Gyrostabilisers produce up to 99% roll reduction. I wish I could claim 100% but that’s not true. The roll reduction varies with the wave height, the wave period and with the characteristics of each vessel. Typically in up to moderate seas you’d be expecting to get 60-70% roll reduction. As the sea state increases that reduction will back off slightly. We size our systems effectively to produce similar performance to a fin system when underway, and then when the vessel is travelling slowly, or at rest, the performance is just outstanding, you literally do get 90% roll reduction.
The selection of gyrostabiliser size for various superyachts depends on the displacement of the yacht,the GMT and the wave profile. A heavier yacht with a higher GMT requires a bigger gyrostabiliser.
The most accurate way to find out which VEEM Gyro size you need is to fill out the VEEM Gyro Size Calculator. This calculator will give you an instant report based on your vessel information.
A VEEM Gyrostabiliser can be mounted anywhere on the vessel within structural reason. Effectively anywhere where there is adequate structure in the ship to hold the gyrostabiliser down it can be mounted. It does not need to be mounted on the vessel centerline. VEEM Gyrostabilisers do not need to be mounted low in the vessel. Preferably we would mount them aft of midships just to avoid slamming accelerations, but they can be mounted forward. So really there’s no limitation to where the gyrostabiliser is mounted. I think typically they’ll be mounted in the engine room because there are structural supports already in place, there’s lagging in place, and there’s power and other auxiliary systems already in the location.
The VEEM Gyrostabiliser is driven by an electric motor, so they require a three phase power supply. The power requirements vary with the size of the unit, but typically that power is a small fraction of the power consumed by the thrusters. Our experience has been that there is more than adequate power available. If you contact us, we’ll come back to you with what the power requirements are for a system suitable for your vessel.
VEEM Gyrostabilisers vary in size and weight depending on the size and weight of the vessel. Typically a small Gyrostabiliser system will weigh approximately 2.5% of the displacement, or the weight of the boat. And a large system would weigh in the order of 5% of the vessels displacement. The small versus large decision really depends on what the requirement for the Gyrostabiliser is. If it is a complete stabiliation system for rough weather at speed, then you might be looking at a weight of 5% of displacement, and if it’s just to keep the boat from rolling in moderate to small seas, then you might use a 2.5% of displacement installation. If you contact us then we can come back to you quickly with an estimate of what’s required.
VEEM Gyrostabilisers produce large torques in a small space, and that is the beauty of the device. That means that the gyrostabiliser needs to be mounted on structural mounts similar to engine beds. My advice is to contact us with information about your vessel. We will then send you back the loads that you will expect to see on your vessel. Then it would be best to contact the shipyard that built the vessel, or contact a consulting naval architect that will provide you with information as to the sizing and design of the mounts.
Obviously there is a lot of kinetic energy contained in a VEEM Gyrostabiliser flywheel, so it’s a key aspect of the design of the unit. The VEEM Gyrostabilisers flywheels have been designed with infinite structural fatigue life. In addition to that, the aluminum housing that surrounds the flywheel itself has a very small gap between the flywheel and the housing, if there was a crack to form, it would be contained very quickly. In addition to that a key part of the bearing monitoring system are two vibration monitoring accelerometers. Those accelerometers monitor both bearing frequencies and also out-of-balance frequencies. If there was any cracking in the flywheel, that out-of-balance would very quickly show up and the unit would shut down. Having said that, with an infinite fatigue life design, the chances of that happening are remote at best.
VEEM Gyrostabilisers have no significant impact on pitch motion. They can’t be used to reduce pitch motion and they don’t produce pitch motion. So they’re really just an independent device that is focused on controlling rolling motion. If there is a significant pitch issue on a new build design or a retrofit vessel then we would assist you with other means of controlling the pitch.
The startup time for the VEEM Gyrostabilisers vary with the product size. For the VEEM Gyro 120, which is the smallest in our current range, the startup time is forty-five minutes to operation and then another five to ten minutes before it reaches full speed.
We provide annual service schedules and task lists for the VEEM Gyrostabilisers. These are routine maintenance items. We don’t expect any servicing outside of that annual requirement. In time, the bearings in the gyro may need to be changed out; however that will be indicated by the monitoring system and be planned as required.
One of the big advantages of a VEEM Gyrostabiliser as a stabilisation system is that there is no penetration through the hull. This means that all installation, service and maintenance tasks on a gyrostabiliser can be carried out with the vessel in the water. That means that there are no tasks added to the typically busy dry-docking schedule and gyrostabliser tasks don’t have to be scheduled with a dry-dock.
A VEEM Gyrostabiliser has no noticeable effect on the steering of the vessel. There are some very small theoretical forces in the yaw axis, which is the steering axis. However, these are not noticeable and have no impact on the steering at all. As the VEEM Gyrostabiliser produces damping, which is effectively a passive force on the vessel, the VEEM Gyrostabiliser can work with the autopilot either on or off, with no special tuning of the autopilot. It really has no impact on the autopilot except that it improves course keeping by reducing the yawing produced by rolling.
