Offshore Safety

Ramnäs Anchor Chainis a promiseFacts about Ramnäs Safety Anchor Chains and Accessories. 2006.

Ramnäs Quality Chains and Accessoriessince 1590 2009 and beyond

3

When hurricane winds reach 200-300 km/h, Mother Nature is not very kind. Everything that isn’t tough enough is torn out and hurled away by the speeding winds. Buildings and entire blocks turn into firewood, and cars, trains and boats are tossed around like toys. Oil rigs are ripped from their moorings, ships sink and millions of dollars are lost. The catastrophes just keep mounting. This is our everyday reality. It’s no place for compromises.

The oil rig’s lifelineThus far, Swedish offshore anchor chain from Ramnäs Bruk has with-stood the immense power of Mother Nature. To the best of our knowledge, not a single oil rig secured with Ram-näs chain has ever broken loose. The rig’s mooring is its insurance against hurricanes and the sands of time. Strength, durability and long ser-vice life are crucial. What it all comes down to is quality.

It begins in the steelworksSweden has a good reputation when it comes to steel and we have high-quality steelworks based on decades of experience. Ramnäs Bruk works very closely with them to develop the steel grades and alloys required by the tough reality of our customers. It was thanks to this close coopera-tion that back in 1999 we could pres-ent steel of Grade 4+ which in prin-ciple corresponds to today’s Grade 5.

Design and engineeringDurability depends on the design of the links and on the quality of the production technology used. At Ram-näs Bruk we have been making chains since the end of the 1800s. We know that Ramnäs chain fulfils its promise and this can be attested by both individual customers and inde-pendent surveys. All of which is highly gratifying. Ramnäs grade 4++ stud-link chain has no less than five times longer fa-tigue life than our standard chain, and 30% greater tensile strength.

Production and deliveryManufacturing chain of large dimen-sions is and will always be a heavy industrial procedure involving heavy and noisy mechanical processes. Qual-ity is the main concern at every stage of the manufacturing system. From loading of the steel blanks, bending, welding, hardening, fatigue testing, stud expansion, magnetic and UV checks to the finished, inspected and approved delivery. Every single link has its specific his-tory, its traceability and its manufac-turing and inspection data stored on file.

Talk to us about your ideasRamnäs Bruk is not just a renowned Swedish chain manufacturer. Our long experience has made us into a knowledge centre. We are happy to serve as your sounding-board during the design and engineering phase and while the calculations are being made. In addition to our standard products, we can help you produce customer-specific links in both short and long production series.

Offshore Safety is a promise

”Ramnäs Chains has better quality”

Fluke Engenharia Ltda. is a Brazil-ian-owned company whose main activities are structures fabrication and qualified tecnical services for the offshore industry, i. e. inspec-tion and tests of chains and acces-sories for mooring systems

Antonio Manuel is one of the directors at Fluke, in charge of in-spections and quality controls and have long experience in visual and mechanical tests of anchor chains and mooring systems.

Antonio Manuel, Fluke, Brazil.

”During our inspections we really have seen that Ramnäs has proved to have an excellent quality”, says Antonio.

Contents

Offshore Safety ..................................... 3Ramnäs High Strength Chains .......... 4-5Certification is not enough ............... 6-7Ramnäs stud chains ............................. 8Ramnäs studless chains ....................... 9Proof and brake loads .................. 10-11Mechanical properties ........................ 12Weight data......................................... 13Weight and volume data ..................... 14Elasticity of anchor data ..................... 15Weight of details ........................... 16-17Ramfor, Ramplate, Kenter ............. 18-21Truly heavy production ................. 22-23

4 5

Ramnäs Bruk develops high-strength grades and new link designs based on customer demands and new market standards. The general development of mooring chains has taken place in small steps from grade 2 (1948), grade 3 (1966), grade 4 (1982) to grade 5 (2006).

Ramnäs developmentIn 1999 Ramnäs presented the grade 4+ stud chain and three years later, the studless 4+. In 2002 grade 4++ was introduced in stud chains and in 2006 Ramnäs presented grade 5 stud and studless chains.

Customer demandsThe Borgland Dolphin was first to be equipped with NVR 4+ in 1999 due to specific demands from the customer, Statoil. The grade 4+ design and steel quality increased the proof and break load by more than 20 %. The follow-ing 4++ quality increased the proof and break load by 30 %.

Five times longer fatigue lifeTests show that Ramnäs grade 4+ has between five and eleven times the fa-tigue life of our standard grade 4 steel, see the figure.

Been in high grade since 1999With the development of grade 4+ and 4++ Ramnäs has been manufac-turing and supplying a steel quality that in many respects corresponds to and even exceeds the current grade 5 standard.

The benefits for the mooring system• Improvedfatiguelife,fivetimes

longer• Higherchainstrengthenhances

personnel and rig safety• Savesweightfortherig• Reducesinstallationcosts• Overalllinkdimensionallowsusage

of existing mooring equipment

Chains in the futureThere is constant development in the area of steel grades, design and pro-duction. Ramnäs looks to the future and carries out a wide variety of tests and trials. We have excellent contacts with the entire offshore industry and are quick to pick up on every change in the industry as it shifts its focus towards deep-water sources, for instance.

