On board stabilisers is a hot topic at the moment inasmuch as owners are seeking ever more comfort on board at all times, when lying to an anchor and/or while cruising. New technologies aim to eliminate all that could disturb guests during prolonged periods on board like unpleasant pitch and roll. We met Marco Donà Saim’s DG. This firm distributes, repairs and offers specialised assistance to engines and highly technological components like stabilisers and told us how Saim got involved 18 years ago and of the four brands it is working with today – ABT TRAC, Side Power Vector Fin, Veem and Zipwake – each of these produce their diverse systems with varying features and specs. Let’s see what they are and how they work.
As for Saim’s involvement with stabiliser systems there’s a lot to say for them when in 2000 they kicked off with distributing American Bow Thruster, now ABT TRAC: “Initially since inception ABT were producing bow and stern thruster systems for large vessels – says Marco Donà (Saim’s DG) – At that time we were already distributing Max Power for smaller electric propellers and were scouting the US market for an appropriate device destined to larger yachts. No sooner we began to be distributors, ABT’S owner drew up an algorithm for stabiliser fins underway with a technology which was little known in yachting. The actuators were activated by hydraulic pressure: The new al-
Saim’s stabiliser branch offices and workshops are situated in Bologna - North Italy where every product is thoroughly checked and tested in appropriate, considerable basins by highly qualified technicians before delivery.
gorithm and the fact that more than 100 parameters coming from sensors could connect, upgraded considerably the surpassed pre existing system. Hence we dived into the world of stabilisers with ABT TRAC and soon began to supply San Lorenzo, Azimut Ferretti, and Custom Line, because the product was American quality and delivered above average performance”. As the product evolved it could also stabilise at zero speed or when lying to an anchor simply by changing some of the parameters on a touch screen display and by increasing the fins’ surface area. A further evolution soon appeared on the market with the arrival of ABT’S electric actuators rather than the hydraulic ones. Thus etrac or the electric stabiliser was marketed because it performs as well as the preceding model but it is more compact and a lot easier to install inasmuch as there’s no need for pressure pumps nor power-packs. “Winglet designed fins generate 20% more power to dampen roll and 10% less drag when compared to other competing models”, says Donà who goes on: “Alongside this product, by 2004 we had already substituted Max Power propellers with Side Power, a Norwegian producer who
was at a certain point in time manufacturing the whole range of bow and stern thruster props. Soon after, Side Power decided to build their own stabiliser fin systems but with a considerable difference: since their installations can be hydraulic, electric, or both. This last requires a power pack installed in proximity of the electric actuators. Vector Fin’s fins are concave and exploit their peculiar shape rather than the size of their surface area”. In fact they deviate thrust direction in a direction in which the larger part of power contributes to reduce roll and collateral dynamic effects are reduced to a minimum. While cruising or lying to an anchor these concave vertically positioned Fins’ move up/ down rather than only parallel to the keel ‘s angle. Furthermore as the angle of heel changes so does the leverage effect given by the fins. Therefore as the leverage angle of the fins is optimized in this way drag effect is reduced and consequently the same applies to fuel consumption. “The great advantage – adds Donà – is that according to recent studies Vector Fin’s fins sport a foil effect which allow a speed of two extra knots. This was widely appreciated and therefore not only in Italy. Several important brands have since adopted this system. In the foreseeable future fins will be consistently more ‘bent’ with their end section tapering off which will seemingly increase efficiency”. Saim therefore decided to diversify the distribution of products aimed at stabilising superyachts with gyroscopes rather than fins. “In 2008/20009 – which we all remember as very difficult years- In spite of this we decided to offer an alternative solution: Gyroscopes and we obtained the distribution of Seakeeper for a period up until a time when the US company decided to deal directly with the Italian market. Today we’re distributing Veem, a brand which manufactures gyro stabiliser plants for over 35 metre yachts. They’re easy to install during the yachts’ construction phases and also as retrofits inasmuch as they only need electric power supply and water to cool them”. Veem’s most popular current models are the Gyro 120 and Gyro 260. They both feature
vertical axis, they’re more compact with a spinning wheel which is installed into an airtight vacuum which dampens roll up to 95% when the yacht is lying to an anchor or is proceeding slowly. Additionally the “smart torque” software in terms of control is fully patented and equips the Gyro plants allowing maximum reduction of roll if sea condition and boat speed change accordingly, and equals the performance delivered by larger systems featuring passive control. “If personally I were to choose, I believe the best solution entails having both systems installed, a gyro and fins. This has been confirmed by several ship yards as well and on request they install both. Our offer would be decidedly interesting while embracing a vaster section of the market. Let’s then remember that Zipwake can provide maximum ship control”. Their S series is at the forefront. It is currently deploying electrically activated ‘blades’ which face downwards parallel to the yacht’s transom rather than using traditional Flap/trim tabs. The new ‘blades’ craft an efficient deviation to the flow below the hull with reaction intervals that are less than 1.5 seconds. The so called interceptors are also quick to respond inasmuch as the 3D gyro. control system integrated with GPS offers great management potential and precision to the captain. It has been devised for boats from 20 to 100 feet.
ETRAC 250. Stabilising fins have been computer crafted using optimised profiles to obtain maximum lift with minimum drag. The adoption of winglets enhance performance and effectively reduce roll. (model etrac250 in the photo)
Vectors Fins + Side Power Vector Fin’s stabiliser plants ( covered by international patent) maximize roll reduction by 50% when lying to an anchor and up to 30% while cruising. They reduce collateral dynamic effects caused by traditional fins. This fin typology is more efficient on planing hulls measuring between 15 to 22 metres. The fins can be removed from outside.
VEEM Veem gyroscopes Gyro 120 and Gyro 260 well adapt to every type of hull design over 35 metres long. Their choice is not regardless of the yacht’s dimensions, but also to the roll dampening effect required and to the sort of sea condition normally encountered in the areas of choice. The stabiliser plants operate vertically with a vacuum ‘bagged’ spinning flywheel, which further dampens roll up to 95% when lying to an anchor or when the yacht is proceeding slowly.
Traclink TRACLINK controls stabilisers, bow and stern thrusters, and windlasses. It also monitors water temperature and oil pressure. Water pressure function switch is included and additional user functions can be added accordingly. TRACLINK is essentially a plug and play unit and therefore requires a single cable connection to the control box.
Swedish Zipwake distributed by Saim manufactures ‘correctors’ which reduce roll, pitch, minimize drag and compensate excessive ‘angle of heel’ if and when necessary. The firm’s current models are electric and cover boats from 20 to 100 feet. In lieu of traditional flap like fins these plants are equipped with blades which point downwards running parallel to the transom.