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Trap shock cord setup options
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Author:  mboyer68 [ Sun Oct 17, 2010 8:34 am ]
Post subject:  Trap shock cord setup options

I saw a boat setup with blocks to reduce friction for pulling out shock cord for trapping. The setup below is what i saw. Are there any other ways to get this done ? I will be using the Harken micro blocks as seen below. I think the setup is good just wondering if there's a better way.

The setup i saw had a line tied through the two shock cord ports with blocks attached to it.

The blocks i bought:

Author:  Harry Murphey [ Sun Oct 17, 2010 11:45 am ]
Post subject:  Re: Trap shock cord setup options


If you research my posts you will find that I have posted a trapeze system very similiar to what you have there ..... except ...

1) I tie the two blocks together w/ 1/8" spectra/vectra UNDER the gunwale ....and I have micro blocks tied fore and aft at the padeyes under the gunwale also ....

Now w/ approx 25' of 3/16 bungie start w/ the crew/fore trap ... tie the bungie there ... run through the micro block tied at the gunwale ... go forward to the micro block there .... thread through (bottom to top) .... and go all the way to the aft microblock tied under the gunwale ... thread through that block (top to bottom) ... return to the micro block tie at the skipper's trap ... thread through it ... and tie of to the skipper's trap. Now you have a continious bungie trap system that works w/ both a H18 w/ magnum wings or a standard "SE" H18 w/ lots of stretch available for traping out ...particulary when trapped very far aft on a screaming reach.

Oh ... see that clevis pin w/ ring attaching the side stay/shroud to the "anchor pin" in the middle of the picture????

Do one of two things ... before you lose it and de-mast!!!!!!!!
2) Re-place that pin w/ a shackle w/ a captive pin that can not come out. (I sometimes rig a "barberhauler" to that shackle ... not class legal for racing but does shape the jib nicely for reaches when "fun" sailing)


Author:  mboyer68 [ Sun Oct 17, 2010 3:44 pm ]
Post subject:  Re: Trap shock cord setup options


Thank you so much for the information. The boat in the picture isn't mine - i don't know who owns it ?! I saw it and noticed the upgrade and took a picture.

How did you tie the micro blocks to the boat ? You lost me on the description - i read it and tried to figure it out...Any chance you could post a picture ? A picture is worth a thousand words !

I'm sure if you posted a few pictures of your work (other mods) with brief descriptions, a bunch of people would benefit.

Thanks again !

Author:  Harry Murphey [ Sun Oct 17, 2010 6:39 pm ]
Post subject:  Re: Trap shock cord setup options

Hi (again),

There seems to be some confusion about my last post .... let me try and explain/illuminate my concept alittle better ....

This system will provide enough stretch so that on a H18SE you can "trap out" anywhere along the length of the boat w/o having to fight against the pull of the trapeze bungie cord and will require no modifications/adjustments to the trapeze system (except for maybe trap heigth) if you have Magnum/SX Wings and want to "trap out' off of them , or need to remove the wings to be "class legal" for racing .....

1) (8) Small Blocks divided into (4/side): Best- (4) Harkin "Micro" blocks and (4) Harkin "Air" blocks or just (8) total "Micro" blocks.

2) Approx 50ft of 3/16 bungie cord (25ft/side)

3) 1/8" Spectr/vectra cut into (4) 1ft lg pieces, and (2) 2ft lg pieces.

The Harkin "Micro" blocks are perfect for the (4) blocks that you attach to the padeyes under the gunwales using (4) 1ft lg pieces of spectra/vectra of line that are located near both bows and both sterns. You will find that the "Micro" blocks fit/tuck snugly up under the gunwale after you "lace" the 3/16" bungie cord ... but, I like either the Harkin "Air/Micro" blocks because they have ballbearings w/ a metal housing that as you step on/stomp when "traped out" will not break .... the "Air" blocks are just slightly smaller and therefore there is slightly less "under foot" at the mid-ship gunwale fairlead location(s), both will work, Ok?

Next, Using the 2ft long pieces of spectra/vectra ... tie the "Air" (or "Micro") blocks at the gunwale fairleads for the trapeze system. I loop the line, w/ the Harkin blocks on the outside of the gunwale through both fairleads and tie the two ends together so all the line, and knot, is tucked up under the gunwale w/ the blocks on the outside of the gunwale, on small loops w/ the smallest/shortest/tightest length of line possible. (The first time I did this I spliced 1ft pigtails of 1/4" 3-strand to each block ... fed that through the fairleads and tied the two ends together ... pulling against each other .... looped 1/8" spectra/vectra w/ knots is a little easier and quicker ....)

