| A proper steering system is a
critical factor in achieving good boat handling performance and safe
operation. Engine horsepower, proper torque, hull design and boat
speed, in their varied combinations exert loads on steering systems.
The resulting steering forces vary considerably from boat to boat and
motor to motor, therefore you must take extreme care to ensure that the
steering system you select matches your application.
The following guidelines will assist you in
making a steering system selection, and in particular, alert you to
potential problem areas.
- With an increase in speed and
horsepower, steering forces increase considerably. High
performance boats often leave and re-enter the water, momentarily
creating high shock loads on the steering system. Additionally,
certain hull designs may have a tendency to lose stability at high
speeds, a condition commonly called "chine walk".
- The speed at which instability begins to
occur varies significantly among different type boats. A Hardin
Marine twin cable or hydraulic steering system is generally recommended
for boats moving at higher speeds.
- The torque of large outboard motors may
cause a boat to veer sharply from a straight heading or make it
difficult to bring out of a turn. Mechanical steering systems must
have appropriate mechanical advantage for ease of operation, and the
steering cable has to be installed free of kinks, sharp bends or
obstructions, to permit the boat operator to maneuver the boat readily
at any speed.
- Corrosion of steering cables can lead to
stiff operation, complete seizure, and/or loss of steering control.
The steering cable should be regularly inspected for cracks or cuts.
If found, the cable should be replaced. If there are no signs of
cracking, the cable output end and the engine tilt tube should be
cleaned thoroughly, coated with a quality marine lubricant, then
properly reassembled and maintained according to the engine
manufacturers specifications. Corrosive buildup can be minimized
through this simple routine maintenance. Whenever possible, the
boat builder and/or dealer should select Hardin Marine cables which all
have stainless steel output ends to reduce corrosion, especially on
boats used in salt water. Even then, if a boat is not going to be
used for extended periods of time, it is recommended to completely
remove the cable output end from the thru-tube and properly prepare for
storage.
- The routing of steering cables is also a
very important consideration. Multiple bends in the cable and
small bend radius will contribute to cable backlash and steering
inefficiency. Cables should be routed with as few bends as
possible and with the optimum radii achievable.
- Excessive cable length results in
excessive backlash and cable inefficiency. If an installation
requires a 14 foot cable, a 14 foot cable should be used. Do not
add unnecessary length.
- Larger boats with displacement hulls and
inboard rudders can create steering loads that exceed the capability of
mechanical steering systems commonly used on runabouts. Hydraulic
steering systems are better suited to function under high steering
loads.
- Generally Hardin Marine mechanical
steering systems can be used on boats up to 35 feet in length, with a
maximum working tiller arm load of 300 pounds rotary.
- Some high performance boat engine
combinations develop steering instability at high speed.
Instability becomes more prevalent in boats faster than 50 MPH. A
twin cable system or a hydraulic steering system is recommended for
these types of boats.
- Hydraulic steering is recommended for
all boats, not equipped with power steering, that have a working load of
700 pounds rack or more at the tiller end.
- Maximum steering wheel diameter is 16".
- Hardin Marine mechanical steering
systems should not be used on boats equipped with engines that exceed
the maximum horsepower rating of the boat.
|
WARNING
Although Hardin Marine Cables and
Controls designs and manufactures steering systems that meet or
exceed all existing industry standards, it should be noted that some
high performance boats equipped with high performance accessories
such as motor jack plates and high performance propellers, can
generate steering loads far in excess of the 300 pounds at the
tiller end. It is MANDATORY that boats equipped with high
performance equipment or accessories be water tested to insure that
steering loads are within safe operating limits. For more
information, refer to the instruction sheet or contact Hardin
Marine. |
For the best possible results, plan your
cable routing by the most direct route possible. Bend radius should
be 8" or more. Keep the number of bends to a minimum. In any
case, do not bend the cable less than the minimum specified bend radius.
Trim settings of outboards and stern drives can markedly affect steering
loads and maneuverability of your boat. Motor trim tabs should be
set according to the motor manufacturers recommendations. After
installation, test your boat for ease of steering though the full range of
motor trim angles. Varying trim angles can change steering loads on
any given system. Mounting position of an outboard can also affect
steering loads and boat handling characteristics. Strictly adhere to
the mounting specifications established by the boat builder and engine
manufacturer. |