Production factsRamnäs manufactures and supplies chains from 70 – 165 mm (2.3/4” – 6.1/2”) in diameter. Ramnäs produces both stud-link chain and studless chain. We also design, manufacture and sell accessories and connectors. Since the end of the 1960s, the pro-duction process is linear, which allows us to deliver very long chains.

Ramnäs High Strength Chains

•Thelongestlengthofchainthathas ever been manufactured at Ramnäs measured 2.2 km (2007).•Theheaviestchainthathassofarbeen delivered weighed 385 tonnes. (2005).

Did you know that...

035

The diagram shows fatigue tests performed by the Royal Institute of Technology (KTH) in

Stockholm, Sweden. The curves shows much longer fatigue life for Ramnäs Grade 5 chains

compared to API RP2 SK R4 design curves, both for stud link and studless chain (76 mm

diameter).

Assymetric controlled stud expansion chains.

0.350

0.300

0.250

0.200

0.150

0.1001,0E+04 1,0E+05 1,0E+06 1,0E+07

Number of cycles to failure

Longer fatigue life

Load

Ran

ge/C

BS

johannes.nylund@eiab

API design curve API design curveRamnäs Grade 5 studless chain Ramnäs Grade 5 stud chain

6 7

Certification is not enough

From customer contact to deliveryFor our customers, quality and service are the most crucial criteria. We are keen to participate early in the process and are happy to provide estimates, calculations and expertise on material grades, designs and characteristics.

Hot Bend TestBefore we accept the steel in the pro-duction system, we carry out what is knownasa“HotBendTest”,whichis a highly demanding bending test whose aim is to optimise weld and seam integrity.

During the production process, which includes heat treatment and single or double hardening, several tests are carried out involving techniques such as ultrasonic inspection and magnetic particle examination to check for surface defects. Each and every link is subjected to a proof load test. Every measurement is logged, and the test history of every link can thus be moni-tored and traced back to source.

We like to be thoroughWe have cooperation with the cer-tification companies and we always meet the set requirements. But we go further. We want to be absolutely certain that we’ve done everything we possibly can to ensure you have the best possible chain.

Read more on the WebOn our Website, www.ramnas.com, you will find more information about our certification.

•Ramnäshasdeliveredmorethan300,000 tons of chain, in use today the world over.

Did you know that...

Quality is a lifestyle and committment and that takes the chains of Ramnäs Bruk offshore all over the world.

0.398

0.316

0.251

0.200

0.158

0.126

0.100104 105 106 107

Number of cycles to failure

Noble Denton mean curve Stud link chain Nov -94

API design curve

Load range/CBS-NVK4-Rig

Ramnäs Studless chain fatigue life compared to API design curve and Noble Denton mean curve for stud link chain

Manufacturing Record BookRamnäs provides you with the best and most proper documenta-tion including the Manufacturing Record Book with classification society certificate and records from production and testing.

Documentation

FE-analysis of stress distribution in a studless chain link.

8 9

Stud-link chainsThere are many reasons for choos-ing stud-link chains. By tradition, studless chains are used on permanent platforms and stud-link chains are em-ployed on rigs where the chain is often reeled in and out. Studless chains are lighter, but it is sometimes necessary to have more weight in order to give the platform the appropriate charac-teristics.

Stronger and longer-lasting There are other important reasons for choosing Ramnäs stud-link chains. The expanded stud link gives the chain other valuable characteristics. It withstands higher loads and does not deform. It distributes and reduces tension, which in turn reduces wear and fatigue. The result is longer lifetime.

Controlled expansion The big difference between Ramnäs stud-link chains and those made by other manufacturers is that we have developed a method whereby we fully control stud expansion, that is to say the stud’s attachment in the link. This results in sealed joints, minimum of corrosion, and the stud remains homo-geneous and serves as an active part of the tension distribution mechanism.

5-year warrantyWith over 40 years of experi-ence working in the offshore sector, Ramnäs has been producing chains since 1876 in Ram-näs, Sweden. We at Ramnäs believe on our excellent product quality and we have introduced 5 Year Quality War-ranty on all our chains and subject to Orgalime S 2000.

StudsRamnäs anchor chain is fitted with drop-forged studs. Ramnäs has de-veloped an asymmetrical stud which gives more equal stud indentation and contributes to more symmetric stress-distribution in the link.Combined with our controlled stud-expansion (after proof-loading) this will prolong the period before non-welded studs work loose. Asymmetric studs combined with controlled stud expansion have been the Ramnäs standard since spring 1991. The stud designs are approved by the classifica-tion societies.

.

Contour of asymetric stud.

Contour of normal stud

Contour of a asymmetric stud

Contour of a normal stud

Studless chain reduce the weight and inspection down timeRamnäs Bruk’s studless link can deliv-er the same performance as a stud link in terms of static strength while offer-ing a saving of some 9% in weight. For deepwater applications, there is a potential reduction in weight, and consequent cost saving.

Alternatively, the weight can be kept constant and fatigue strength corre-spondingly increased by opting for a larger diameter chain. This option also gives a greater margin of safety against the incidence of corrosion.Studless chain is easier to inspect and being a simpler structure, requires less inspection.

DesignOur standard studless chain has width of 3.35 x d and the length of the stud-less link is 6 x d which is exactly the same as for stud link chain. Static strengthRamnäs studless chain withstands the same break load as a stud-link chain with the same nominal diameter

Ramnäs Studless Chains

Troll B proved what we already knewAfter 12 years in operation, the Troll B platform off Norway’s coast was subjected to meticulous inspection of its moorings.Troll B uses stud-link chains from Ramnäs. Not a single stud had come loose on the chain. Not a single crack could be seen.That’s what we mean by quality and economy.

