The Jimmy Green Rigging Team can advise you on the correct specification when fitting Ultra-Performance Jackstay Lifelines in 12 strand Hollow-Braid, 100% Dyneema fibre rope.
Dyneema Fibre Jackstay Lifelines are spliced and finished to your individual requirements in the Jimmy Green Splicing Centre, the hub of our Custom Rigging Service operation.
Dyneema Jackstay Lifelines are available to order online in 5mm or 6mm diameter in a choice of ropes - LIROS D Pro Static or Hampidjan DynIce Dux.
Ordering Jackstay Lifelines in Dyneema:
- Select your preferred spliced option for one end - the most flexible arrangement is the long 'cow hitch' loop splice
- Enter the required length - make an allowance for adding your choice of fitting to the second end and making off with lanyards.
- Select your preferred spliced option for the other end - the most flexible arrangement is a repeat of the long 'cow hitch' loop splice
Dyneema Jackstay Lifeline Break Loads
LIROS Break Load for D Pro Static - 5mm = 2450kg, 6mm = 4050kg
Hampidjan Break Load for DynIce Dux - 5mm = 4.8 tonnes, 6mm = 6.8 tonnes
N.B. All wire/rope splicing and sewing marginally reduces the breaking strain of the finished product. Hampidjan publish a Spliced Break Load i.e. the strength of the line after it has been spliced DynIce Dux Spliced Break Load - 5mm = 4.3 tonnes, 6mm = 6.1 tonnes
Dyneema Stretch Properties with regard to setting up Jackstay Lifelines
LIROS D Pro Static – Near zero elongation and creep
Hampidjan DynIce - Near zero constructional stretch and creep
Dyneema UV and Abrasion Factors with regard to Jackstays and Lifelines: Dyneema fibre has inherently good UV and abrasion resistance properties, not far behind polyester which is excellent. However, resilience is considerably enhanced by a special additional process. LIROS D Pro Static is additionally protected by a PU impregnation process - the LIROS Coating System provides extra UV and abrasion resistance. Hampidjan DynIce is additionally protected by a coating treatment - Hampidjan impregnation with Durapur for added protection and improved abrasion resistance.
Jimmy Green Dyneema Fibre Rope Jackstay Lifeline Replacement:
All the fibre rope options are much stronger than 5mm wire and all the options (except for 5mm LIROS D Pro Static) are stronger than 6mm wire.
Cow Hitch Spliced Loops are extremely useful for attaching a line to an end fitting or to a fixed point - a cow hitch loop is a long soft loop spliced into the end of the line. The loop is approximately 75mm long when laid flat and pulled out straight. End Fitting - pass the long loop through the eye and over the top of the fitting to form a cow hitch on the eye. Fixed point - pass the long loop around the fixed point e.g. a pushpit rail upright, thread the other end of the line into the long loop and pull the entire length of the line through until it is tight.
Aim to set up your Jackstays so that the ropes have the maximum possible radius of turn around eyes/pins/fittings
Team Jimmy Green suggest that you regard 5mm DynIce Dux as the benchmark rope for fibre lifelines. D Pro Static is the LIROS top quality equivalent rope so makes a good alternative. Upgrade to 6mm if you prefer the belt and braces approach, although 6mm is generally only for larger yachts or for ocean-going adventurers.
Fibre Rope options have minimal elongation compared with wire so they can be tensioned satisfactorily with lanyards. Team Jimmy Green suggest lanyards made from 3mm Dyneema with a commensurate number of passes to achieve a break load comparable with the static part.
Dyneema has excellent abrasion resistance but will be more prone to damage, from unkind abrasive snagging points than wire or webbing, so it is extremely important to ensure that all the deck fittings that they come into contact with are sympathetically smooth.
Anti-Chafe Sleeving provides excellent abrasion resistance where a Jackstay Lifeline has to lay against a deck fitting permanently e.g. a short length of Technora or Dyneema hollowbraid, whipped securely into position, or even a neat suede leather serving. Ensure that the safety tether hook can pass easily over any sleeving.
Dyneema can be visually monitored for signs of wear or other deterioration. Any damage can then easily be identified and addressed well before there is any chance of failure - Dyneema exhibits a loss of function by going fuzzy (or furry) but the deterioration from this point should be slow enough for it to be replaced in good time - prevention is better than cure.