The Offshore Voyaging Reference Site

An Efficient Foredeck Centreline Jackline

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Last fall we wrote about our new centreline jacklines that enabled us to work our boat from cockpit to mast without resorting to clipping to sidedeck jacklines.

(If you doubt how dangerous using sidedeck jacklines is, please read, or reread, the last three chapters in this Online Book.)

Work Left To Do

But we were still left with installing a centreline jackline from mast to bow. A project with some problems to solve:

  • Because the cabin top extends forward of the mast, this jackline would be at ankle height on the foredeck, resulting in a nasty trip risk while coming alongside, anchoring, or wandering around the deck with a sundowner—this could be a bigger, or at least more frequent, risk than being dragged.
  • Interference with operation of the windlass.
  • Difficulty of stowing our dinghy in its inshore position on the foredeck.

Over the winter, encouraged by this comment from Dick Stevenson, we thought about the problem and came up with a centreline jackline from mast to bow.

The Details

The secret to making all of this work, and dealing with the above-listed issues, was to make the foredeck jackline easy to install and remove as well as tension.

It’s about the details…it’s always about the details. Let’s take a look:


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Dick Stevenson

Hi John,
Needless to say, I like the idea and its additional details.
I know we are talking jacklines here (so move this if necessary), but the goal is to keep people on board and, looking at your picture of the tether hanging over the toerail and under the lifelines with its person end hanging just above the water—empty– gives me a bit of the willies.
I wonder whether it is time to re-consider netting. I know racers have done so to keep sails from skidding overboard and I used netting to catch my children (never happened but did stop a few tools from going into the deep). I am thinking large square netting done with some strong small diameter (HM) line. Just enough that would ensure a person would get tangled up BEFORE they go overboard and while still on the deck side of the lifelines.
If the majority of POB go over the lifelines, then this idea makes less sense. I wonder whether there are stats on POB and how they get there: over, between top and middle, or deck to middle. I know my one real scare I was slipping out under the lines on the deck.
Other considerations: Put this netting on both levels of the lifelines or just the bottom– Just the foredeck or all the way back to the gate (front end of the dodger)—What boat operations get interfered with (both sailing and at anchor)?
Initial thoughts.
My best, Dick Stevenson, s/v Alchemy

Marc Dacey

You’ve already said what I was going to say, Dick! I think just the bottom (gunwales to mid-stanchion lifeline) would suffice, given enough height on the pulpit. Funny, I had foredeck netting when I got my first boat 17 years ago: I removed it when I decided I wasn’t going to race the boat, and now I’m rethinking that decision for ocean work on the new boat, which has pretty high and very sturdy piperails. Like you, I’ve never gone over them, but I did go under a lifeline in a sudden squall on the beam and was only saved from an almost certain death at night well offshore by a short tether. It does focus the mind.
John, your jackline tensioning blocks are great. Well done.

ChrisW

During my military training rappelling was one of the skills we had to master. After committing to stepping over the edge of a cliff tall enough to kill, It was fun, secure and safe provided one didn’t hot dog.

Then came sailing, and every time I looked at the fore deck in seas over three inches, I wondered why I couldn’t be tethered from above as well as from below.

Vertical tether (halyard) interference with the outer jib (and less so with the inner) were the main issue — one more detail to deal with in a potentially dangerous situation. However, once I worked out the geometry, I ended up with an approach that, absent halyard or mast failure would keep me out of the water at normal heel angles. I have considered adding blocks well down the mast to be rigged somewhat like running backstays as this would shorten the arc of swing should my grip otherwise fail.

It is imperfect, but it it is perfectible. It requires three tethers, but three is a very good number in structural engineering.

Drew Frye

I’d love to here a further explanation. I tried using a halyard at the suggestion of a cat sailor that feared (irrationally) tramp failure. There were several problems:
1. If there is slack it wraps around a spreader or something equivalent. I think most sailors hate the potential for tangles aloft.
2. If there is no slack you are prevented from getting low in a bump. In fact, it can lift you right off your feet as you move forward.
3. Problem 2 is worse if the cabin is raised.

In short, I found it to be a nightmare.

My jackline solution is different from John’s, but it is a catamaran solution, so I’ll leave it alone. What I am most struck by as I look at John’s solution and the foredeck that it is on, is how different the problems and solutions must be. It’s the principles that matter and the forethought a good system requires.

ChrisW

Hi John,

Yeh, its been a while. The sailing here approaches non-existent and health, family matters and bad weather-windows have kept us from the Abacos. (…and Florida is quite hostile toward people who have an anchor and prefer to use it.)

Yes, the flail of a halyard is certainly daunting. I’ve seen one bend a headfoil with one solid whack.

Your comment about tension tending sent me off on a tangent.

I wonder if we think of something small diameter with high tensile strength ala Spectra set up taught in an endless loop from mast base to an appropriate height. This line could be equipped with hard or soft loops for snapping into and a stopper for belay and position control. Its windage should be on the order of a flag halyard .

Chris

ChrisW

Yep, I may give it a shot. An osprey with a seven foot wingspan(!) decided our wind instruments were annoying, so she tore them off. So I have a masthead trip in the near future.

Jim Ferguson

Great comments everywhere. On Maggie we have been using that center backline technique as well and I will use John’s technique for snugging it up. Lanyards are attached and sit at the front of the mast I re-attach at the mast pulpit when I go forward. Between the cockpit and the mast on either side, I have been using my running backs which work very well using a very short lanyard. They attach just below the upper spreaders. I can work both sides of the mast for reefing. Since we’ve been in lower latitudes the last few years our we don’t set the staysail. It is a work in progress, but I’ve been pleased so far.

Thanks,
Jim Ferguson
S/V Maggie

Mathieu

How about stopping the jackline just aft of (or on) the windlass? It looks like your 5ft tether would be long enough to let you work on the bow and you reduce the risk of drag a bit.

Dick Stevenson

Hi Mathieu,
That is exactly what we do on Alchemy. We dead-end the jackline just aft of our staysail which, on our smaller 40 foot hull, allows me to reach out to the asym downhaul, as far forward as I am likely to need.
Dick Stevenson, s/v Alchemy

Raymond Smith

How, where is the jackline tethered and tensioned at the aft end?