“Ramnäs manufactures and sup-plies the best chains in existence,” says Hans B Lie, Technical Man-ager, Marine Operations, Hydro in Norway, which owns Troll B.

Did you know that...

Ramnäs Stud Chains

Conversion Factors for SI-unitsThis table only provides conversion factors for US units and MKS units that differ from SI units. Proper use of significant figures and rounding-off techniques should be given due consid-eration when using conversion factors.

Quantity U.S. or MKK Unit Multiply by To obtain SI Units

Area ft2 9.290 304 (10-2)* m2

in.2 6.451 600 (10-2)* mm2

Energy, Work BTU 1.055 056 (103) Jft-lb 1.355 818 Jin.-lb 1.129 848 (10-1) Jkcal 4.186 800 (103)* Jkg-m 9.806 650* J

Force lbf 4.448 222 Nton (long) 9.964 017 (103) Nkgf 9.806 650* Nton (metric) 9.806 650 (103) NKIP = 1.000 lbf 4.448 222 kN

Length fathom 1.828 800* mft 3.048 (10-1)* min. 2.540 (101)* mm

Mass lb 4.535 924 (10-1) kgton (long) 1.016 047 (103) kgton (metric) 1.000 (103) kg

Pressure, Stress ksi 6.894 757 (106) N/m2 (or Pa)psi 6.894 757 (103) N/m2 (or Pa)

6.894 757 (10-3) N/m2 = MPa6.894 757 (10-2) bar (or 105 N/m2)

ton (long) / in.2 1,544 426 (107) N/m2 (or Pa)1,544 426 (107) N/mm2

kg/cm2 9.806 650 (104)* N/m2 (or Pa)bar (or 105 N/m2) 9.806 650 (10-7)kg/mm2 9.806 650 (106)* N/m (or Pa)

Temperature °F (°F-32) / 1.8 °C* exact value

10 11

Due to the application of different rounding-off-principles for calcula-tion of loads, individual classification societies show slightly different load values in their tables. Conversion factors, see page 9.

Proof and break loads (kN)

LOAD (in kN) = c x d2 x (44 – 0.08 x d) (d in mm)

Grade ORQ R3/NVR3

R3S R4 R4S R5 ORQ R3 NVR3 R3SStud

R3SStudless

R4Stud

R4Studless

R4S Stud

R4S Studless

R5 Stud

R5 Studless

C-factor 0,0211 0,0223 0,0249 0,0274 0,0304 0,032 0,014 0,0148 0,0156 0,018 0,0174 0,0216 0,0192 0,024 0,0213 0,0251 0,0223 Stud Studlessmm kg/m

70 3970 4196 4685 5156 5720 6021 2634 2785 2935 3387 3274 4064 3613 4516 4008 4723 4196 107 9873 4291 4535 5064 5572 6182 6507 2847 3010 3172 3660 3538 4392 3904 4881 4331 5104 4535 117 10776 4621 4884 5454 6001 6658 7009 3066 3242 3417 3942 3811 4731 4205 5257 4665 5498 4884 126 11678 4847 5123 5720 6295 6984 7351 3216 3400 3584 4135 3997 4962 4411 5514 4893 5766 5123 133 12281 5194 5490 6130 6745 7484 7877 3446 3643 3840 4431 4283 5317 4726 5908 5243 6179 5490 144 13184 5550 5866 6550 7208 7997 8418 3683 3893 4104 4735 4577 5682 5051 6313 5603 6602 5866 155 14187 5916 6252 6981 7682 8523 8971 3925 4149 4374 5046 4878 6056 5383 6729 5972 7037 6252 166 15190 6289 6647 7422 8167 9062 9539 4173 4412 4650 5365 5187 6439 5723 7154 6349 7482 6647 177 16292 6544 6916 7722 8497 9428 9924 4342 4590 4838 5582 5396 6699 5954 7443 6606 7784 6916 185 16995 6932 7326 8180 9001 9987 10512 4599 4862 5125 5913 5716 7096 6307 7884 6997 8246 7326 198 18197 7195 7604 8490 9343 10366 10911 4774 5047 5319 6138 5933 7365 6547 8184 7263 8559 7604 206 188100 7596 8028 8964 9864 10944 11520 5040 5328 5616 6480 6264 7776 6912 8640 7668 9036 8028 219 200102 7868 8315 9285 10217 11336 11932 5220 5519 5817 6712 6488 8054 7159 8949 7942 9359 8315 228 208105 8282 8753 9773 10754 11932 12560 5495 5809 6123 7065 6829 8478 7536 9420 8360 9851 8753 241 221107 8561 9048 10103 11118 12335 12984 5681 6005 6330 7304 7060 8764 7790 9738 8643 10184 9048 251 229111 9130 9650 10775 11856 13154 13847 6058 6404 6750 7789 7529 9347 8308 10385 9217 10861 9650 270 246114 9565 10109 11287 12420 13780 14506 6346 6709 7071 8159 7887 9791 8703 10879 9655 11378 10109 285 260117 10005 10574 11807 12993 14415 15174 6639 7018 7397 8535 8251 10242 9104 11380 10100 11902 10574 300 274120 10452 11047 12334 13573 15059 15852 6935 7331 7728 8916 8619 10700 9511 11889 10551 12434 11047 315 288122 10753 11365 12690 13964 15493 16308 7135 7542 7950 9173 8868 11008 9785 12231 10855 12792 11365 326 298124 11057 11686 13048 14358 15930 16768 7336 7755 8175 9432 9118 11319 10061 12576 11161 13153 11686 337 308127 11516 12171 13591 14955 16592 17466 7641 8078 8515 9824 9497 11789 10479 13099 11626 13700 12171 353 323130 11981 12663 14139 15559 17262 18171 7950 8404 8858 10221 9880 12265 10903 13628 12095 14253 12663 370 338132 12294 12993 14508 15965 17713 18645 8157 8623 9089 10488 10138 12585 11187 13984 12411 14625 12993 382 348137 13085 13829 15441 16992 18852 19844 8682 9178 9674 11162 10790 13395 11906 14883 13209 15565 13829 411 375142 13887 14677 16388 18033 20008 21061 9214 9741 10267 11847 11452 14216 12637 15796 14019 16520 14677 442 403147 14700 15536 17347 19089 21179 22294 9753 10311 10868 12540 12122 15048 13376 16720 14839 17487 15536 473 432152 15522 16405 18317 20156 22363 23540 10299 10887 11476 13241 12800 15890 14124 17655 15669 18464 16405 506 462157 16352 17282 19297 21234 23559 24799 10850 11469 12089 13949 13484 16739 14879 18599 16507 19452 17282 540 493162 17188 18166 20284 22320 24764 26068 11405 12056 12708 14663 14174 17596 15641 19551 17351 20447 18166 575 525167 18030 19056 21278 23414 25977 27345 11963 12647 13330 15381 14869 18458 16407 20508 18201 21448 19056 611 558172 18876 19950 22276 24513 27196 28628 12525 13240 13956 16103 15566 19324 17177 21471 19055 22455 19950 648 592177 19725 20847 23278 25615 28420 29915 13088 13836 14584 16827 16267 20193 17949 22437 19912 23465 20847 686 627

