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Anke and I are building our next boat, and writing about it at Access to the net comes and goes, so I'll be writing in fits and spurts.

Please feel free to browse the archives, leave comments where you will and write, and I'll respond as I can.

Fair winds!

Dave and Anke
triloboats swirl gmail daughter com

Sunday, December 29, 2013

A Short Review of Traditional Sailing Box Barges (Scows)

Easy to improve on these lines... or is it?

A Short Review of Traditional Sailing Box Barges

Box Barges (Scows) aren't new kids on the block. After the log, dugout and raft... barge.

For most of that span, they've been rigged for sail. And not just until folks knew better. Right up into the last of the Age of Sail, outlasting the clippers.

Take a look at the picture of the barge-ketch, above. It's likely a Great Lakes boat from near the late 1800s or early 1900s. She likely hauled freight in competition with any number of Curvy Dogs serving the same ports. Not only did she hold her own, but a whole fleet of her sisters were thriving in the same waters.

But look at those lines! Her steep, knuckled entry and exit are close to poor as can be. And this in a day when quality wood and skilled labor were in relative abundance. 

An abrupt entry means plowing water. An abrupt exit means a turbulent (draggy) release.

The economic advantages she gains through simple construction and maximum capacity on given footprint must have been enormous to outweigh making the slightest concession to speed! Hullwise, anyway... that rig looks speedy to me!

Still, if you ask me, those knuckled ends strike me as hard or harder to build than curves. And they wouldn't give up that much displacement. And with that bowsprit, lengthwise port costs couldn't have been a huge factor.

So it's a bit of a mystery that they built them so abrupt. Did they need to make the most of the deadflat for, say, stowing lumber?

ALMA, getting slipperier.

Here's ALMA, a San Fransisco Bay Hay Scow. Similar coasters carried Russian ice cut from Swan Lake, New Archangel (now Sitka, Alaska) to SF... no small feat, today... that's still one rugged coast!

 Lines are getting easier (longer and less abrupt)... more bottom curve and angle at both ends. 

We note that the exit is easier than the entry. Curious. Is this an evolved, hydrodynamically efficient arrangement? Or is it some holdover from the old (discredited) cod's head / mackerel's tail rule-of-thumb?

Let's establish a convention for talking about the proportions of aft curve : deadflat : fwd curve... looking at ALMA, I'm going to guess about 1/4 : 5/8  : 1/8 of LOD (Length On Deck).

Civil War era blockade runner
(replica built by Crystal River Boat Builders)
Here's one built to run wartime blockades... in other words, didn't want to be loitering around. I'll assume she wasn't slow, nor does she look it.

But she was also running supplies to ravenous armies, and likely slipping up sloughs and creeks to get out of sight. Of course she's a scow!

Proportions look to be about 1/3 : 1/3 : 1/3 (see also other pics of SPIRIT on related sites).

For the first time, we see an easy entry. Did this contribute to speed?

ANNA, looking sleek!
ANNA is another who's sisters were born in the Great Lakes. No plodder, she, though... This type had a reputation for speed among fast boats.

ANNA looks to be about 1/2 : 1/4 : 1/4... hard to tell... her aft curve is so long and easy that it could be anywhere from 1/3 to 1/2?

Here again, the entry is more abrupt than the exit, though it didn't seem to tarnish her reputation. 


So the question remains... is the blunt-ish bow fast enough to make no never-mind? Is the easy exit and release the real key to increased speed? Or is it an artifact of having aft cockpit and quarters aft, rather than heavy cargo? Or both?

Fortunately, we see 'good enough' anywhere in the range. 

My guess is that a moderate curve forward gives good performance, rises well to waves and pounds less in most conditions, while an easy exit lets the hull pick up and go. Other considerations can push or pull the shape this way or that without undue penalty.


An interesting aspect of traditional boats is that they were seldom designed, per se, but rather evolved.  Any more efficient variant, relative to the job at hand, tended to get copied.

Today, we tend to think in terms of speed or windward ability as the prime criteria for comparisons. But historically, at least among working craft, economy was paramount.

And economy is a gestalt of factors.

Even our first example was economical. We may no longer remember the reasons, but those who built and worked those pug-nosed vessels likely knew to the penny where profit lay and where not.

And that gestalt doesn't begin and end with the vessel itself, nor even its interactions with wind and sea. It perfectly reflects the state of supply and demand of its time; personnel, materials, cargoes, markets, competitors... even laws and the ability to enforce them. Of course speed and windward ability factor in, but they don't always have the only, or even the last say.

Our own lives have their own economic considerations. We want the best return on our investment, but 'best' is a fuzzy, nebulous, personal affair. And we're often led to look where our best interests are not, by those who would sell us a load.

We and the vessel we choose - if the relationship is to be a happy one - must also find economic balance.

Sunday, December 22, 2013

Box Barge Displacement: Archimedes 101

Plimsoll Lines from the Wider World of Displacement
 Box Barge Displacement: Archimedes 101

Story goes that, as Archimedes eased himself into his bath, the water he displaced ran over the edges and onto the floor. 

Nothing but a mess, for most of us, but Archimedes made a sudden connection; he knew, of course, that the volume of water he displaced was equal to his own, immersed volume. But what was not so obvious; The weight of the water he displaced must equal the weight of his entire self... specs, toupe, false teeth and all!

He got so excited by his discovery that he ran down the streets of Syracuse, buck-nekkid, shouting Eureka!!! Must have been somethin'... we're still talking about it 2000+ years later!

