Anchor Chain Snubbing Guide

Chain Snubbers are essential for taking the strain off your windlass and providing additional shock load absorption.

There are multiple options for snubbing solutions - stainless steel chain hooks, grippers and grabs with or without a nylon tail or twin tails (V bridle) – select 3 Strand for single strops or Anchorplait for bridles.

Single line strops can be used over the bow roller, twin strop lines (V shaped bridles) are ideal for use with handed deck fairleads and mooring cleats.


Deployment:

Once the desired length of chain has been paid out, secure the end of the strop to a cleat and attach the hook/gripper/grab to the chain with slack in the line.

Ease off enough chain so that the strop is taking the load and remember to allow for the rope to stretch.

Rope Fibre Selection:

LIROS Nylon will stretch approximately 20% at the breaking point. There is no material difference in elasticity between 3 strand and Anchorplait construction. The aim is for the strop to take the strain.

The chain should be secured to a cleat or post if practicable or by means of a stopper, safety rope just in case the strop fails. The windlass should only be the strongpoint of last resort.

Choose a strop diameter roughly equal to your bower anchor warp size.

Bear in mind that an oversize nylon strop will not stretch as much as the correct size.

A slightly undersized nylon line will provide more shock absorption but may ultimately prove sacrificial.

Factor in: 

  • the type of anchoring
  • the length of time at anchor
  • whether the yacht is unattended.


Selecting your Chain Snubbing attachment: Hook, Grab or Gripper (Shackle)

Chain Hooks and Grabs are designed to achieve a simple but strong means of securing a line to a length of chain under load.

The internal dimensions of each link in a modern calibrated anchor chain are not large enough to facilitate a strong through-connection.

Chain hooks and grabs are therefore designed to fit over a link in one plane and rest on the next link which will naturally be at right angles.

The link on which the hook or grab rests therefore takes the load.

Hooks and Grabs can be divided into two broad categories:

  • Retentive - featuring a mechanism for remaining attached when the line is slack.
  • Plain - no retention mechanism but simpler, less fiddly to attach and detach.

There are other options for securing the snubbing line to the chain:

  • Fasten the line to the chain with a rolling hitch. An extra half hitch or two is advisable for extra security. A rolling hitch should present no problems when it comes to release, even after extended exposure to heavy loads, providing it is tied correctly. N.B knots have a detrimental effect on rope strength: Strength loss through tying knots
  • Make up a suitably strong, spliced endless loop i.e. a Prusik Cord from e.g. 100% dyneema SK75, 78 or 99 braided line and connect it to the chain by means of a Prusik Hitch

Bear in mind that the attachment and detachment of the snubbing line to the chain by whatever means you select may mean stooping or kneeling and leaning out over the bow roller

 

Choosing between a Single Strop and a Twin Tail V Bridle:


Chain Snubbing Strop

Single line snubbing strops address the issue of snatch loading associated with all chain anchor rode systems in the shape of a single stretchy nylon line which takes the strain of the rode. The snubbing line can be led offset through a port or starboard fairlead but for longer term anchoring it should pass over the bow roller, through the stem head fitting and attach to the most suitably positioned strongpoint. This will require a careful, precautionary appraisal of any potential wear points and preventive action where necessary: Anti-Chafe Options

Single Line Snubbing, important features and information:

  • A Jimmy Green snubbing line should be approximately 3 metres to 10 metres in length - the longer it is, the more it will stretch.
  • The strop is attached to the chain with a rolling hitch or a spliced chain hook/Grab which can be retentive, the other end is made off to a strongpoint on the foredeck
  • The strength (diameter) of the strop should be comparable with your main anchor rode
  • Splicing retains far more of the rope strength than tying a knot - knots can reduce the break load by as much as 40% while a professional splice will generally retain approximately 80-85% of the original load capacity - both these percentages vary with the rope fibre, rope construction, type of knot and the splice construction.
  • Adding a mooring compensator will increase the elasticity of the strop - this extra shock absorbing capacity could be utilised to reduce the length of the line.
  • Adding anti-chafe webbing will protect the line where it leads over the bow roller, through the stem fitting and where it may come into any abrasive contact from there to the strongpoint.