Grade ORQ R3/NVR3

R3S R4 R4S R5 ORQ R3 NVR3 R3SStud

R3SStudless

R4Stud

R4Studless

R4SStud

R4SStudless

R5Stud

R5Studless

C-factor 3060,3 3234,3 3611,4 3974,0 4409,1 4641,2 2030,5 2147,0 2262,6 2610,7 2523,7 3132,8 2784,7 3480,9 3089,3 3640,4 3234,3 Stud Studlessinch lb/ft

2 3/4 889 940 1049 1154 1281 1348 590 624 657 758 733 910 809 1011 897 1058 940 72 662 13/16 927 979 1094 1203 1335 1406 615 650 685 791 764 949 843 1054 936 1102 979 75 692 7/8 965 1020 1139 1253 1391 1464 640 677 714 823 796 988 878 1098 974 1148 1020 78 722 15/16 1004 1061 1185 1304 1447 1523 666 705 743 857 828 1028 914 1142 1014 1195 1061 82 753 1044 1103 1232 1356 1504 1583 693 732 772 891 861 1069 950 1187 1054 1242 1103 85 783 1/16 1084 1146 1280 1408 1562 1644 719 761 802 925 894 1110 987 1233 1095 1290 1146 89 813 1/8 1125 1189 1328 1461 1621 1706 747 789 832 960 928 1152 1024 1280 1136 1338 1189 93 853 3/16 1167 1233 1377 1515 1681 1769 774 819 863 995 962 1194 1062 1327 1178 1388 1233 96 883 1/4 1209 1278 1426 1570 1742 1833 802 848 894 1031 997 1237 1100 1375 1220 1438 1278 100 923 5/16 1251 1323 1477 1625 1803 1898 830 878 925 1068 1032 1281 1139 1423 1263 1489 1323 104 953 3/8 1295 1368 1528 1681 1865 1964 859 908 957 1105 1068 1325 1178 1473 1307 1540 1368 108 993 7/16 1339 1415 1580 1738 1928 2030 888 939 990 1142 1104 1370 1218 1522 1351 1592 1415 112 1023 1/2 1383 1462 1632 1796 1992 2097 918 970 1022 1180 1140 1416 1258 1573 1396 1645 1462 116 1063 9/16 1428 1509 1685 1854 2057 2165 947 1002 1056 1218 1177 1462 1299 1624 1441 1698 1509 120 1103 5/8 1473 1557 1739 1913 2123 2234 977 1034 1089 1257 1215 1508 1341 1676 1487 1752 1557 125 1143 3/4 1566 1655 1848 2033 2256 2374 1039 1098 1158 1336 1291 1603 1425 1781 1580 1862 1655 134 1223 7/8 1660 1754 1959 2156 2392 2518 1101 1165 1227 1416 1369 1699 1511 1888 1676 1975 1754 143 1303 15/16 1708 1805 2016 2218 2461 2590 1133 1198 1263 1457 1409 1748 1554 1943 1724 2032 1805 147 1344 1756 1856 2073 2281 2531 2664 1165 1232 1299 1498 1448 1798 1598 1998 1773 2089 1856 152 1394 1/8 1855 1960 2189 2408 2672 2813 1231 1301 1371 1582 1530 1899 1688 2110 1872 2206 1960 162 1484 1/4 1955 2066 2307 2538 2816 2965 1297 1371 1445 1668 1612 2001 1779 2223 1973 2325 2066 171 1574 3/8 2057 2174 2427 2671 2963 3119 1365 1443 1521 1754 1696 2105 1871 2339 2076 2446 2174 182 1664 1/2 2160 2283 2549 2805 3112 3276 1433 1515 1597 1843 1781 2211 1966 2457 2181 2570 2283 192 1764 5/8 2265 2394 2673 2941 3263 3435 1503 1589 1675 1932 1868 2319 2061 2576 2287 2694 2394 203 1854 3/4 2372 2507 2799 3080 3417 3597 1574 1664 1753 2023 1956 2428 2158 2698 2394 2821 2507 214 1964 7/8 2480 2621 2926 3220 3573 3761 1645 1740 1833 2115 2045 2538 2256 2820 2503 2950 2621 226 2065 2589 2736 3055 3362 3730 3926 1718 1816 1914 2209 2135 2650 2356 2945 2614 3080 2736 237 2175 1/8 2700 2853 3186 3506 3890 4094 1791 1894 1996 2303 2226 2764 2457 3071 2725 3211 2853 249 2285 1/4 2812 2971 3318 3651 4051 4264 1865 1972 2079 2398 2319 2878 2558 3198 2838 3344 2971 262 2395 3/8 2925 3091 3451 3798 4214 4435 1940 2052 2162 2495 2412 2994 2661 3327 2952 