Chain dimensions and calibration

Chain dimensions and calibration, and therefore the gypsies that will accept them, vary considerably according to whether they are made to imperial or metric standards and even between manufacturers. The European made chain is to DIN 766 and/or ISO4565 and most European gypsies will accept it. There is a strange anomaly that has caught out many owners. The dimensions of the two standards are identical for all chain sizes except 10 mm, in which the link length is 2 mm different. The gypsy should be marked in some way to identify to which standard it conforms.

Suppliers normally proof test chain to between 40% and 50% of the rated Minimum Break Load (MBL), whereas the quoted Safe Working Load (SWL) is 25% of the MBL.

Note that many other standards exist for short link non-marine chain whose dimensions are different. Chain to these standards will not fit any gypsies.

American chain is made mainly to ISO G30 and G43 standards with longer links that may not fit European gypsies. Note that the dimensions of these two grades are not the same. G43 (Grade 40) is more widely used for anchor rodes in USA.

European dimensions (all millimetres except where shown)

Grade 30

Wire sizeABCSWL, kN (tons)UTS, kN

(tons)

 Weight

(kg per m)

 
6618.584 (0.4)16 (1.6) 0.85DIN 766 and ISO4565
724.4 (2.44) 1.1DIN 766  and ISO4565
8824127.5 (0.75)30 (3.0) 1.45DIN 766  and ISO4565
1010281412.5 (1.25)50 (5.0) 2.3DIN 766
1010301412.5 (1.25)50 (5.0) 2.3ISO4565
1212361817.5 (1.75)70 (7.0) 3.8DIN 766  and ISO4565

 

Grade 40 

from maggio catena

Wire sizeABCSWL, kN (tons)UTS, kN  (tons) 
6618.596.75 (.675)27 (2.7)DIN 766  and ISO4565
77.75 (.775)31 (3.1)DIN 766  and ISO4565
882410.510 (1.0)40 (4.0)DIN 766  and ISO4565
1010281412.5 (1.25)50 (5.0)DIN 766
1010301215.5 (1.55)62 (6.2)ISO4565
1212361522.5 (2.25)90 (9.0)DIN 766  and ISO4565

 

Grade 70

Wire sizeABCSWL, kN  (tons)UTS, kN (tons) 
882414 (1.4)70 (7.0)DIN 766  and ISO4565
10102822 (2.2)110 (11.0)DIN 766
10103022 (2.2)110 (11.0)ISO4565
12123631.6 (3.16)158 (15.8)DIN 766  and ISO4565

 

I use and recommended AQUA 4 CALIBRATED chain 

AQUA 4 and AQUA7: when the base model is already outstanding

AQUA 4 and AQUA7: when the base model is already outstanding.In the last few years, European technical standards have set the mechanical and dimensional features of anchor chains for the boating industry and have always based the mechanical strength standard to a tensile strength equal to 30kg per mm2.

MaggiGroup® has elected to increase the quality of its standard anchor chains to a tensile strength of 40kg per mm2.

Thanks to the careful selection of special steels and high quality processes, MaggiGroup® basic products exceed industry standard mechanical performance!

This is why we have decided that, from today, MaggiGroup® basic range of calibrated anchor chains will take on the quality-distinctive brand of AQUA 4.

AQUA 4 mechanical performance is 33% better and, more specifically, has 33% more tensile strength compared to a Grade 30 traditional chain. With some of the chains from east(read China fake chain)  being only G20’s the AQUA4 is twice as strong.

You can also see the AQUA7 is a massive 133% stronger than a Grade 30. The AQUA7 is the strongest short link anchor chain available which means you can swap a 10mm G30 to a 8mm AQUA7 and end up with a stronger chain. But remember you do lose weight.But you need Titanium Shackles.

 

I Use and Recommended for connecting chain – Anchor Shackles

By only renowned western manufacturers shackle standard  BS3032 – Bow Shackles  and EN 13889: 2003

Shackles – EN 13889: 2003  Standard and 

Predominantly used in the offshore, industrial and construction markets as a load rated lifting shackle, alloy steel shackles are also used in marine mooring applications. By far the most popular shackle types are the shackles with a screw pin, although safety pin versions are also available. Care needs to be taken when choosing shackles to this standard as there are many poor quality imitations currently in the EU -Usa market place. The faults can range from incorrect material used, lack of or incorrect heat treatment and poor manufacturing / machining processes leading to inferior quality.

