Superyacht stabilisers

A controlling influence

It’s not a coincidence that the word nausea comes from naus, the Greek word for ship. Owner and guest comfort onboard the yacht is paramount and the next generation of stabilisation systems are delivering incredible solutions.

A year ago, when Onboard last reported on stabilisation systems, much of the talk was about new electric fin stabilisers gradually being introduced by manufacturers, claiming a number of ‘unique’ firsts.

Claims such as being smaller, quieter, and easier to install, with quicker responding actuators made for an interesting debate.

Now, with fins and compact gyros being produced with the ‘mass-market’ in mind, today’s expectations have reached a point where it is genuinely unusual if a new motor yacht of even just 10m or above, does not have a stabilisation system ‘as standard’ or mentioned somewhere on the optional extras list.

Within this year’s report, it’s sophisticated control systems and associated software that stabiliser manufacturers have been focussing on in particular.

By utilising onboard wi-fi, engineers can connect, remotely, to service and maintain their systems, upload previous data, spot trends and diagnose faults before they even occur.

Quantum’s 5000S Control System, for example, is designed for remote access and is built on a modular platform, capable of supporting the old, current, and future control generations with greater capacity.  The new control has recording capabilities that can be stored and downloaded later even when bandwidth is limited, often the case with yachts mid-ocean. 

As far as what’s new and upcoming in stabiliser tech, over the last year, Quantum has been actively engaged in development of two exciting innovations.

Firstly, their Dynamic Load Control (DLC) which reduces the cyclic loading and the amount of accumulator storage required in a typical hydraulic power system. It balances the load between multiple pumps within the same hydraulic system and effectively stabilizes and limits horsepower fluctuations on the electric motor. DLC has been successfully added to three vessels to date, with a patent soon to finalise.  

Launching in 2023 is Quantum’s F45 Hybrid – hydraulic/electric power unit, with a prototype under development and patent pending.

The F45 system uses the best attributes of a traditional hydraulic system, and a direct electric drive. Katie adds: “The system is extremely efficient, has low airborne and structure born noise, minimal heat generation and low maintenance requirements. In recent testing, it is shown to offer smooth power that does not fluctuate and requires 50% less power than a traditional hydraulic system. The F45 meets both the long-term energy efficiency requirements and the peak transient energy needs of the closed marine electrical system.” 

While they might all look similar from the outside, with their mysterious looking glass spheres tucked neatly and securely inside a rigid steel frame, not all gyros are the same.

Pieter Feenstra, Smartgyro’s Northern European Sales Director, pointed out a number of subtle differences when comparing his products, over and above others on the market, and Pieter told me: “The base frame, for example, consists of four main sections which can be taken apart and handed-in through narrow hatches and reconstructed in tight spaces, making a retro-fit or new-build possible even in the tiniest of areas.

“The residual gas within the Smartgyro sphere is air, which can be refilled automatically by the built-in pressure pump, while the residual gas within some other gyros uses helium that require special tools to fill it.

“The built-in pressure pump that we use in a Smartgyro will automatically restore the vacuum after detecting a possible leakage, or after performing maintenance on the sphere.
“Similarly, management of the vacuum inside the sphere itself is another point of difference between us and others on the market. Air friction at 10,000 rpm is very high, and some use a high degree of vacuum to compensate for a less powerful, or less efficient electric motors. Unlike our motors which are directly liquid cooled, others are not and heat can sometimes get introduced into the sphere.

“The design of Smartgyro is different, and inside the ball everything is cooled with glycol, including the motor and bearing pack, so it is not necessary to use helium or other gases. Furthermore, repairs to leaks on spheres with anything other than air inside the vacuum are often complicated, and not possible to be carried out onboard. Over time, therefore, the vacuum itself gets depleted and the gyro gradually becomes less and less effective.”

Certainly, by looking at their VG range, for yachts from 65ft (20m) upwards, I would have to agree with Dan that each model looks nothing less than ‘bomb-proof’ in appearance, with everything encapsulated in a high-tensile steel square casing, with equally sturdy legs for secure mounting.

“Depending upon access, VEEM gyros can be installed without drydocking, which allows for simplified service & maintenance because all of our units are fully maintainable in the vessel without it leaving the water.”

When possible, operator experience and feedback and data collected from units being used regularly is vital to improve and enhance the overall experience. For example, VEEM has recently examined the condition of bearings and other wearable components in its longest serving machines, and this valuable intelligence has resulted in new operating guidelines and preventative maintenance intervals, that will extend the time between component replacement and reduce the overall cost of ownership.

It’s perhaps an obvious thing to say, but working with designers and yards as early as possible, to preserve adequate installation and service access, pays off in the long run.
VEEM, for example, recently supplied a pair of VG52SD gyrostabilizers for placement in the lazarette beneath a new fishing cockpit extension of a 42m tri-deck motor yacht in the USA. The VEEM in-country Senior Service Technician was sent in for a pre-commissioning inspection to assess location and assist the yard team with final configuration, so that both gyrostabilizers remained easily accessible for commissioning and future maintenance. 

Sitting down with shipyard OEM’s and trying to ‘second-guess’ the market over the next 3-5 years, is a preoccupation for Sleipner’s CCO, Marius Torjusen, and his design team.

They’ve not done a bad job, recently, with no less than three, forward-looking developments to tempt customers, including their new eVision thruster series, the noise cancelling feature on their new electric stabilisation system and 3rd generation vector fins.

 “When we launch something new,” says Marius, “it’s usually in response to a demand in the market and OEM partners are often keen to introduce novelties in their boats, to help them gain a competitive edge.”

As far as making an impact is concerned, Marius believes their latest generation fins will be the most warmly received.

Having hit the market running with their elegantly curved ‘vector’ fins that swooped the main prize at the DAME Awards back in 2013, the design has since received countless hours of tank-test simulation and ‘real-life’ feedback from owners and professional crew, as well as hours and hours of operation on their own test vessels at sea.

Looking like an eagle’s wing in mid-flight, the latest version has an even more pronounced upward rake than before and Sleipner claim the latest profile will offer up to 50% more stabilising force, compared to a flat fin.

Marius told me: “The new design helps nullify some of the side-effects associated with the paddling motion of flat fins, such as yaw, sway and ‘anchor walk’, and as the fins also create a significant lift force, much of the added drag is also nullified, making these fins very interesting for builders looking for more sustainable stabilizing solutions.”

Martin Bizzell, Engineering Director, gave me an unbiased view when he told me: “ABT-TRAC are the one of the original manufactures and developers of active fin stabilisation for yachts and traditionally use hydraulic systems.

“These are heavy-duty systems with load-bearing components that are intentionally over-sized, to cope with all sea-state conditions and give long service life. Double sealed shaft housings, for example, require no maintenance between haulouts.

“These can be maintained by a good hydraulics engineer, with the central hydraulic system able to drive thrusters, windlass & capstans, deck cranes, and any other hydraulic power equipment on board.

“Stepping things back a notch or two, ABT-TRAC AC electric system is quieter in operation and requires less maintenance than a hydraulic system but is limited in vessel size it can be used on.

“Swedish built Humphree DC electric fins system, on the other hand, is very quiet, easier to install, but requires larger battery banks and is limited in vessel size that it can be used on.
“Useful features, such as 360-degree rotation, combats ‘anchor-walk’, but having full rotation means you can set the fins to gently pull at the anchor, which keeps the nose pointing to the wind and stops the wind rocking the boat from side to side.”

Modern yacht owners are more informed about the market than ever, and now they have their eyes on the cutting edge of technology for new solutions with the potential to improve the experience. Above all, the priority is maximising owner and charter guest comfort.