OCIMF_Mooring_Equipment_Guidelines_(Second_Edition)

Appendix A

Design Standard jor

Tanker Mounted SPM Fittings

TIle recommendations apply to the number of mooring connections used, tile safe working loads oj

fillings, the dimellsion of chafe chains and attendant fitlings and the type and location of seCllrillg

devices and fairleads on board. The recommendations only deal with those features thal are necessary

to en.. lire th e correct m atching of equipment used for lI100ring aJ SPMs.

A.1 BOW CHAIN STOPPERS

Ships likely to trade to SPMs should be equipped with bow chain stoppers designed £0 accept 76 mm

chafe chain in accordance with the following table:

Ship Size Number of S. W.L. S.W.L.

Bow Stoppers (tonnes) (kN)

150.000 tonnes DWT or less

(approx. 175.000 d ispl1.)^1 200 1961

Over 150.000 but not greater

than 350,000 lonnes OWT

(approx. 175,000- 400,000^2 200 1961

displt·l

Over 350,000 tonnes owr

(approx. 400,000 displl.l^2 250 2452

Notes:

a) "Tonnes DWT" refers to the deadweight at maximum summer draft.

b) The safety factor on yield of bow stoppers should be 1.50 SWL. The test load should be equi.

valent to the SWL.

c) The recommendations above are based strictly on ship size as being tbe onJy general criteria that

can be used. Althongh terminal operalOrs may increase the SWL of Ihe chafe chain a nd equip·

ment to take accOunt of local environmeotal conditions, it is essential thal tbe dimensions of

the material remain as detailed in Section 5 of Reference 1, in order that it matches the onboard

equipment.

In practice. bow chain sioppers have been foun d to be safe and easy to use and maintain. The

bolV chain swppcr should be designed to -·ec urc standard 76 mm diameter slUd-link chain when

t.he chain engaging pawl or bar is in the closed position. The chain stopper should be designed

to freely pass a standard 76 mm diameter stud·link chain and ass ociated fittings when th e chain

engaging pawl. or bar is in the open posit.ion (See Figures A I and A2).