AUTOMATIC STEERING. 55 
alone, with its instantaneous response to minute deviations of course, we have everything 
that is necessary to accomplish the purposes most effectively, even including the “easing off,” 
“meeting,” and full anticipation. 
Of course, in the case of the gyro compass it is not the master which is used direct. 
The master compass is usually mounted below decks. The repeater follows the master with 
an accuracy of one-twelfth of a degree. This minute accuracy with which the gyro compass 
repeater indicates the true course of the ship and the instantaneous response, being probably 
less than 1/100 of a second together with its great directive force, gives opportunity for auto- 
matic steering never before possible. In fact, it may be said that the gyro compass has 
ushered in the era of automatic steering. 
The embodiment of the mechanism for automatic steering has been developed in two 
types, which may be known as the “separate” system, one example of which is shown in Fig. 
1, Plate 1, and the “unit” system, shown in Fig. 3, Plate 2. In each of these figures the 
steering wheel is clearly to be seen in its ordinary position on the bridge. In Fig. 1 a prop- 
erly magnetic shielded motor is shown above, secured to the ceiling. This motor, which in 
the “unit”? system is contained within the pedestal, is reversible and under the control of the 
automatic contact devices operated by the joint movements of the gyro compass and rudder. 
This again receives modification from a device which constantly measures the yaw angle by 
means of which the anticipation and constant suppression of the yawing is accomplished. 
Either of these systems can be employed with any telemotor system, but we prefer the “‘sepa- 
rate” type where a telemotor is not employed. Fig. 2, Plate 1, shows the system mounted in 
the wheel-house of one of the largest tankers, the John D. Archbold, having a loaded dis- 
placement of 32,000 tons. The back end of the handle for throwing the automatic on and 
off is seen at D. 
When the “separate” system is being employed, it is found that a self-synchronous, com- 
pletely automatic helm angle indicator can be used without requiring an extra cable. 
The method of operation of the automatic steerer or “iron quartermaster” is very sim- 
ple. The instrument is capable of being set for response to different amounts of deviation 
from course. It has been employed practically for continuous steering of very large ships, 
and its quite remarkable performance is illustrated by conditions where the response is set 
as close as ten minutes of arc or 1/6° of departure from true course in azimuth. This oper- 
ation is positive in its nature and through the closing of an electric contact calls into action 
the rudder operating mechanism, which simultaneously establishes the helm angle. This, in 
turn, operates a suitable follow-up mechanism by adjustment auxiliaries effecting the proper 
anticipation, and the helm “eased off” and returned or swung to its proper complementary 
angle. The effect of this manipulation is plainly to be seen in the records of Fig. 4, Plate 
3. This particular record was taken as a result of automatic steering of a ship loaded to 
32,000 tons displacement, Fig. 5 being a record of the steering of the same ship while light 
or in ballast. These two represent the most difficult conditions of steering that will perhaps 
ever be met with in one and the same ship, as this is probably an instance of the greatest 
difference possible between loaded and light conditions, in this case bearing a displacement 
ratio of 2.7 to 1. In her light condition she is low aft and with bow well out of the water, 
constantly carrying more or less “helm” when cross wind and currents prevail, yet the 
record gives evidence of the high order of steering secured. 
Referring now to Fig. 3, Plate 2, the gyro-compass repeater is seen at the top of the 