 

V shaped Anchor Chain Snubbing Bridles

Twin tail snubbing bridles provide an excellent shock absorbing solution where the forward deck layout or the stem head and bow roller design/dimensions are not conducive to the successful arrangement of a single snubbing line

V Shaped Twin Tail Snubbing, important features and information:

  • A Jimmy Green V shaped bridle is based on the Anchorplait centre eye splice (with or without a thimble/chain hook).
  • The bridle consists of a continuous line, made into a soft loop around the eye of a fitting or formed around a hard thimble eye with a brummel locking tuck splice.
  • The strength of the bridle is therefore not reliant on a Y Joining Splice i.e. splicing two separate ropes together.
  • The maximum angle of deployment must always be set up with caution but the centre eye splice is much less prone to failure at a wider than optimum angle than any joining splice between two separate ropes.
  • It is not possible to successfully put a centre eye splice in a rope of 3 strand construction.
  • The strength (diameter) of the strop should be comparable with your main anchor rode.
  • Splicing retains far more of the rope strength than tying a knot - knots can reduce the break load by as much as 50% while a professional splice will generally retain approximately 80-85% of the original load capacity (this percentage does vary with the rope and splice construction).
  • Each tail (leg) of a Jimmy Green snubbing bridle should be approximately 3 metres to 10 metres in length - the longer it is, the more it will stretch
  • Adding a mooring compensator will increase the elasticity of the strop - this extra shock absorbing capacity could be utilised to reduce the length of the line.
  • Adding anti-chafe webbing will protect the line where it leads over the bow roller, through the stem fitting and where it may come into any abrasive contact from there to the strongpoint.

Selecting the correct Rope Construction for anchor snubbing:

Select 3 strand Nylon or Anchorplait Nylon for Single line Strops

Anchorplait Nylon (Octoplait 8 strand construction) is the only rope option to consider for making a V shape Bridle:

Jimmy Green V Shaped Anchorplait Bridle Splicing Plus Factors:

  • A Jimmy Green V shaped bridle is based on the Anchorplait centre eye splice (with or without a thimble/chain hook).
  • The bridle consists of a continuous line, made into a soft loop around a fitting or formed around a hard thimble eye with a brummel locking tuck splice.
  • The strength of the bridle is therefore not reliant on a Y Joining Splice i.e. splicing two separate ropes together.
  • The maximum angle of deployment must always be set up with caution but the centre eye splice is much less prone to failure at a wider than optimum angle than any joining splice between two separate ropes.
  • It is not possible to successfully put a centre eye splice in a rope of 3 strand construction.

 

LIROS 3 Strand and Anchorplait Nylon - Rope Constrcution and Properties Comparison:

LIROS 3 Strand Nylon Article 00110

  • Thermofixed twisted lay construction 100% high tenacity Nylon (Polyamide)
  • Manufactured to DIN EN ISO 1140 (previously DIN EN 696, DIN 83330)
  • Spliceable to chain
  • Dependable strength
  • Excellent durability
  • UV and abrasion resistant
  • Excellent shock absorbing elasticity >20% working load stretch
  • LIROS Break Load: 10mm 2400kg ~ 12mm 3300kg ~ 14mm 4400kg ~ 16mm ~ 5600kg ~ 18mm 7000kg - 20mm 8140kg ~ 24mm 11800kg ~ 30mm 17400kg

LIROS 3 Strand Nylon has the same strength and stretch properties as the octoplait version, is less expensive but the twisted lay shrinks when immersed in water causing it to go stiff, especially in the larger diameters.

Overall, a very strong and stretchy mooring warp that represents exceptionally good value when used for semi-permanent mooring but not usually recommended for frequently adjusted and stowed mooring warps due to the stiffening of the line over its lifetime. 

LIROS Anchorplait White Nylon Article 01058JG - 100% Nylon (Polyamide) manufactured exclusively by LIROS Ropes for Jimmy Green Marine with the Jimmy Green designed Easy Splice Markers - this also includes LIROS Octoplait Nylon Article 01058 (plain white)

  • UV stabilised, excellent weathering and wear resistance properties.
  • The 8 strand construction (2 pairs left hand, 2 pairs right hand) gives a balanced performance and no twist under tension.
  • Anchorplait is the rope that won't cockle. In fact it flakes like chain.
  • Ideal for use as a snubbing bridle as it will stay supple for the duration of its working life.
  • LIROS Break Load: 10mm 2400kg ~ 12mm 3300kg ~ 14mm 4400kg ~ 16mm ~ 5600kg ~ 18mm 7000kg - 20mm 8140kg ~ 24mm 11800kg ~ 28mm 15000kg ~ 32mm 20000kg



Read our article ANCHOR SNUBBING - A GUIDE TO TAKING THE SHOCK LOAD OFF YOUR WINDLASS AND CHAIN