The VEEM Gyrostabiliser is a roll axis damping device. It dramatically reduces both roll angles and roll rates, independently of any affect on the pitch axis or the heave axis. Pitching motion that is felt by the vessel will not be affected by the gyrostabiliser and likewise, will have minimal impact on the performance of a gyrostabiliser. Likewise, heaving motion is not impacted by the gyro and won’t impact the gyro.
VEEM Gyrostabiliser’s are delivered with an annual maintenance task schedule. These tasks are standard hydraulic system maintenance tasks as would be included on most hydraulic systems. Outside of the hydraulic system, there is virtually no maintenance required. The annual maintenance can be completed wholly whilst the vessel is in the water. This means that there are no dry-docking tasks that are to be added to what is typically already a compressed dry-docking schedule. Down the line maintenance may include bearing change-outs. Bearing change-outs would be indicated by the bearing monitoring system and will be driven very heavily by the operational profile of the vessel.
VEEM Gyrostabilisers are easily retrofitted to any vessel. Because the gyro produces a pure damping force, it doesn’t interact with other stabilization systems if they are fitted. It doesn’t interact with the autopilot system and therefore, there is no programming or software interfaces required with other parts of the vessel. The only requirement for retrofitting a VEEM Gyrostabiliser to your vessel is to find space for it. Preferably, this space would be the engine room. VEEM Gyrostabilisers can be fitted as one single unit or as multiple units, so there are a range of options for either identifying a number of small spaces or one big space for the gyrostabiliser to be located.
Happily, VEEM Gyrostabilisers work best when the roll motion is at its worst. Gyrostabilisers are fantastic at eliminating what we call harmonic rolling, which is rolling due to the fact that the vessel’s natural roll period is somewhat close to the wave period at the time. Outside of this, the performance reduces but then so does the rolling. So what we typically find is that over a broad range of operational conditions the damping of rolling is very high.
A VEEM Gyrostabiliser is a roll damping device that produces the same roll damping torque when the vessel is underway in rough water, in smooth water, or at rest. So, the gyro is performing the same task, regardless of the operation of the vessel. This is similar to zero speed roll fins. There are, however, some substantial differences between the two systems. A VEEM Gyrostabiliser is a single piece of equipment, or can be multiple pieces of equipment if you choose. It is located in the engine room. It is extremely easy to integrate into the vessel because it is in one location. There are no auxiliary systems that need to be run through the vessel and the whole piece of equipment can be mounted in the engine room, which benefits from the lagging that is contained in the engine room. A gyrostabiliser has no hull protrusions. So, there are no moving parts outside the hull. This is a big advantage when you are drifting or anchored up and you have swimmers in the water. There are no moving parts outside the hull, so there’s no chance of any danger to any swimmers. A VEEM Gyrostabiliser produces no drag because there is nothing in the water. So there’s obviously a substantial advantage when you are underway because increasing speed does not increase your drag.
In summary, when comparing a VEEM Gyrostabiliser to Zero Speed* roll fins, a gyrostabiliser is a single piece of equipment or multiple pieces of equipment if you choose. However, they are all located in the engine room and are very simple to integrate into the vessel. There are no auxiliary systems running forward into the staterooms that could cause noise and the lagging in the engine room means that the noise of the gyrostabiliser is barely discernible at best. A VEEM Gyrostabiliser has no parts protruding through the hull. Therefore, there’s no added drag underway, which is obviously significant and more significant for high-speed vessels. Also, there can be no potential damage to swimmers in the water with the gyrostabiliser operating. A gyrostabiliser, as it has no protrusions outside the hull, can have all maintenance tasks carried out with the vessel floating. Therefore, there is no requirement to add gyrostabiliser maintenance tasks to the already compressed dry dock schedule.
* Zero Speed is a Trademark of Quantum
A VEEM Gyrostabiliser can be installed alongside an existing roll fin stabilisation system. That could be a traditional roll fin stabilisation system or it could be a Zero Speed* roll stabilisation system. Because the VEEM Gyrostabiliser produces a pure torque, it does not interact in any negative way with any other control systems on the vessel. So it can be integrated with, for instance, trim flaps, T-foils, roll fins or really any form of stabilisation system. There is no contamination of the control being produced by the other systems.
* Zero Speed is a Trademark of Quantum
All stabilisation systems are currently treated as a comfort system, rather than a safety system, by International Classification Societies. Therefore there are limited Rules surrounding stabilisation systems. However the VEEM range of Gyrostabilisers has been designed such that, if required, type approval for the device can be sought. If you are interested in Type Approval then certainly speak to us and we can deliver that with the product.
The VEEM Gyrostabiliser is fairly simple piece of equipment. There are options available to select. These would include for working commercial vessels a motion monitoring system that provides a traffic light, go, no-go indication for various operations. That’s obviously programmable by the user. There are ways of mounting our range of stabilisers which we see as a benefit. One is you can sling the precision bearings between two girders which allows you to mount the whole Gyrostabiliser right down on the hull which obviously reduces vertical space requirements. Or you can simply mount the Gyro Stabiliser on soft mounts at the base of the gyro.