designed 3D models that made it possible to quickly see test results and designs.
Another is the idea of using a thin band of MMO-coated titanium and placing it around the ACP unit instead of mounting rods on the unit, a design whose effects included reducing the weight of the unit.
“It goes without saying it’s been a journey of peaks and troughs of emotions and commitment. It has been a major technical challenge, but we never doubted it would work out.
This is a great group of people who complement one another, and we've had a fantastic time together. I’m proud of what we've accomplished,” Jonas Welinder says. Viktor Räftegård agrees.
“We've developed a high-quality system for our customers. What’s more, we've learned a lot along the way that we can now put to use in new projects going forward,” he concludes.
What is corrosion?
The word corrosion comes from the Latin corrodere, which means ‘gnaw apart’. It means a process where a material, normally a metal, is dissolved via a chemical, often electrochemical, reaction into a more stable form, such as an oxide, hydroxide or sulphide. Rust is a specific form of corrosion that applies only to materials made of iron and steel.
Read more about the technology behind the ACP system on Volvo Penta’s website.
Interested to join our teams? Visit our Career page.