3479 3091 274 2505 1/2 3039 3211 3586 3946 4378 4608 2016 2132 2247 2592 2506 3111 2765 3456 3067 3615 3211 287 2625 5/8 3154 3333 3722 4095 4544 4783 2093 2213 2332 2690 2601 3228 2870 3587 3184 3752 3333 300 2745 3/4 3270 3456 3859 4246 4711 4959 2169 2294 2417 2789 2696 3347 2975 3719 3301 3890 3456 314 2875 7/8 3387 3579 3997 4398 4879 5136 2247 2376 2504 2889 2793 3467 3082 3852 3419 4029 3579 328 2996 3504 3704 4135 4551 5049 5315 2325 2459 2591 2989 2890 3587 3189 3986 3538 4169 3704 342 3126 1/8 3623 3829 4275 4704 5219 5494 2404 2542 2678 3090 2987 3709 3296 4121 3657 4309 3829 356 3256 1/4 3742 3954 4416 4859 5391 5675 2483 2625 2766 3192 3086 3830 3405 4256 3777 4451 3954 371 3396 3/8 3861 4081 4557 5014 5563 5856 2562 2709 2855 3294 3184 3953 3514 4392 3898 4593 4081 386 3526 9/16 4042 4271 4769 5248 5823 6129 2682 2835 2988 3448 3333 4137 3678 4597 4080 4808 4271 409 3736 3/4 4223 4463 4983 5483 6084 6404 2802 2962 3122 3602 3482 4323 3842 4803 4263 5023 4463 433 3957 4465 4719 5269 5798 6433 6772 2963 3133 3301 3809 3682 4571 4063 5079 4507 5311 4719 465 425

TestLoad

Break Load Proof Load WeightTestLoad

Break Load Proof Load Weight

LOAD (in KIP) = c x d2 x (44 – 2.032 x d)/1000 (d in inch)

Proof and break loads (KIP)

12 13

Mechanical Properties

Twist of stud link anchor chainA twist of 45 degrees over 5 links is acceptable without noticeable decrease of chain strength. More twist under load will deform the chain. Thus a 90-foot length of chain may be twisted under load according to the formula:

ϑmax = =

Where D is chain nominal diameter in mm.

27500 x 454 x D x 5

61875D

Coefficient of friction for anchor chainThe coefficient of friction depends upon the actual ocean bottom at the anchor location. General friction fac-tors for chains are given in the table. The starting friction factors may be used to compute the holding power of the chain. The sliding friction factor may be used to compute forces on the chain during deployment.

Submerged weight of chainThe submerged weight of chain varies with the density of the seawater, but can be roughly estimated using this formula.

Submerged weight = x weight of chain in air = 0,87 x weight of chain in air

v1 = Density of steel = 7,85 kg/dm3 v2 = Density of seawater ≈ 1,02 kg/dm3

(v1 – v2)v1

[ ]

Weight data

Classification Society API Spec 2F

Ramnäs Inhouse

Offshore Mooring Chain (IACS W22) DNV-OS-E302October 2008

Quality ORQ ORQ+20% R3 R3S R4 R4S R5Tensile testYield strength Re (N/mm2) - - 410 490 580 700 760Ultimate tensile strength Rm (N/mm2) 641 750 690 770 860 960 1000Elongation A5 (%) 17 15 17 15 12 12 12Reduction of area Z (%) 40 40 2) 50 2) 50 3) 50 3) 50 3) 50Impact strengthMin average energy, parent material (J) 58 40 58 60 40 65 45 50 56 58Min average energy, weld (J) 49 36 34 50 30 53 33 36 40 42Test temperature 1) °C 0 -15 0 0 -20 0 -20 -20 -20 -20

1) At the option of the Society the impact test of grade R3 and R3S may be carried out at 0°C or -20°C.2) For cast accessories, the minimum value shall be 40%.3) For cast accessories, the minimum value shall be 35%.

