NEWS

Performance Requirements for Marine Anchor Windlass

According to the GB/T 4447-2008/ISON4568:2006 standard, the performance of anchors used in the production of ships should meet the following requirements:

1. The specified performance requirements are based on the use of one anchor chain wheel at a time.

2. The windlass should have the ability to work continuously for 30 minutes under working load, and it is required to have the ability to reduced speed and work continuously for at least 2 minutes under the overload tension specified in 4.

3. The nominal anchoring speed of the windlass should not be less than 0.15m/s.  Using standard anchors, and taking the efficiency of anchor chain tubes is 70%, with a buoyancy coefficient of 87%.

4. When determining the performance data of the windlass, the following data should be used:

a．Working load F_w1, expressed in Newton (N), with anchor depth not exceeding 82.5m

——Grade 1 anchor chain: 37.5 d²;

——Grade 2 anchor chain: 42.5 d²;

——Grade 3 anchor chain: 47.5 d².

Here, d is the diameter of the anchor chain, measured in millimeters (mm). Overload tension: 1.5 F_w1. 

b．Workload F_w2, expressed in Newton (N), when the anchor depth is greater than 82.5m

F_w2 = F_w1 + (D-82.5) × 0.27d²

Here, d is the diameter of the anchor chain, in millimeters (mm); D is the anchoring depth, in meters (m). Overload pulling force ≥ 1.5 F_w1.

c．Support load

——Chain stopper: 0.45 ×  Anchor chain breaking load;

——Chain free stopper: 0.8 ×  Anchor chain breaking load.