Posted on behalf of Ben Hudson :

I am looking at redesigning the current lifelines used on sailing yachts; trying to incorporate a few new features to enhance the safety for sailors.

The key features that I 'm going to try to incorporate are foot holds to help the sailor get back on board should the fall overboard, a sensor which recognises if the sailor falls overboard the auto pilot kicks in and points the boat into wind therefore stopping the boat making it easier to haul yourself/be lifted back on board.

I am also looking into designing a harness which can be worn constantly including when sleeping meaning that if there is a sudden problem which you need to leave the cockpit for, you don 't have to use time putting on a life jacket and rather just clip into the lifeline to go and sort the problem out.

- Do you feel there is anything else which could be incorporated into the design to further enhance the safety of sailors?
- Would you buy such a product as described above, if so what would you expect to pay for it?
- In what conditions do you use lifelines and do you always use them at night?

Thank you so much for your help with this! I look forward to the responses.

Kind Regards,
Ben Hudson

Hi Ben,

There 's certainly some work that needs doing on yachtsmen 's safety harnesses.
[ol]
[li]I use a belt, rather than a harness. This is more comfortable (only one buckle), and the tether attachment point can be moved around to be behind me when I have work to do. The mid-chest attachment point of a harness is inconvenient when winding a winch, for example. But a belt must be used with a short tether, such that it 's impossible to fall overside, or fall far. You wouldn 't want to be towed through the water.[/li]
[li]Have a look at industrial full-body harnesses. These generally have the tether attached between the shoulder blades - much better for working, for being suspended from after a fall, and for being towed through the water at speed[/li]
[/ol]

I use my belt when I have to reach high to work, when I need both hands for the job, when I recognise that I 'm not working safely, when the boat 's motion is jerky. Not always at night, it 's not the dark that makes the difference so much as the sea state. Better to assume that if you fall overside unattached, you become invisible to remaining crew very quickly unless the sea is calm, and might as well consider yourself as good as dead.

Ben,
Shock loading is an issue. Any climber will understand this as the forces on a static tether can be very considerable even if a fall is short. That 's why climbing ropes are quite stretchy. You might like to huild into the tether a mechanism for reducing the shock loading. Modern climbing kit used on Via Ferratas have a device that will do this. Here is a link to such a device designed to take the shock loading out of a short fall http://www.gooutdoors.co.uk/black-diamond-iron-cruiser-via-ferrata-set-p294107?gclid=CjwKEAiA6YDBBRDwtpTQnYzx5lASJAC57ObMP0Th6sqn9qq1zGk5cj1BfRTJjeYbsLqPXQj6TSkj0hoCrLLw_wcB&gclsrc=aw.ds
Simon

Ben,
Shock loading is an issue. Any climber will understand this as the forces on a static tether can be very considerable even if a fall is short. That 's why climbing ropes are quite stretchy. You might like to huild into the tether a mechanism for reducing the shock loading. Modern climbing kit used on Via Ferratas have a device that will do this. Here is a link to such a device designed to take the shock loading out of a short fall http://www.gooutdoors.co.uk/black-diamond-iron-cruiser-via-ferrata-set-p294107?gclid=CjwKEAiA6YDBBRDwtpTQnYzx5lASJAC57ObMP0Th6sqn9qq1zGk5cj1BfRTJjeYbsLqPXQj6TSkj0hoCrLLw_wcB&gclsrc=aw.ds
Simon

Ben,
In the interest of not re-inventing the wheel, much of what you are interested in has been exhaustively examined by a very experienced group of sailors on the Attainable Adventure Cruising web site and has led to a number of conclusions/recommendations. The examination is far to detailed to reiterate here and the conclusions, to make sense, follow from immersing yourself in the details, so I will not try. The only caveat is that to review AAC 's past material, there is a $20 membership fee/year. I suspect you will find the wealth and breadth of information well worth it.
If you join AAC and review the material there, please come back with a report on whether you found it helpful and what you were looking for.
My best, Dick Stevenson, s/v Alchemy