KNOW Everything you need to know about onboard hydraulic systems

The applications of on-board hydraulic systems are many.
For a cruising hull, up to 50 feet, usually only backstay and vang are found. For larger hulls also the tesabase. On purely racing hulls over 50 feet and with a carbon mast, mast jacks for mast adjustment are also beginning to be found. On maxi yachts the stay adjuster, a system that adjusts the forestay tension, can also be adopted.

Can hydraulic systems be installed on any type of boat?

Theoretically, yes, but to get an idea of size, it can be said that hydraulic systems can be useful on boats as small as 40 feet. This is because normally loads on lower boats can be easily supported and maneuvered by mechanical systems. Another reason, concerns the footprint: it is obvious that to mount a hydraulic system there is a need for space where to install the components, and usually on boats smaller than 40′ there is not enough space available.

Where can they be mounted?
For cruising boats, and precisely starting from the size of 40 feet, the first hydraulic system that is adopted is the backstay, followed by the vang, and finally the tesabase, as the size of the boat increases.

thumb_440x293GDVDICGENPAG94_03Can I also later substitute a mechanical maneuver into a hydraulic one?
Yes, each maneuver can be replaced when desired. Certainly the easiest system to change is the backstop. In this case, in fact, an integral hydraulic model is installed, that is, with the pump integrated into the cylinder. With this solution, no control unit has to be mounted, and the adjustment is made directly on the cylinder. For other systems, such as vang and tesabase, the work is more complicated because it requires the use of a control unit and the passage of oil connection pipes. But if for vang you can sometimes easily find a solution, for tesabase the matter becomes a bit more complex. Sometimes modifications can be made to the existing boom so that a hydraulic cylinder can be placed inside it. But if such an operation is not possible, the boom must be replaced.

Is there a size term for whether vang is better plumbing or not?
Of course, there are load limits. To get an idea, on boats over 60 feet it is almost always necessary to adopt a hydraulic system, as mechanical vangs with sufficient thrust to support the weight of the boom are not available on the market.

thumb_440x351GDVDICGENPAG94_02What does a complete plumbing system consist of?
Taking a 50-footer with hydraulically controlled vang, backstay and tesabase as an example, the typical system involves a control unit, usually located in the cockpit, that controls all three maneuvers (see image above). It usually consists of a single valve that controls the three functions, (just move the switch on the shunting), a pressure gauge that indicates the loaded pressure, and a button to release the shunting. To “pump” you have a removable lever in the manual version or a hand control in the electric version. Optional features include the Quick Release, an emergency button mounted on the deck, within easy reach of the helmsman, which allows for complete release of the vang with the press of a foot.

What kind of maintenance do they need?
Plumbing systems tend to be maintenance-free; check the condition of the pipe fitting seals periodically; they are the only weak point in the system, and their rupture or deterioration could cause oil leaks.

thumb_440x293GDVDICGENPAG94_04What is mast jack?
It is a hydraulic piston, located in the foot of the mast and disengaged from the normal on-board hydraulics, which is used during “masting” to give the right tension to the rigging. is a system frequently used on racing boats because of its precision in tension adjustment. As a rule, the maximum load to be applied to the piston should not exceed 20% of the maximum allowable load on the rigging and should be specified for each boat by the manufacturer. There are two systems of shaft lifting by Mast Jack: the first with a through-bar connected to two lifting pistons on the side of the shaft; the second with a single piston fixed inside the shaft and connected to a pump. In any case, it is essential that the foot of the tree be supported over its entire surface to avoid asymmetry and damage to the structure. To get an idea boats like the Grand Soleil 46 or the Swan 45 in the regatta version with the carbon mast have the Mast Jack.

If I want to put on just the backstay, do I have to turn the whole boat upside down?
No, by adopting an integral system, it is sufficient to change the backstay, and possibly shorten the forestay to fit the length of the new cylinder. As we said before, the system is integrated of pump.

How much does the vang and backstay system cost for a 40-foot boat?
Obviously, the final price depends on whether the boat is prepared for the installation of a hydraulic system or not. There are then different versions of systems to be adopted, but generally speaking, they start at an expense of about 2,300 euros for the integral tensioner alone, and go up to 12,000 euros for a system with a control unit.

This “interview” is from our best-selling volume “Practice & DIY,” already in its third reprint! A special issue dedicated to lovers of board work, 132 pages of valuable advice. In the first “Getting to Know You” section, the complete collection of our “Boat Interviews.” In the “Sailing” section, on the other hand, we guide you once you have put out to sea to learn how to maneuver with a small crew, at night or in rough seas. Not forgetting how to anchor smoothly or prepare the boat for winter and then testing yourself with a quiz to see if you are a good skipper. Finally, in the “Learning” section, here are no less than 61 questions and practical tips to test you. You can read the answer right away or attempt to answer it and then check your level of preparation. Here topics are divided into four categories, from the use of accessories and equipment to useful tips on weather and maintenance, from sailing maneuvers to never having trouble in port.




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