Dave Gerr - Boat Mechanical Systems Handbook-How to Design, Install, and Recognize Proper Systems in Boats

the outboard rudder of an old 23-foot (7 m)

Speedway launch.

Rudder Feedback: Rudder

Angle Indicators

Sailboats and powerboats with cable steering

(and four or fewer turns lock-to-lock) can pro-

vide the helmsman with a reasonable indication

of the rudder’s position. This is done simply by

marking the wheel (perhaps with a Turk’s head)

at rudder dead center. This indicator and a

memory of how the wheel has been turned

gives the helmsman a good feel for rudder

position.

Larger boats and those with hydraulic

steering should be fitted with rudder angle in-

dicators at the helm. These come in a wide

variety of sizes and types to give a precise, in-

stant readout of the rudder angle port or star-

board. A sender/sensor on the tiller arm or

quadrant relays the angle information to the

indicator display at the helm.

Autopilots require constant information on

the exact rudder angle as well as course and

speed. Feedback from the rudder angle is criti-

cal to proper autopilot operation. In most in-

stances, the rudder angle sensor on the autopi-

lot will also provide a readout to the helmsman.

Alternate Steering Gear

There are other steering systems besides

simple cable and hydraulic systems. Wheels

can be attached to rack-and-pinion steerers

or worm-gear steerers. These are both solid

machined units that give rugged service and

the mechanical advantage needed for large

rudder loads. Rack-and-pinion steerers pro-

vide positive helm feel or feedback from the

rudder like cable steerers.

Worm-gear steerers are intended for

larger vessels. They were, in fact, first com-

mon on large coasting schooners. Their ad-

vantage is that the wheel stays exactly where

you leave it when you remove your hands—

instant, automatic helm lashing, which can

be quite convenient. The drawback, though,

is that this eliminates all helm feel or feed-

back from the rudder. Both rack-and-pinion

steerers and worm-gear steerers also have

the same disadvantage as a tiller: they must

be attached almost directly to the rudder

stock aft.

A relatively recent twist on cable steer-

ing—not much more than 45 years old—is pull-

pull or conduit-cable steering (Figure 12-17).

It functions the same way as standard cable

steering, but consists of cables sliding within

flexible conduit instead of running over

sheaves. This permits you, theoretically, to

run the pull-pull cable any which way, as with

hydraulics. In reality, there are limits. Pull-

pull cable steering is a good solution for rel-

atively small boats (under 35 feet or 10 m),

in installations where bends can be kept to a

minimum. Then you can run the pull-pull ca-

bles almost as easily as hydraulics. There’s

PART FOUR:RUDDERS AND STEERING SYSTEMS

Figure 12-17.
Pull-pull or
conduit-cable
steering (Courtesy
Edson Corp.)