58 AUTOMATIC STEERING. 
DISCUSSION. 
THE PRESIDENT:—Gentlemen, you have heard this paper, No. 1, on “Automatic Steer- 
ing,’ by Mr. Sperry. It is now open for discussion. 
Mr. Ropert H. Rocers, Visitor:—We will all agree that a continuous, insidious loss of 
fuel and time always goes with hand steering of ships. 
Crude and simple records made on sea voyages of five ships are confirmed by the more 
refined methods of observations made possible by the various Sperry instruments operated 
from the gyro compass. 
A continuous helm of 6 degrees is shown by Mr. Sperry in a specific case to set up a drag 
of 9,300 pounds. This would equal 356 tow rope horse-power, 500 brake horse-power, or 
16 per cent of the available power of the ship’s engines. 
On a ship using 100 barrels of fuel oil per day, imagine the captain and chief watching 
sixteen barrels being poured over the rail every afternoon. That loss would be obvious 
rather than insidious. In addition, if the innumerable checks to the speed were concen- 
trated into a dead stop of an hour and more each day, the matter would be thoroughly over- 
hauled. 
While there is a good reason for better hand steering to a gyro than to a magnetic com- 
pass, due to the former’s quicker and more complete action on small angles, still the differ- 
ence between the work of first class quartermasters and poor but still acceptable quarter- 
masters is so great that the slight improvement possible in each case still leaves average steer- 
ing a heavy source of loss. 
On the twin-screw S. S. Virginia with magnetic compass in one hour, under precisely 
similar conditions, one quartermaster used 84 degree-minutes of helm while his successor used 
254 degree-minutes, an increase to 300 per cent. 
On the motor ship Missourian, with gyro compass, one quartermaster used 850 degrees 
total helm movement per hour with a maximum helm of 6.4 degrees, while another under 
the same conditions used 1,114 degrees, or over three complete revolutions with a maxi- 
mum single angle of 16 degrees. 
As Mr. Sperry states, yawing can be kept to a minimum when outboard ranges or ob- 
servations are available to the quartermaster, who then only occasionally refers to the com- 
pass for the course. 
The most accurate index of yawing, both as to instant of beginning and total amount, 
that I have found is in the simple expedient of referring to a fine line connecting the ship with 
a small drag towed in the wake. Such a line lies in the course made good, and its angle with 
the axis of the ship reflects accurately and instantly every deviation. 
Mr. Sperry emphasizes the importance of a guiding element that is instantly and 
minutely responsive, to be employed as the base line so that the slightest departure from 
the course may be utilized to apply the correction in order to make automatic steering prac- 
ticable. He also refers to the futility of trying to use a magnetic compass for this func- 
tion and cites the proposed use of highly complicated BIOSIS elements as the other 
extreme. 
This leaves an opening for the introduction of a proposed means for automatic steer- 
ing, known as the wake system, in that the base line is the before-mentioned line towed in 
the wake of the ship. In the case of a small motor boat, the stiffness of the line against de- 
flection by yawing is sufficient when properly connected to produce a prompt and proportion- 
