Tandem Anchor Systems. The predicted anchor drag distance for tandem
anchor systems can be obtained from Table E-2.
1.2.2 LOAD MEASUREMENT. While setting the anchor, it is desirable to monitor the
loads. A currently calibrated dynamometer should be placed in line to measure the
1.2.3 FINAL ANCHOR POSITION. It is expected that the desired holding capacity can
be achieved during setting and that the anchor will be within the 40' long by 20'
wide allowable anchor area (see Figure E-2). If after setting, the desired load is not
obtained, or if the anchor drags outside the tolerance box, then the anchor must be
repositioned and the pull test repeated.
1.3 PULL TESTING. After the anchor is set, the pull test should be conducted. It is
important that a length of chain equal to the total length of riser and ground leg be
used for the test. Use of shorter chain lengths will create an uplift force on the
1.3.1 LOADING PROCEDURE. Each anchor leg should be pull tested independently.
The vessel performing the pull should gradually build up to the proof test load.
Increase the load in 10,000 pound increments up to the required proof test load.
After each 10,000 pound increase allow the dynamometer reading to stabilize.
Once the required pull test load is reached, allow the dynamometer reading to
stabilize, then hold the pull test load for 3 minutes.
Anchor Leg Adequate. If the desired load is obtained and the anchor is
positioned within the tolerance box, the anchor leg is adequate.
Anchor Leg Inadequate. If either the pull test load is not achieved or the
anchor is out of position, the anchor must be repositioned and the pull