Ocean bottom Friction factorsStarting Sliding

Sand 0.98 0.74Mud with sand 0.92 0.69Firm mud 1.01 0.62Soft mud 0.90 0.56Clay 1.25 0.81

Chain holding power generalized friction factors for mooring chain.

Chain dimension mm Allowable maximum twist of 90-foot lengthϑ degrees No. of turns of 360°

57 1086 368 910 2,585 728 2114 543 1,5172 360 1

800

700

600

500

400

300

200

100

070 85

Weight Stud link chain

Weight Studless chain

Weight (kg/m)

100 115 130 145 160 175 Diameter mm

2 3/4 3 1/4 4 1/4 4 3/4 5 1/4 5 3/4 6 1/4 6 3/43 3/4 Diameter inch

500

450

400

350

300

250

200

150

100

50

0

Weight (lb/ft)

14 15

Weight and volume data Elasticy data of stud link chain

Weight

Space reguirementin locker

Volume (deplacement)

80.000

75.000

70.000

65.000

60.000

55.000

50.000

45.000

40.000

35.000

30.000

25.000

20.000

15.000

10.000

5.000

0

30

25

20

15

10

5

0

kg

20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 mmDiameter of chain

20.000

10.000

5.000

0

7" 177 mm

6" 152 mm

5" 127 mm

4" 102 mm

3" 76 mm

2" 51 mm

PKN

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 % ξ

The modulus of elasticity for anchor chain (E) is expressed by the equation:

Where:E is Youngs modulus expressed in MPAP is the load that causes a ductile elongation (strain) of ξ, P is expressed in Newton.d is the chain diameter (wire dia) expressed in mm.ξ is the strain expressed in %.π is 3,14.

E = = 640002 x P x 100d2 x ξ x π

Weight = 2,19 x 102 x D2 kg/mVolume = 1,095 x 10-5 x D2 m3/mD. nominal chain diameter in mm.

m3Appr

oxim

ate

wei

ght p

er 1

00 m

of c

hain

Appr

oxim

ate

volu

me

per 1

00 m

of c

hain

17

Approximate weight of detailsRamfor/KenterShackle

JoniningShackle

JoiningShackle

AnchorShackle

AnchorShackle

CommonStud

CommonStudless

EnlargedLink

EndLink

Diameter Type D LTM LTM Link Linkmm kg kg kg kg kg kg kg kg kg

70 45 75 - 110 - 30 25 40 4573 50 85 - 125 - 35 30 45 5076 60 100 110 140 155 40 35 50 6078 65 105 115 150 165 42 38 55 6581 75 120 130 170 185 45 45 60 7084 85 135 145 195 210 50 45 70 8087 95 150 165 220 240 60 55 75 8590 105 165 185 245 265 65 60 80 9592 105 175 191 255 280 70 60 90 10095 115 200 220 290 315 75 70 100 11097 135 210 230 305 330 80 75 100 120100 150 230 250 335 365 90 80 110 130102 150 245 265 350 380 95 85 120 140107 175 285 310 410 445 110 100 140 160111 200 305 335 445 485 120 110 160 175114 225 325 360 475 520 130 120 175 195117 225 345 385 505 555 140 130 185 210122 265 380 420 550 600 160 145 210 235127 315 420 465 600 660 180 165 235 260132 370 480 530 675 740 205 185 260 305137 390 550 605 750 825 230 205 285 330142 450 650 710 900 985 255 230 325 375147 505 720 790 1055 1145 280 255 395 410152 545 845 885 1200 1300 310 280 410 460157 610 932 975 1550 1655 345 310 455 510162 665 1025 1070 1700 1820 380 340 500 560167 725 1125 1175 1970 2100 415 375 540 630172 790 1225 1285 2300 2440 450 405 590 680177 865 1340 1400 2700 2855 490 445 640 730

Ramfor/KenterShackle

Joining Shackle

Joining Shackle

AnchorShackle

AnchorShackle

CommonStud

CommonStudless

EnlargedLink

EndLink

Diameter Type D LTM LTM Link Linkinch lbs lbs lbs lbs lbs lbs lbs lbs lbs2 3/4 95 165 240 65 60 90 1002 7/8 110 190 275 75 70 100 1153 130 220 245 310 340 90 75 110 1303 1/16 145 235 260 330 365 95 85 120 1403 3/16 165 260 290 375 410 100 95 135 1553 5/16 185 295 325 425 465 115 105 150 1703 7/16 205 330 365 480 525 125 115 165 1903 9/16 230 370 405 535 580 140 130 180 2103 5/8 230 385 420 565 615 150 135 195 2203 3/4 255 440 485 640 695 165 150 215 2453 7/8 300 465 510 670 730 175 160 225 2653 15/16 330 505 555 740 800 195 175 245 2854 330 535 585 770 840 205 185 365 3054 1/4 385 630 685 905 985 240 215 310 3504 3/8 440 670 745 980 1070 265 240 350 3854 1/2 495 715 790 1045 1150 285 260 380 4254 5/8 495 760 745 1115 1220 315 280 405 4654 3/4 588 840 930 1210 1325 350 320 465 5205 695 925 1025 1325 1455 400 360 520 5755 1/8 815 1060 1170 1490 1630 450 405 575 6705 3/8 860 1215 1340 1655 1815 505 455 630 7255 5/8 990 1435 1565 1985 2165 560 505 715 8255 3/4 1115 1590 1740 2325 2525 615 560 870 9056 1200 1785 1950 2645 2870 685 620 905 10156 3/16 1350 2140 2320 3420 3650 760 685 1005 11256 3/8 1460 2350 2540 3750 4010 835 750 1100 12356 9/16 1600 2620 2845 4340 4630 910 820 1190 13906 3/4 1740 2930 3165 5070 5385 995 900 1300 15007 1900 3220 3475 5950 6295 1085 980 1415 1610

