Not all Tramps are created equally: the score on catamaran trampolines

My editor (Miss “You can’t say that!”) was recently perusing some comparative pictures of trampoline installations that she took at various boat shows. I thought she should write this herself, complete with her own unique colourful language and derisive snorts. She gracefully declined, so here I am again.

Why have a trampoline anyway?

  • Engineering reasons: to create a large area of deck space with minimal weight and maximum drainage.
  • Safety reasons: to provide safe access to the crossbeam, ground tackle, forestay and bowsprit.
  • For “the hell of it” reasons: cool place to lie around and experience the interplay with seas.

Design Criteria

  • make the deck/tramp interface flush and free of trip hazards
  • use construction methods and materials appropriate to the vessel’s use e.g. ultra-light and bouncy may be appropriate for sunshine boats or lightweights when your joints are still young but do you want to be negotiating such a surface when dealing with foredeck issues in a serious blow?
  • make the installation as clean and elegant as possible for best aesthetics and easy maintenance/inspection
  • note that tighter lacing and less elastic materials increase the catenary loads on the surrounding structures and fittings
  • the crossbeam, anchoring and mooring provisions as well as the  lifeline arrangements are integral to the design, we should include them in the considerations

The relevant ISO Standards pertinent to CE approval for various classes of voyage are:

15084 Small craft – Anchoring, mooring and towing-Strong points

This International Standard specifies requirements for strong points for attaching chains, cables and lines for anchoring, mooring and towing small craft. Includes specifications for cleats, winches, padeyes.

15085 Small craft- Man-overboard prevention and recovery

This International Standard specifies the design as well as the construction and strength requirements for safety devices and arrangements intended to minimize the risk of falling overboard, and requirements to facilitate reboarding. Includes definition of working decks, obstructions and trip hazards, footstops, lifelines, lanyard hooking points, reboarding ladders, trampolines, non-skid etc.

Note: Oddly enough, the standard does not demand lifelines across the bows if the vessel has crossbeam stay; regardless of the oceangoing category or their ineffectiveness as lifelines, it’s up to the builder. Some lobbying with the CE Approvals bureaucrats took place I guess.  A builder may also theoretically define the “working deck” at his discretion and thereby avoid sticky issues with a notice such as “Don’t Walk Here”.

What were they thinking?

What follows is the editor’s “What were They Thinking?” scoring game, be kind now.

example of catamaran trampoline

Resourceful Lads

  • Flush: Here and there
  • Trip hazard free: @#$%U&*&^*^&$  (ever stub your toe? twice?)  You could paint the chain with Dayglo paint I suppose.
  • Lifelines: No, dodged the standards there, thanks to the crossbeam wire.
  • Footstops: Don’t see any.
  • Elegant: Lots of parts anyway, designed by the patron saint of sail slide makers.  Rusty chain a little harsh perhaps?  Reminiscent of my vintage folding lawn chairs.
  • Materials: Pretty tough stuff, but only stitched along the perimeter loops, better keep it real tight or the little squares could expand to pass your foot through.
  • Anchoring: Centre ramp is quite an interesting assembly of disparate parts isn’t it?  With the anchor deployed so far aft of the bows there needs be a good provision for bridling, though the necessary strong points aren’t evident – I hope the transverse cleats on the crossbeam are not expected to do it, they are at their worst possible orientation to take a pull forward– must be something else we can’t see.
  • Score: 5/10. They worked really hard.
Example of trampoline on a catamaran

Big name boat here, be careful what you say.

  • Flush: Well, centre ramp is flush.  Say, did you ever forget that last step down in the dark?  I suppose the kiddies and their toys could be confined nicely within the sandbox. Something reminiscent of curb stones here, or empty swimming pools maybe?
  • Trip hazard free: No apparent toe stubbers anyway, injuries being confined to the larger body parts.
  • Lifelines: OK, they are there, they had no choice as there is no crossbeam.
  • Footstops: No. (some ISO Standard loophole?)
  • Elegant: Gotta admire the fancy ropework, designer must be the patron saint of macrame, poor owner who has to deal with it himself, boat must come with one of those incomprehensible knot tying instruction sheets.  You would really want to learn some fishing net patching methods I suspect.
  • Materials: Pretty lightweight flexi stuff for all the heavy work employed to hold it.  Ever notice how backyard bouncing tramps are all heavily padded around the (flat) edges?
  • Anchoring: Looks like a plan. Can just see one anchor underneath and its bridle made down to the wee cleat there on the pointy bit.  There two each side though so I guess you can double up.
  • Score: 6/10. These guys know better.
Example of trampoline on a catamaran

Another big name boat, but say what you like

  • Flush: Yeah, all round the chasm. Good attention to the moulding and crossbeam heights, – now if the designer had just been allowed to finish the tramp…
  • Trip hazard free: Whole little array of nubbies and toe holes, naw, I’m sure I could get my whole foot through some of them at least.
  • Lifelines: No, dodged the standards there, thanks to the crossbeam wire.
  • Footstops: Yes, visible just aft of the aluminum bow cleat.
  • Elegant: It’s clean, it’s minimalist, it’s cheap actually
  • Materials: Maybe that little continuous lace line is Spectra or some such?  Looks like a single chafe through and there you are, bobbing to the surface watching your transoms diminish from sight.
  • Anchoring: Hey the anchor roller is there for you, when you get a few bucks together, you can buy an anchor and rode.  Gotta wonder about a severe downward load from a stuck anchor, offset so far on the crossbeam.  There goes the crossbeam – there goes the rig. (I guess if you don’t supply an anchor, you don’t need to meet any anchoring strong point standards?)
  • Score: 3/10. It is flush at least, and you can’t fault what isn’t there to buy.
example of a trampoline on a catamaran

