New Catwalk

No posts in awhile, but we’re making steady progress here on Take Two.  The latest finished project is the installation of our new catwalk.  The last one, you may recall, exploded under the strain of waves we took over the bow in boisterous conditions.  I didn’t share these pictures before because the wounds were too fresh.

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Can you spot what's missing in that picture?  Apparently the weave of our trampoline nets is too close and doesn’t allow water to drain through fast enough for the amount that was landing on them.  The weather was on our starboard side, and the weight of the water coming over the starboard bow and onto the net caused the bottom and starboard side of the catwalk to separate.

The old catwalk was essentially a box, hardwood sides and ends, plywood top and bottom, painted on the outside and epoxied on the inside, with a teak surface laid on top.  Despite being hollow inside, the thing was heavy, which I didn’t fully realize until trying to haul it out of the water.  And despite the paint and epoxy, there was some rot in the top along the starboard side.  This rot undoubtedly contributed to the old catwalk’s failure.

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Although the catwalk broke, the laces attaching it to the trampoline net did not.  The broken sections fell in the water and were dragged under the boat, becoming a bludgeon that pounded our underside.  I have no idea how much time passed between when the catwalk broke and we discovered it.  It is a good indication of just how much noise there is in a storm that we couldn’t hear the punishment we were receiving below.

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It's hard to get a good picture down there that really shows the damage.  I've taken many, but chose to go with one that had pretty water.  If you can see it, none of that damage is serious and most of it just needs to be faired and painted.  The paint color under the bridgedeck is interesting.  Originally it was a cream color, like the decks.  They painted over the cream with a dayglo orange.  Apparently someone was concerned about the boat laying upside down in the middle of an ocean.  Over the orange, they painted red.  Unfortunately the orange didn't stick very well, which might have been the reason for the red, but it didn't really work.  The whole thing needs to be repainted, which will not be a fun job.  Cosmetic items are pretty low on our priority list and nobody even sees that area.

But the catwalk was a high priority.  The catwalk’s primary purpose is to resist compression between the forward crossbeam and the bridgedeck.  The mast pulls up and aft on the crossbeam.  The pelican striker opposes the upward pull, and the catwalk opposes the aft pull.  So it is structural from the designer's standpoint.  The secondary function is a solid platform to walk on when dealing with the anchor.  Operating the boat is tricky without it, so replacing the catwalk was a "must" before we start using the boat again.

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Whenever something fails on Take Two, we see it as an opportunity to make the thing better, and the new catwalk was designed to correct the flaws of the previous one.  It has solid sides and ends like the old catwalk, but there are several cross members mortise and tenoned into the sides, strengthening it in the dimension that the old one broke.  Thin slats rest on these cross members to make the top.  There is no bottom.  It weighs maybe 25 pounds, while the old one was probably around 75.  Extra weight on the bow can be put to better use in a larger anchor.

The open bottom means there are no hidden places where rot and weakness can fester.  It also allows the slatted top, which is good for washing off the muck and weed that often comes up on the chain.  Both reduce weight.  But the slats are thin and not strong enough without additional support.  The cross members provide this support, and also help resist side loads from the nets.  We don’t have a chain stopper and couldn't figure out how to do it before.  If we wanted to add one now it could be bolted through one of those cross members.

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Teak was chosen for its rot resistance and light weight.  We generally do not like teak on our boat, as we have no desire to maintain it.  However, we did not mind the raw teak surface on the old catwalk and felt it stood up well to the anchor chain running over it.  We briefly considered fiberglass but decided that was a loser on cost, weight, and resisting abrasion from the chain.  

Like most projects, the new catwalk opened the door for making other changes, and we were never quite satisfied with the way the trampoline nets were attached.  They used to be double laced through stamped eyestraps screwed into the catwalk and rest of the boat.  We had repeated problems with chafe on the lacing lines which required us to replace them about twice a year.  And the eyestraps sawing through the lacing was very loud inside the boat; like a big violin.  

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We contacted Sunrise Yacht Products, the company that made our nets, and they recommended a perpendicular lacing pattern which allows less movement, and a track and slide attachment to the boat instead of the eyestraps.  They sell track, slides, and lacing for this purpose.

The track appears to be specially made and I could find no other source for it.  It is like awning track, but has a much heavier wall thickness.  It comes in two different extrusions for attachment to surfaces perpendicular or parallel to the load.  The slides are made by Bainbridge and can be found cheaper online, but Sunrise customizes them by bending the bail to keep the laces centered.  The line they sell for laces is a ¼” polyester double-braid.  

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We found we could get much better tension on the nets with the new lacing pattern, and we’re very pleased with how the new arrangement looks and feels.  Unfortunately the teak won’t remain bright and pretty for long.  It will weather to a dull gray color unless we maintain it, which we won’t.

The nets themselves were undamaged in our little incident, and are possibly indestructible.  Despite the drainage problem, we really like them and we’re not planning to replace them anytime soon.  We will however try to avoid dumping that much water on them again.  If necessary, I’ll cut the laces next time rather than risk damage.