Testing of Initial Condition Effects; Concern about the effect of starting a ship at a fixed point within a continuous transit led to the testing of the impact of breaking a transit and reinitiating a ship motion with the same controls time schedule. This was tested by reinitiating the autopiloted model transit of the 500-ft channel with a bank multiplier of 3 (model run presented in Figure 15) fifteen minutes into the transit and restarting it with the "measured"(modeled) initial conditions (i.e., rudder, RPM, heading, position, rate of-rotation). The results of this are shown in Figures 16-18. It can be seen that after a brief period ft Channel, Bank Moments x 3 of recovery, the heading, distance off-track, and the rate-of-rotation repeat very closely the same pattern even though the reinitiated model run was not functioning with the autopilot but with the rudder position and RPM as input controls. This seems to imply that the process of setting the initial conditions correctly and feeding in the measured controls should not significantly effect the reproduced ship effects if the forces and moments applied to the ship are the same.

　

　

　

　

 Test of Bank Effects Without Controls; Another test of the simulated channel and ship was performed by setting the rudder to the neutral positions (O deg) and starting the ship with the initial conditions and no rudder control. The response is shown in Figure 19 and indicates that while the ship does not stay aligned with the channel and deviated within the channel

　

 significantly (up to 170 ft or 52 m) it is influenced by the banks to follow the general path of the channel.

　

　

 Real-Time Simulations; Finally, in order to check out the possibility of reproducing the measured ship behaivor (possibly using both the New Amity and the SKS Trinity measurements) real-time transits were recorded for two different pilots. These tests were performed on the new USAE simulator with the 500-ft channel model. Neither the ship nor the channel models have been verified by local pilots. Results of these runs are shown in Figures 20-23.

　

 Much larger rudder controls were used to control the ship with real-time piloted simulation. The second pilot observed the first pilot's runs and observed several locations where the ship experienced significant shear and therefore, was prepared to respond aggressively at the first sign of these shears. The first pilot used 15-20 degrees of rudder, with maximum rudder used periodically, to keep the ship on the channel heading and within 60 ft (18 m) of the channel centerline with the banks at 1.5 multiplier. With the bank effects having a multiplier of 2, the deviation off centerline was mostly on the port side of the channel and went up to 120 ft (36 m) away from the centerline.

　

 The second pilot generally used maximum rudder at three points to overcome shears for both channel models. These shears occurred near the start of the run,just below markers 59-60, and near the end of the run below markers 73- 74. The pattern of control was similar for both runs and the ship deviated from the centerline over 100 ft (30 m) at the end of the run. Between markers 59-60 to 71-72, there was little control required with rudders of less than 10 degrees required both port and starboard.