Figure 26. Dolos with angled shank-fluke break 



Comparison of Dolosse 

 Armor Unit Movement Data 



Initially, the horizontal and vertical positions of the 101 targeted dolosse dis- 

 tributed along the north and south jetties were evaluated for the 1998 and 1994 

 photogrammetric surveys. Horizontal positions and elevations of the targets, 

 obtained from the stereo models, are shown in Tables 5 and 6 for the 1998 and 

 1994 surveys, respectively. Horizontal data are based on the New Jersey State 

 Plane Coordinate System, and elevations are referenced to mean low water. 



Displacements between the horizontal and vertical positions of the targets 

 established on the north and south jetties are shown in Table 7 for the two 

 surveys. 



An analysis of movement data for the targeted dolosse on the north and south 

 jetties between 1994 and 1998 revealed significantly less movement than 

 detected during previous survey periods. Movement of the dolosse targets in the 

 horizontal (northing and easting) directions ranged from m (0 ft) to 0.54 m 

 (1.76 ft), and vertical displacement ranged from m (0 ft) to 0.07 m (0.22 ft). 

 Only three target positions on the north jetty moved over 0.15 m (0.5 ft) in the 

 horizontal direction. All other target positions on the north jetty moved 0.076 m 



38 



Chapter 3 Current Monitoring Plan and Data Comparison 



