Mooring Tails and Connections
Tails or pennants will provide additional elasticity to wire and high modulus mooring lines and reduce the dynamic loads induced in the mooring line by allowing the ship to respond more freely to various combinations of wind, wave and current, as well as to ships passing nearby.
Tails will also distribute the loadings more evenly among the various mooring lines.
According to MEG4 the Tail Design Break Force (TDBF) should be 125%-130% of the ship design MBL.
Tails are generally connected to mooring lines either through the use of mechanical connecting devices (i.e. mooring links and mooring shackles with steel wire ropes) or directly with the use of a cow hitch (with HMPE ropes).
Single Leg Tail
- Standard 11m tails with 1m one end and 2m other end : adequate for sheltered pier side moorings where little or no wave induced vessel motions occur
- 22m tails : to be used at exposed pier side moorings where significant ship motions occur; will typically only be required for breast lines and may not be necessary for spring lines.
Grommet Type Tail
Grommet type tails are used in special applications requiring high strengths.
The eyes are formed by lashings (seizing the two rope bodies together to form an eye).
The strength of a Grommet mooring tail is 1.7 times the strength of a single leg (of the same material, construction and size) and its length depends on the customer’s requirements.
Tails can be attached directly to HMPE mooring lines using a cow hitch, whereby a pigtail (usually a small diameter conventional fibre rope) is recommended to help separate the tail and mooring line for replacement or inspection.
Using a cow hitch with a single leg tail does not significantly affect the strength efficiency of the mooring line assembly, while a grommet will result in a higher strength reduction and therefore, we do not recommend to use a cow hitch with a grommet tail.
Oversizing of tails to account for the potential loss of strength is not recommended due to the consequent effects on termination integrity and tail stiffness.
Mooring Link and Mooring Shackle
In the mooring system, a connection is needed to join the wire mooring line to the synthetic tail. The connection should be appropriate for the size and working load of the mooring wire.
TEHO Ropes offers class certified Magellan® and EuroRope mooring links and shackles.