a Common Stud Link a Common Studless Link b Enlarged Link c End Link

d Joining shackle type D Joining shackle with round pin, LTM design3,4 D

6 D

3,6

D

D

4 D 4,4 D 4,35 D

6 D 6,6 D 6,75 D

3,35

D

4 D

4 D

1,1

D

1,2

DD

1,6 D 0,8 D

7,1 D

4 D

1,4

D

1,3

D

2,8

D1,

2 D

3,4 D

7,1 D

0,8 D

4 D

1,4

D3,

2 D

2,2 D

D = diameter of chain

f Anchor shackle type D Anchor shackle type D LTM design Special anchor shackle* with round pin, LTM design

4 D

8,2 D

1,9 D0,9 D

5 D

2,2

D

1,4

D 3 D

1,3

D

4 D1,9 D

8,2 D

5 D

2,2

D0,

55 D 4,1 D

8,175 D1,775 D

Ø1,8 D

0,55

D5

D

2,2

D

1,4

D 3 D

1,3

D

2,5 D

1,4

D 3,4

D

0,15 D

2,3 D

Joining shackle type D LTM design3,4 D 1,6 D 0,8 D

0,5

D4

D1,

4 D

1,2

D2,

8 D

2,2 D

Ø1,6D

1,3

D D = diameter of chain* Connected only with special end link

7,1 D

Approximate weight of details

18 19

Ramfor connectorsThe Ramfor connector has the same outside shape as the traditional Kenter joining shackle but with improved fa-tigue properties. The difference is the design of the interior. The Ramfor and Ramfor Slim designs have a locking head of a different design than that of the Kenter joining shackles. This lock-ing head has been designed to provide a large load-carrying area which in turn gives a better stress distribution. The Ramfor Slim connector has the same outside shape as the Kenter joining shackle and Ramfor connector but with an outside thickness (D) of 1.30 x d. This thickness is equal to the Baldt type connector, but slimmer than the Kenter joining shackle and the Ramfor (1.52 x d). The slim shape enables the Ramfor Slim connector to be used on every mooring system on semi-submersibles, offshore loading systems and so on, and will fit any wildcat.

Sizes: Ramfor and Ramfor Slim are available for 70, 76, 84, 90, 95, 102, 108, 114, 120 and 127 mm diameter anchor chains. Grades: Ramfor and Ramfor Slim are available in all grades. Connectors Ramfor and Ramfor Slim for 76 and 84 mm diameter in grade R4 are available from stock.

Anchor shacklesAnchor shackle type Ramfor is based on the same interior design principles incorporated in the Ramfor/Ramfor Slim connectors with the locking head designed to provide a larger load-car-rying area which in turn gives better stress distribution. The Kenter Anchor shackle has the same outside shape as a Ramfor anchor shackle and with a simplified interior equivalent to a Kenter.Both shackles are our closest equiva-lents to the Baldt (pear-shaped) detachable anchor connecting link. The small end of the shackle is designed to accept a common link for the sizes mentioned below. This eliminates costly enlarged links and end links. The Ramfor Anchor shackle and Kenter Anchor shackle are dismantled / assembled in a similar way to the Kenter and Ramfor connectors.

Sizes: Ramfor Anchor shackles are available for 70, 76, 84, 90, 95 and 120 mm diameter anchor chains. Grades: Ramfor Anchor shackles are available in offshore grades R3, R3S and R4.

RamplateThe new Ramplate is a connector between anchor chains and wire segments. It eliminates the need for Tri-plate and joining shackles. Ramplate is cost-saving and offers the option of making length adjust-ments of the chain, since no end link is needed.

Sizes: Ramplate is available for 70-165 mm diameter anchor chains. Grades: Ramplate is available in all grades.

Ramfor improved moorings Dimensions for Ramfor and Kenter anchor shackles

CommonLink Ø

A B C D E F G H I J K L M

70 mm 370 538 368 99 70 100 103 105 113 46 80 145 12276 mm 405 588 402 108 78 109 112 116 123 51 89 160 13384 mm 440 640 437 118 85 118 122 126 134 55 96 174 14590 mm 440 723 494 132 96 134 138 143 152 62 109 196 16495 mm 497 723 494 132 96 134 138 143 152 62 109 196 164120 mm 578 824 570 154 120 169 175 180 176 78 125 226 207

RAMFOR™ Anchor ShackleBC

M

K

JA

F

H

L

Taper pinSuitable for common link

KENTER Anchor Shackle

BC

M

JA

F K

H

L

Taper pinSuitable for common link

G GI I

Ø E Ø D Ø E Ø D

20 21

Chain fatigue versus connector and D-shackle fatigue

XX X

XXX

X

Test no. Type of shackle Mean load level (kN)

Max load level (kN)

Cycles to failure

R1 Ramfor™ 210 2100 41700R2 Ramfor™ 260 2600 19200R3 Ramfor™ 260 2600 25000R4 Ramfor™ 260 2600 18400K1 Kenter 210 2100 35500K2 Kenter 260 2600 13000K3 Kenter 260 2600 14700K4 Kenter 260 2600 16900

Results from full-scale fatigue tests (in air) by Swedish National Testing and Research Institute. The “cycles to failure” column illustrates the Ramfor fatigue test results compared with Kenter joining shackles for 76 mm diameter grade R4.

