By Tom Burden
Hydraulic steering makes handling high-torque engines and high-speed boats easy and safe. Feedback is eliminated and holding a steady course is simplified because no steering effort is required until you actually want to turn the engine or rudder. We offer quality hydraulic steering in complete, easy-to-install packages. We stock components to fit virtually any pleasure or commercial boat’s hydraulic steering needs.
Two-line manual systems (BayStar, SeaStar): in these systems the helm pump moves the hydraulic cylinder directly. In use, a clockwise turn of the steering wheel will send fluid from the helm unit into the starboard hydraulic line. This fluid will be pumped into the cylinder and either extend or retract the cylinder rod. Incoming fluid pushes a piston which is pinned to an external rod. As the piston is moved the rod is either extended or retracted, and the boat turns. Outgoing fluid from the other end of the cylinder is returned to the helm via the port side line.
Three-line manual systems (Hynautic): three-line systems are pressurized and contain a separate reservoir and pressure-relief valve. Common on work and pleasure vessels up to 70'. Helms are simpler, since they do not contain the reservoir or relief valve. Fluid fill at remote reservoir, instead of the helm. They use soft refrigeration type copper tubing, instead of nylon hose.
Power assist: for outboards 150hp and above and for twin and triple engine applications, bass boats, pontoon boats, power catamarans and inboard cruisers without engine-driven power assist. Uses an electronically-controlled on-demand hydraulic pump to give your boat the same easy steering you are accustomed to in your car.
Power steering: larger boats require a bigger system that can handle higher loads typically experienced at the rudder(s). Power steering systems include two distinct operating circuits:
The manual circuit provides the control portion of the steering system, and the power circuit provides the power to turn the rudders. See the diagram of the new Optimus 360 system, which is NMEA 2000 compatible and uses a joystick control.
There are two basic parts to a hydraulic system: the helm and the cylinder. More complicated systems may have fluid reservoirs, specialized valves, relief valves, autopilot pumps, etc.
The helm consists of a hydraulic pump and a system of valves, which pumps fluid into the hydraulic lines. The pump is activated by turning the steering wheel, which causes a “swash plate” to press on a series of small piston pumps. The use of small pistons and ball bearings makes the pump action very smooth—nothing like a normal piston pump. The internal valve assembly acts as a check valve, preventing the outgoing fluid from returning, while effectively eliminating kickback to the wheel. In systems like the popular SeaStar and SeaStar PRO, the helm serves several functions, incorporating a hydraulic fluid reservoir and a relief valve as well. Some systems have a helm, reservoir and relief valve as separate components.
In use, a clockwise turn of the steering wheel will send fluid from the Helm Unit into the starboard hydraulic line. This fluid will be pumped into the cylinder and either extend or retract the cylinder rod. Incoming fluid pushes a piston which is pinned to an external rod. As the piston is moved the rod is either extended or retracted, and the boat turns. Outgoing fluid from the other end of the cylinder is returned to the helm via the port side line.
Selection of the proper components is relatively easy, since the number of components is limited. Select the SeaStar 1.7 helm for boats to 40', outboard engines with up to V-6 engines, and speeds to 50mph. For boats with larger outboards to 300hp and speeds over 60mph, select the SeaStar PRO. It operates at pressures up to 1,500psi, and offers the best steering control and reduced wheel walk and chatter. Its increased 2.0cu.in. displacement provides faster steering response, with slightly higher helm effort. The SeaStar regular helm is available in 2.0 and 2.4cu.in. displacements for boats with larger cylinders or special needs.
Bezel/back plate kits: allow for reduced helm protrusion from the dash, and allow retrofitting of SeaStar front mount helms to boats in which mechanical steering or older SeaStar systems were previously installed.
Tilt steering: available as an option for BayStar, SeaStar and SeaStar PRO, but not available for Capilano or Hynautic systems. Replace the standard helm with a tilt model.
The cylinder: consisting of a ram, bored cylinder and attaching hardware, the cylinder is moved by fluid pumped from the helm when the wheel is turned.
The current generation of outboard-mounted cylinders makes installation easy, since they use the tilt tube of the engine for support, and act directly on the engine’s steering attachment point. In other words, the cylinder acts between two points on the outboard, and exerts no force on the boat’s hull or deck.
This type of cylinder is what is known as a balanced cylinder, meaning that port and starboard deflections take the same amount of hydraulic fluid. This, in turn, makes it ideal for autopilots, since they act symmetrically port and starboard. Note that some older BayStar steering kits (HK4200 and HK4230) use an unbalanced cylinder, and cannot be used with autopilots.
There are a wide variety of inboard and sterndrive cylinders available to fit practically any boat, but selecting the right ones can be tricky. SeaStar Solutions (formerly Teleflex) offers extensive technical help at their web site, www.seastarsolutions.com, which will guide you step-by-step through the selection process. And, of course, please contact us if you need more information.
Several helm displacements and cylinder choices are available (except for SeaStar PRO) for a choice in the number of lock-to-lock steering wheel turns, so you can tailor the system to fit your boat’s handling characteristics and your individual driving style.
Steering Hose: special hydraulic hose that carries the fluid from the helm to the cylinder and back. Outboard steering hoses are pre-manufactured to specific lengths. Modification after manufacture is not recommended and could result in steering failure. (Tubing is used in some I/O and inboard hydraulic systems.)
Tie Bar Kits: Hardware to allow steering connection of two or three engines in unison. Some systems use a mechanical tie bar, some a drag link fitted to fixed-mount cylinders, and some connect the engines or rudders using a liquid (hydraulic) tie bar.
Autopilot: installation requires a pump that is teed into the hydraulic system. Some systems require that you add a third hydraulic line (called the compensating line). The SeaStar Add-A-Station Autopilot Fitting Kit (HF5501 for outboards or HF5502 for stern drives or inboards) contains hardware for this. Some autopilot installations also require a rudder position sensor.
Not recommended for use with high performance, 150HP engines (such as Mercury Optimax 150HP engines) or single engine, high-speed boat (such as bass boats). Not for smaller HP outboard engines that use wing nut type transom mount clamping screws.