Now to "lace" the 25' (approx) of bungie cord .... starting w/the crew/forward trap ... attach/tie one end of the bungie to the end of trap line (usually 1/4"dia line w/ dogbone or easy hook/loop at the other end to use w/ trapeze harness) .... pass the free end of the bungie through the "Air/Micro" block attached to the loop at the forward/crew fairlead, going from mid-ships forward to the bow .... at the bow thread the bungie through/around the micro block there attached/tied to the padeye under the gunwale w/ the 1ft lg piece of line, going from bottom to top then tuck the "Micro" up under the gunwale ..... take the end of the bungie all the way aft to the "micro" block attached/tied to the padeye there located under the gunwale .... thread bungie through/around the "micro" block top to bottom ..... now proceed forward to the "air/micro" block attached/tied at the skipper's/aft fairlead ... thread it through from aft to mid-ships and then tie to skipper's trap line.

You will find that if you lace it like this the bungie will "roll over/under the gunwale .... feed up/through/around the micro blocks at both end of the boat and run neatly tuck up under the gunwale, running fore/aft the length of the boat.

Unfortunately I'm "computer challenged" and am lucky I know how to turn this thing on .... posting pic's/diagrams .... isn't that in Computer 102 ... the advanced class????

Author:  Tom Machette [ Mon Oct 18, 2010 4:06 pm ]
Post subject:  Re: Trap shock cord setup options

Do I have it Correct harry?

Is this class legal?

Author:  srm [ Mon Oct 18, 2010 4:24 pm ]
Post subject:  Re: Trap shock cord setup options

Tom Machette wrote:
Is this class legal?


b) Trapeze shock cords may lead from different
fairleads than those supplied by the HOBIE
CAT CO. but shall lead through the hull


Author:  Harry Murphey [ Mon Oct 18, 2010 5:24 pm ]
Post subject:  Re: Trap shock cord setup options


That's a perfect diagram of the system I installed on my boat ..... and SRM is quite correct that it is NOT class legal.

The non-class legal part/issue is that the bungie cord does not feed/pass through the actual fairlead .... I believe the intent of the rule is not to be able to re-locate the trap wires .... by attaching the "Air/Micro" blocks as tightly as possible I believe I'm not violating the "intent" of the rule ... but only making the trapeze system fully functional.

As I also have a set of Magnum Wings that I take on and off constantly, and I was tired changing my trapeze system, I experimented w/ this idea and it works well. Some of the guys said that if I ever got my procrastinating butt in gear they would support a rules change to allow this "upgrade". But since the H18 is a International Class all rules changes must be approved by the IHCA .... that's too much bureacracy/paperwork for me to deal w/.

Author:  srm [ Mon Oct 18, 2010 6:57 pm ]
Post subject:  Re: Trap shock cord setup options

Harry Murphey wrote:
I believe the intent of the rule is not to be able to re-locate the trap wires.

Actually, relocating the trap wires is totally within the rules.

b) Trapeze shock cords may lead from different
fairleads than those supplied by the HOBIE
but shall lead through the hull


Author:  gregco [ Mon Oct 18, 2010 8:33 pm ]
Post subject:  Re: Trap shock cord setup options

I spent a fair bit of time last winter trying to figure out this particular rule, to understand the intent of the rule and if there is any room to make basic improvements on what I think is only a barely adequate shock cord system.

I read everything I could find on the topic. Asked questions of H18 sailors. I eventually gave up and made the best I could of the basic system, a system that I feel doesn't enhance a skipper's or crew's best possible control of the boat, limits on-the-wire movement in all trapeze conditions, and reduces safety due to constrictions caused by the limited scope of the shock cord.

So, srm, can you please talk in detail about your statement, "Actually, relocating the trap wires is totally within the rules," and to what extent within the rules one can do this? Can we move the hull flanges to wherever we want on the gunwale? And as long as the shock cord passes through the flange, can we use a similar single cord system that Harry uses?

Thanks in advance for your response.

Greg LaLiberte
H18, Colorado

Author:  Sail Revolution [ Tue Oct 19, 2010 8:33 am ]
Post subject:  Re: Trap shock cord setup options

I just can not for the life of me understand why this would be better. That's a lot of hardware and exposed line and shock cord that's just going to get in the way.

Can someone please explain why it's worth adding $50 worth of weight right where you're going to be stepping on it and getting it tangled all the time?

Oh, and I am on the bylaws committee...

Author:  srm [ Tue Oct 19, 2010 9:27 am ]
Post subject:  Re: Trap shock cord setup options

I'm not going to delve into the intent of this particular rule. I didn't write it. What I posted was the letter of the law, as it were. I will say that the Hobie 18 class is a strict one-design class, so changes, particularly those that add complexity, expense, or perceived unfair advantage, are heavily frowned upon.

My interpretation of the rule is that you can move the thru-flange fairlead anywhere along the flange that you want, but the bungee cord must pass through that fairlead. I don't believe there are any limitations on whether you use two separate or one continuous bungee.

Personally, I agree 100% with Jeremy. I think the stock system works fine. The last thing I want around my feet are more lines and hardware. I prefer to keep my boat as clean and clutter free as possible. Keep in mind that the "upgraded" system proposed above not only has lines and pulleys added to the side of the hull, but also the trapeze bungee will be pulled up and over the hull flange so that it is no longer neatly stowed under the flange. Ugly and sloppy in my opinion.

