The Rules of using Dyneema for lifelines:
- Use line at least 3 times the strength of the wire in the same application.
- This gives you a huge factor of safety for strength and the stretch will be similar to what the wire was. Sizing this way gives you time to fix chafe issues when they become apparent (fuzziness in the line which is highly visible) knowing that you have alot of strength left in the line. There is no weight penalty for upsizing the line and the cost increase is minimal. We almost always use 5 mm heat stretched Dyneema (Dynice Dux, 11,000 lbs Break strength) but have used 7 mm (Dynice Dux, 16,000 lbs break strength) on occasion when asked for even more of a safety factor. We ALWAYS use it naked so you can fully inspect it. Inspectablity is a very valuable feature so think twice before covering it up. Ask the US Coast Guard what inspectability means to them.
- Use the strongest and toughest line you can, heat stretched Dyneema.
- Heat Stretched Dyneema (Dynice Dux) is much tougher than normal Dyneema and will give you much more life if used properly.
- No sharp edges.
- It is very important to protect for chafing issues. Obvious sharp edges need to be blunted and/or the line needs to have a sacrificial cover on it. Areas that are questionable can be checked frequently after installation and protection added after installation. There are numerous sacrificial protective covers on the market, simple and tough rigging tape is just one.
- Generous bending radii and luggage tag when you can.
- Minimum of a 5/1 is highly recommended for a static bending ratio. If you have a smaller bending ratio then you can luggage tag and half the load in the same situation for a longer life.
- Set everything up for easy visual inspection.
- Keep it naked, with the exception of high chafe areas that need to be covered. Use a sacrificial cover that can be easily removed for inspection.
- Stanchion pass thru's can easily be inspected by loosening lashings and sliding the line down to expose the pass thru area.
- Set up routine inspection schedule.
- This is easy and just means you look around before and during sailing, which you should be doing already. Dyneema is very talkative and it will tell you when it has issues. Both UV and Chafe present visible cues of damage and the line gets fuzzy. Its like a flashing red lite if you look for it, JUST LOOK.
- Inspect often
- The large factor of safety for strength means that you will have a generous window of time from when you start to see chafe and when you need to fix it. Keep in mind that you have a 12 strand line (in most cases), 1 strand is 1/12 of the strength of the line. If one strand is cut thru you have lost 1/12 the strength of the line. This is the thinking that needs to go thru your head while inspecting the line.
Benefits of using Colligo Dux for synthetic lifelines
1. Fully inspectable if you don't cover it up,
2. Visual indicators for chafe and UV because it gets fuzzy.
3. No corrosion-ever, it is lighter and 'DIY'- friendly, much higher strength therefore factor of safety.
Because of its inspectability, Dyneema lifelines are safer than steel lifelines when implemented correctly. Dyneema is not steel and it has different rules than steel and these need to be followed correctly.