How to Carry Out Daily Inspection and Maintenance of Anchoring System?

Anchoring system is an indispensable part of marine equipment. When the ship is docked, it is necessary to throw the anchor through the windlass, and the anchor is fixed by the anchor’s grip and the weight of the anchor chain itself, so that the ship can maintain the hull. However, the long-term use of the anchoring system will inevitably lead to various problems. Therefore, the daily inspection and maintenance of anchoring system are very important.

Finished anchors should all be inspected, weighed and tested visually without being painted.

1. Appearance Inspection

There should be no cracks, notches, slag inclusions or defects affecting the performance of the anchor on the surface of the finished product, and welding repair is allowed for surface defects that do not affect its strength. The weight of the anchor head (ordinary stockless anchor) (including the weight of the pin shaft and accessories) should not be less than 60% of the total weight of the anchor, and the deviation between the actual weight of the anchor and the nominal weight should be within ±7%.

2. Pulling Test

The stockless anchor pulls two claws at the same time (the test is to be carried out on both sides of the flip); the two anchor claws of the rod anchor are tested separately. The tensile load shall be carried out in accordance with the specifications.

Before the test, marks should be made on the tip of the anchor claw and the anchor rod of the anchor shackle, so as to measure the distance before and after the test; during the test, the tensile force should be added to 10% of the test load, the distance should be measured and recorded, and then the tensile force should be added to the test. 100% of the load, after holding for 5 minutes, gradually reduce the tension to 10% of the test load, measure and record the distance. The residual deformation of the rodless anchor should not exceed 1% of the gauge length, and the anchor claw should be able to flexibly rotate to the maximum designed angle. Rod anchors should have no obvious residual deformation.

3. Grip Test

High holding power anchors and super holding power anchors shall be tested at sea. The holding power of high holding power anchors shall not be less than twice the holding power of ordinary rodless anchors of the same weight; the holding power of super holding power anchors shall not be less than the same weight. 4 times the holding power of ordinary rodless anchors.

4. Test of Anchor Chain

The finished anchor chain is to be subjected to tension and breaking tests as specified in the presence of the surveyor. Paint or anti-corrosion coating shall not be applied to the anchor chain before the test.

5. Tensile Strength Test

In knots, the test shall be carried out on an approved tensile machine according to the specified load, and the elongation shall not exceed 5% and there shall be no obvious defects.

6. Pull-off Test

Choose an anchor chain from each batch of anchor chains with no more than 4 sections, and cut not less than 3 links for testing. If the breaking load is less than the specified breaking load, it is unqualified.

7. Test of Windlass

The windlass shall be capable of twisting a single anchor from 82.5m to 27.5m, and the average anchoring speed shall not be less than 9m/min; the anchor chain shall be released quickly and braked 2-3 times, and the anchor chain shall not slip out or skip the chain on the sprocket. and the phenomenon of unstoppable braking; and after the anchor is dropped, the chain brake should be braked tightly, and the ship should slowly reverse for a while to check the function of the chain brake.

Regular inspection and maintenance of anchor system should be carried out at least once every 6 months.