If you sail a magnum/SX 18, then I could see the potential need for a system that allows for more travel (in that case I might even devise a system that stored the bungee up under the wings). But for racing or non-winged sailing, I would just stick with stock system- its simple and works fine.


Author:  RushMan [ Tue Oct 19, 2010 1:16 pm ]
Post subject:  Re: Trap shock cord setup options

I have a system similiar to this but without the pulleys near the exit holes.

One long elastic, two small micro blocks at each end, enough stretch for when I have the wings on and tight enough when racing.

Best of both worlds.

Author:  Harry Murphey [ Tue Oct 19, 2010 4:11 pm ]
Post subject:  Re: Trap shock cord setup options


I recieved that same argument years ago .... the reality is that as designed the trapeze retracting system/bungie is difficult to work w/ due to the the fact that you only get some much stretch per foot of bungie cord ... and it is not 100% ... which is what you need to trap out further aft when on a reach. So you struggle against the pull of the bungie cord constantly.

So the answer is to lengthen the length/amount of bungie cord so that you have the additional stretch needed to trap off magnum wings or back at the rear crossbar

Now you can install the "continious" bungie system and still feed it through the fairleads .... I believe that is "class legal" but .... the bungie cord wears out fairly quickly and then quess what ..... the bungie cord breaks in the middle of a race which causes a even bigger problem of a trap wire w/ handle and dogbone/easy hook loop/ball now swinging around wildly .... smacking people in the face/eyes/head.

The possibilty of stepping on the bungie cord or the slight wieght gain due to the small blocks is such a minor factor when compared to the the difficulty of using the "stock" trapeze system and the increased possibility of the bungie breaking sooner as to be laughable in my opinion.(If I'm that worried about wieght ... I'll just not eat breakfast as I have a few pounds I can lose)

Plus you add the factor of Magnum Wings .... removing and re-installing .... which w/ the stock system especially does not have enough stretch w/o spending time to re-adjust the trapeze system (lengthing/shortening lines/bungies as required) and you just make it more difficult for a H18 Mag to remove their wings to be "class legal" for racing.

And quess what .... they don't and just stay away. I'm famous in Div11 for being the last boat off the beach .... and you want to add even more time/difficulty to my getting ready for a race?????

Everyone who has trapped off my boat w/ or w/o wings is amazed at how easy it is to use my trapeze system .... has no complaints and even comment on that fact.

Oh, you want to move the fairleads???? Now you have just created obstructions to getting on and off the boat spaced further apart .... I actually like were the traps are located near the shrouds as they make a single neat obstruction that is easy to work around.

Now my boat has been rigged this way for +20yrs .... every H18 Competitor in Div11 knows this ... some have copied the system completely ... some just the continious bungie part .... some not at all .... but either way it will be rigged this way for as long as I race this boat ....

Now the other Div11 H18 Racers have never protested me over all the years .... and if someone does ....I quess I'll be DSQ'd .....

But then you will never see me at another Hobie Points Regatta again .... as this rule is IMHO just Chickensh-t .... I own the boat .... and as owner/captain, I determine what I feel is safe and works ... ON MY OWN BOAT .... not someone else.

When the rules get to "out of hand" .... I can always race "Open Class"

So before you pass judgement ... rig up a H18 Mag w/ this system .... run your own tests .... trap off the wings .... remove the wings .... trap off again. Tell me how it works out .... I'll bet you a case of beer (in bottles) that you will like the ease of use and find that you have no issues ..... (I never have)

Author:  HOBIE 911 [ Tue Oct 19, 2010 6:47 pm ]
Post subject:  Re: Trap shock cord setup options

That diagram is not a class legal set up. The bungee that attaches to the trap wire MUST pass thru the fairlead on the lip. In the diagram, there is a line that passes thru the fairleads fore and aft and attach to micro-blocks. The trap bungees then pass thru the blocks. This does not meet the class rules.

Author:  gregco [ Tue Oct 19, 2010 9:00 pm ]
Post subject:  Re: Trap shock cord setup options

The rule is finally becoming clear to me. It helps to now know that the "flange" is the hull lip (or gunwale referred to above) rather than the fitting (the fairlead) that the shock cord passes through. Clearly, to be class legal, we can place fairleads wherever we like along the hull flange as long as the shock cords pass through the fairleads. Whatever we do with the other end of the shock cord is our own business as that is not addressed in the rules.

My concern for this issue partly stems from racing in the NAC's at McConaughy last month. On the final day in about 20+mph winds sailing upwind, I was temporarily positioned on the weather hull at the forward crossbar while wrestling through some tight maneuvers. My 14-yr-old daughter/crew was just forward of me and unable to access her trap wire because of how I was positioned. She nearly fell in as a result of her attempts. Being able to reposition the trap wire shock cord to a forward heavy weather fairlead would be beneficial in that kind of situation, also making it much easier to trap in a more forward position.

Any issues with this thinking?


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