Alloy Dee Shackle – Screw Pin – EN 13889: 2003 And Meets Performance Requirements Of U.S. Federal Specification RR-C-271

Material: Grade 6, quenched and tempered
Safety factor: 6 : 1
Test: Batch Tested and Certified
Finish: Hot Dip Galvanized

W.L.L.
(t)
D
(mm)
d
(mm)
 W
(mm)
 S
(mm)
E
(mm) 
Weight
each (Kg)
500 Kg7.0812.02216.50.05
750 Kg9.01013.52620.00.09
1.0010.01117.03222.50.14
1.5011.01319.03726.50.19
2.0013.51622.04334.00.32
3.2516.01927.05140.00.54
4.7519.02231.05946.00.87
6.5022.02536.07352.01.34
8.5025.02843.08559.02.08
9.5028.03247.09066.02.77

 

Alloy Bow Shackle – Screw Pin – EN 13889: 2003 And Meets Performance Requirements Of U.S. Federal Specification RR-C-271

Material: Grade 6, quenched and tempered
Safety factor: 6 : 1
Test: Batch Tested and Certified
Finish: Hot Dip Galvanized

 

W.L.L.
(t)
D
(mm)
d
(mm)
 W
(mm)
 S
(mm)
 R
(mm)
E
(mm) 
Weight
each (Kg)
500 Kg7.0812.029.02016.50.05
750 Kg9.01013.532.022200.10
1.0010.01117.036.52622.50.14
1.5011.01319.043.02926.50.19
2.0013.51622.051.032340.36
3.2516.01927.064.043400.63
4.7519.02231.076.051461.01
6.5022.02536.083.058521.50
8.5025.02843.095.068592.21
9.5028.03247.0108.075663.16

 

Alloy Dee Shackle – Safety Pin – EN 13889: 2003 And Meets Performance Requirements Of U.S. Federal Specification RR-C-271

Material: Grade 6, quenched and tempered
Safety factor: 6 : 1
Test: Batch Tested and Certified
Finish: Hot Dip Galvanized

 

W.L.L.
(t)
D
(mm)
d
(mm)
 W
(mm)
 S
(mm)
E
(mm) 
Weight
each (Kg)
2.0013.5162243340.39
3.2516.0192751400.67
4.7519.0223159461.08
6.5022.0253673521.66
8.5025.0284385592.46
9.5028.0324790663.40

Alloy Bow Shackle – Safety Pin – EN 13889: 2003 And Meets Performance Requirements Of U.S. Federal Specification RR-C-271

 

Material: Grade 6, quenched and tempered
Safety factor: 6 : 1
Test: Batch Tested and Certified
Finish: Hot Dip Galvanized

 

W.L.L.
(t)
D
(mm)
d
(mm)
 W
(mm)
 S
(mm)
 R
(mm)
E
(mm) 
Weight
each (Kg)
500 Kg7.0812.029.02016.50.06
750 Kg9.01013.532.02220.00.11
1.0010.01117.036.52622.50.16
1.5011.01319.043.02926.50.22
2.0013.51622.051.03234.00.42
3.2516.01927.064.04340.00.74
4.7519.02231.076.05146.01.18
6.5022.02536.083.05852.01.77
8.5025.02843.095.06859.02.58
9.5028.03247.0108.07566.03.66

 

BS3032 – Bow Shackles – Small

 

More and more port authorities require that lost anchors be removed from the sea bed, so these cases become “wreck removal” operations.

The weakest link
I looked at the technical reasons behind loss of anchors, and noted that anchors may be lost due to breakage of a common chain link, joining shackle, swivel, anchor shackle or bow shackle, and also through breakage of the anchor itself. One or both flukes may break and, surprisingly, also the solid anchor shank.

“A chain is only as strong as its weakest link” is an old saying, and when a part of the chain breaks it may be due to wear and corrosion or to over-stressing of that part. I think user require anchors and chain to be ranged every five years and that is the time to pay attention to every part of the chain. Second-hand chains Regalvanising and  offer in the market, but one should not buy them without a certificate of quality.. One should also be aware that chains and anchors have been offered with false class certificates. The low price may be one indicator.

 

Lost spile pins
The pin of the anchor shackle, which links the “fore-runner” to the crown shackle of the anchor, is sealed in the same way as for kenter shackles. There have been several cases where a chain in good condition comes up without the anchor and without the pin of the anchor shackle. The spile pin, securing the main pin of the shackle, seems to fall out relatively often.

Last week asked me friend of Goran large screwdriver because he can pull off fancy SWIVEL ANCHOR CONNECTOR 316 STAINLESS STEEL. I paddled to him with a bunch of screwdrivers, and really screw the front I could not pull off the combination screwdriver pliers. I try to unscrew the second screw, unscrew the ease by hand.

Breakage

If parts of an anchor break, there are good reasons to suspect defects of the cast metal, Some the anchor shank and anchor crown are made of cast steel, which requires a long heat treatment after casting. The manufacturers may have speeded up the production, cut time and temperatures needed for heat treatment, and that may not have been discovered by the authorities involved in testing and certification. If an anchor shank breaks, I recommends keep invoice and sending the remaining part to a test facility and comparing the results with the certificate. Do not buy anchor without certificate.