Creature from the marshes

  • Flush: Watch it, more than one meaning for that word.
  • Trip hazard free: Whole little array of nubbies again, chain, roller, curbs.
  • Lifelines: Sure, as long as you stay on your feet, and don’t  kneel down to inspect the bridle or anything like that. Having dodged the expense of a crossbeam, I guess they could afford to splurge on a few lifelines.
  • Footstops: Yes, you can see them outboard of the tumbly edged bow “working decks”.
  • Elegant: It’s decorative, sorta like drapery maybe. Why did they even bother?  Wonder how far the front cables sag with a load?  Reminiscent of the portable safety nets at the circus.
  • Materials: Consistent with the curtain theme.  Tough stuff for its size probably.
  • Anchoring: No mystery there, watch your step.  Bridle is made down to padeyes just ahead of the tramp cables, OK.
  • Score: 3/10. Majorly frightening for such a puny installation.
example of catamaran trampoline

Cat cat

  • Flush: Close, but no cigar.
  • Trip hazard free: The common little array of nubbies again, three sides, but tough to stub your toe when the curb is right there to shield them.
  • Lifelines: No. (dodged ISO Standard 15085 with the crossbeam stay, again)
  • Footstops: Solid toe rails are there.
  • Elegant: If you leave off half of the pulpits and all the hull mounted mooring hardware, and the forward lifelines, and most of the anchoring gear, and you are willing to park your ass on a bathroom stool, well its bound to have a clean design look isn’t it.
  • Materials: Looks like the real thing.
  • Anchoring: That little grey bump to port of the  ”A” frame  is the anchor roller.  Guess the anchor and chain cramped the boat show style.  The “transverse cleats on the crossbeam” thing again, how do you bridle or tow this creature? (ISO Standard 15084)
  • Score: 4/10. For the sheer boldness of it.
example of a trampoline on a catamaran

Animal lover

  • Flush: Missed it by that much!
  • Trip hazard free: Other than the low curb, pretty good
  • Lifelines: Lifelines are for chickens.
  • Footstops: Maybe not visible?
  • Elegant: Once again; If you leave off half of the pulpits and all the hull mounted mooring hardware, and the forward lifelines, and most of the anchoring gear, well ….
  • Materials: Good stuff. Another application of bulk sail slides, requiring track unfortunately.
  • Anchoring: That little grey bump to port of the  furling gear tang is the anchor roller.  Rest of the required stuff not nice to look at I guess.  Bloody sideways cleats again, say isn’t that the same crossbeam?  (ISO Standard 15084)
  • Score: 5/10. Could have tried harder.
example of trampoline on a catamaran

Breezy

  • Flush: Oh, well, no apparent intent otherwise.
  • Trip hazard free: Other than the low curbs, pretty smooth.
  • Lifelines: Took it seriously, x3.
  • Footstops: Not only missing but nicely rounded over deck edge. (some ISO Standard loophole?)
  • Elegant: Some pleasing lines and shapes.  Look at all the stuff to deal with.  Is the “A” frame stay tensioning device really better than a turnbuckle?
  • Materials: Good stuff.
  • Anchoring: Looks to be there, at least one of those lines could be a bridle, made down to the bow cleat?
  • Score: 8/10. At this size vessel, the design has to quite be accommodating, give ‘em a break.
trampoline on the Antares 44

Star Bright

  • Flush: Like a fried egg.
  • Trip hazard free: Yeah, except for the jib track boss.
  • Lifelines: Yeah, what a bunch ‘a chickens.
  • Footstops: Yeah, perforated toe rails all round.
  • Elegant: Kinda boring.  Hey, real ass-size bow seats though!
  • Materials: Best stuff, Bainbridge FH592WT Extra HD “SuperTramp
  • Anchoring: I happen to know there are two anchors self-stowed below the flush hatches in the ramp.  Under those piles of nicely stowed yellow lines there are 12” stainless bow cleats, heavy bridle padeyes are installed down by the bootstripe line these days.
  • Score: Be kind, I have a thin skin.

So, what goes wrong with the design/build?

  1. Confusing priorities between design, marketing, and a business plan
  2. Weighting  “Cool” in the design mix ahead of function
  3. Thinking the International Standards just cramp your style
  4. Marketing beyond the initial design concept
  5. Judging “value” purely in terms of cost
  6. Believing utility is a tough sell and safety issues cramp your style

What should you do as a potential owner?

  1. Make sure the boat you are looking at has the stuff you really need for the voyages you intend to embark on.
  2. Keep your eyes wide open at boat shows, be critical, it really does matter.  If you trip, or your heel slides off an edge or you have to clamber over something at the boat show, imagine yourself at sea, in the dark, with a force  5 blowing, on a lee shore, etc.
  3. If you are hesitant to walk out on a trampoline, in spite of the salesman’s assurances, consider that your instincts could be sending you the real and correct message.
  4. Don’t put absolute trust in any bureaucracy to look out for your interests.  International standards organizations and their agencies must address a wide diversity of vessel types and some vested interests.  Occasionally meeting a rule to the letter may not give you a better boat.  Use your own judgment.
  5. swooshDecide whether the “Swoosh” constitutes real value or future liability.
  6. Do some mental arithmetic and figure what percentage of the boat price reflects sales and marketing costs and what percentage represents real content.
  7. Image yourself in the middle of the Atlantic when contemplating how much you can save on a vessel purchase.
  8. Decide if you are part of a large boat buying crowd or specific about what you want and need; will a mass produced boat mesh with your sensibilities?  (“mesh”, ha, ha)
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