Dimensions for Ramfor and Kenter connectors

Dimension designation

RAMFOR nomi-nal dimension times d.

RAMFOR Slim nominal dimen-sion times d.

Kenter nominal dimension times d.

Tolerance %

– +

A 6.00 6.00 6.00 2.0 2.0B 4.20 4.20 4.20 2.0 2.0C 1.83 1.83 1.83 2.5 2.5E 0.67 0.67 0.67 0.0 2.5R 4.50 4.50 4.50 2.5 2.0K 1.40 1.40 1.40 2.5 2.5S 1.00 0.82 1.10 2.5 2.5M 1.41 1.41 1.45 2.5 2.5N 1.28 1.32 1.32 2.5 2.5W 1.34 1.22 1.34 2.5 2.5F 1.13 1.13 1.13 0.0 2.5T 1.59 1.59 1.59 2.5 2.0U 1.30 1.30 1.30 2.5 2.0D 1.52 1.30 1.52 2.5 2.0d 1.00 1.00 1.00 0.0 5.0r 0.03 0.03 0.03 0.0 2.0

0.398

0.316

0.251

0.200

0.158

0.126

0.100

API design curve

Noble Denton mean curve Stud link chain. Nov -94

104 105 106 107

XRAMFOR KENTER D-Shackle

Number of cycles to failure

Load range/CBSRAMFOR

B

RAMFOR SLIM KENTER

B B

R R R

A A A

C C C

K KK

E E E

F F FN N

N

r

SS

M MM

r r r r r

W W W

S S SU U U

ddd

DDD

T T T

22

Truly heavy production

For decades now, Ramnäs has been at the forefront of new technology and new material grades. We undertake extremely close cooperation with the entire offshore industry and many of our solutions have been developed together with our customers. All for one single purpose - to provide the market’sbestchain.Herearesomeofthe major factors behind our success:

• 1990RamforandRamforSlimareintroduced on the market and approved by ABS, DnV and LRS.• 1991Ramnäsintroducesasymmetricalstuds and controlled stud expansion. They are approved by ABS, DnV and LRS.• 1992Thebiggestdimensionsforgrade4 ever, 160 and 157 mm diameter, are approved by ABS, DnV and LRS. In the same year, Ramfors anchor shackle de-sign is approved.

• 1994DnVapprovesRamnässtudlesschains. ABS and LRS issue approval In 1995.• 1995Worldrecordforstudchainofgrade 4, 152 mm (6”) diameter NVK4-RIG for Norsk Hydro, Troll B.• 1996Worldrecordagain.Studlesschain, diameter 6 1/4”, R3S for S.B.M./BP Schiehallion.• 1999Thenewgrade4+islaunchedand approved.• 2001RaceQProductionReportingSystem introduced.• 2000Newautomaticmagneticparticleinspection system installed.• 2006RamnäscertifiedaccordingtoOHSAS 18001 (Occupational Health and Safety Management System) by DNV.• 2006Newhigh-temperaturegrinderandexpansion with an additional forge in the production facility• 2006Grade5introduced

Supplying a couple of kilometres of chain is a project in its own rightIt’s one thing to manufacture the chain. It’s quite another to transport it to an installation site at the other end of the world. We may be talking about kilometre-long chains of massive dimensions. Detailed logistics and meticulous methodology are required for trans-port and repackaging before the product gets to its destination.

Ramnäs delivers its products via train and ship all over the world, even though we are not located on the coast.

The production flow

Arrival control Cutting bars Forming of links Welding of links

Trimming of the links Shaping of the links Hot Bend Test IPre Heat Treatment Inspections

Heat Treatment Tensile and Impact Testing Proof Loading and Gauging Shotblasting

Magnetic Particle Inspection Ultra Sonic Inspection Dispatch Final Documentation

Breakload testing of full size link.Hold Point.

Offshore drilling and production involve taking great risks concering both human lives and equipment.In todays changing environment it is of great value to make an economic investment in and for future lives. Safe mooring arrangment is a must.Thestatementthatsuccessfuloffshoredrillingandproductionwouldbe impossible without reliable mooring is a claim that is neither new nor bold. Considerable values in the form of human live and equipment are at stake. Here, the quality of the mooring system is an important safety feature. Secondly, it is essential to operations,Inthissense,safemooringisanimportantfinancialconsideration.Thuswefindthatmooringcanbeviewedbothwithamindtoeconomyand as a matter of safety with future in mind.

Ramnäs Bruk AB P. O. Box 14, SE-730 60 Ramnäs Sweden. Phone: +46 220-220 00, Fax: +46 220-358 37. info@ramnas.com / www.ramnas.com

Ramnäs Sweden

Eklu

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Com

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AB S

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Offshore Safetysince 1590

with a mission for

a sustainable future

Ramnäs

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