The actual Archimedes principle goes on to state that the floaty force acting on a floating object is equal to the weight of the displaced fluid.

So why do we care?

Well, we live aboard floaty objects. We want to know how much they can carry; how deep their hulls reach into the water; how much freeboard will stick out; how much it will settle if we move our anvil collection aboard; how much sail it takes to drive them; how they will float on their sides or upside-down. These and many other questions are informed by calculating displacement.

It involves a wee bit of math (Eeeeek!), but don't be frightened!!  Curvy Dogs require elaborate calculus, but we - box bargers - need only simple 'rithmetic. [Niener!]

The gist is that we want to convert our underwater (immersed) shape into a simple slab, whose volume is easy to work out. Being square sectioned (slab-sided), and rectilinear in plan view, box barges are already half-way there! One cheap trick is all we need.

Here's a walk through: 

Cheap Trick is close enough for Jazz... 
What we're doing, here, is combining the two wedgy slices at the ends into a single slablet, and adding that to the middle slab over the deadflat. We don't really need to flip one, as seen in step three... it's enough to understand that this is, in effect what we're about.

NOTE: Due to plywood standard dimensions, TriloBoat math is a snap in the Imperial System (feet, inches, eighths and pounds). The following can be done in Metric, but sadly, generates funny numbers and mistakes. So we console ourselves with a pint and work in the yoke of vanished Empire.

A, B and C are all linear distances between points along the waterline. Beam, Draft and Total are dimensional distances (at right angles to one another). When we multiply these together, we end up with Volume in cubic feet (ft3).

Once we have Volume, we multiply it by the weight of water in pounds per cubic foot (lbs/ft3). 

Fresh water weighs about 62.4lbs/ft3. Sea(salt)water is heavier at about 64.3lbs/ft3. A designer would choose one or another based on where the boat is expected to be used. It's not a huge difference, but does add up. The upshot is that the boat will float a little higher in saltwater. [Figures like these can be found in the Pocket Ref or searched for on-line.]

Displacement = Volume x Weight.of.Water / ft3

That's the general picture. Let's try an example from my point of view as designer:

Let's say I draw out a T32x8 on graph paper, for use in salt water. I decide that the draft will be 1ft and draw that in. Next I count squares along the water line, and find that:

A = 5.5ft, B = 16ft and C = 5ft

Total = (A+B)/2 + C
         = (5.5ft+5ft)/2 + 16ft
         = (10.5ft)/2 +16ft
         = 5.25ft  + 16ft
         = 21.25ft

Tell ya the truth, if the ends are this similar (which they usually are in TriloBoats), I'll cheat again and just call the wedges equal, and therefore A and C are too. Since they're the same, we don't have to average them; C simply completes A.So the above simplifies even further:

A = 5ft and B = 16ft
Total = A + B
         = 5ft + 16ft
         = 21ft

The difference between them only rounds a skosh downwards; ultimately, a bit of extra displacement is a pleasant surprise.


Volume = Beam x Draft x Total
              = 8ft x 1ft x 21ft
              = 168ft3

And (I reach for my calculator):

Displacement = Volume Weight.of.Water / 1ft3
                         = 172 ft3 x 64.3lbs / 1ft3
                         =  10802.4 lbs                         ... notice that the ft3s cancel out.


This boat displaces about 10800lbs. That is, by Archimedes Principle, how much she'll weigh, fully loaded, including the boat itself, gear, supplies, crew and the dog, when loaded to her Design Water Line (DWL) - the waterline as intended by the designer.

But lo! In the course of time, we tend to accumulate stuff, and each gimcrack and doohickey settles us a little deeper in the water.

For extra credit, let's calculate a displacement related number, Pounds Per Inch of immersion (PPI... somebody, somewhere dropped 'I' for Immersion!). This number is the amount of weight required to lower the vessel one inch deeper in the water. 

Here's the formula for our 32ft box barge:

PPI = DWL x Beam x (1in x 1ft/12in) x Weight.of.Water/ft3

That odd bit in parenthesis is a ratio, which merely converts inch units to foot units (one inch being 1/12th of a linear foot, or about 0.833ft). In our example:

PPI = 26ft x 8ft x 1in x (1ft/12in) x 64.3lbs/1ft3
       = 26ft x 0.833ft x 64.3lbs/1ft3
       = 1392lbs

That's a lot of seashells!

Note: Box barges with high ends load gracefully with weight secured low in the hull. But there are limits, and exceeding them can be deadly. Be aware of them! If in doubt, the Coast Guard is happy to conduct free stability tests for your design or boat.


Saturday, November 30, 2013

Heat Sinks, Hope Rises

COP (Coefficient of Performance) = Q (Energy Ouput) / P (Power Input)

Heat Sinks, Hope Rises

One winter, chillin' in Sitka Harbors, we noticed one boat that was pumping water, 24/7.

Normally this is a bad sign.  Bilge pump on. Leak. Problems. So we flagged down a Harbor Dude, and wondered if he might not want to contact the owner.

"Oh, yeah", he said, "it's not a bilge pump. He's got some kinda heater going."

Heater??? OMG, it's gotta be a heat pump!!! I started to salivate and haven't stopped.

Later, I ran into the owner on a 20degF day. He confirmed that it was indeed "some kinda heat pump", and that it was keeping his boat at about 60degF. "The equivalent", he said, "of a 1500W heater." (!!!)

So here's the deal. Any mass above 0degKELVIN is a heat sink, seething with kinetic energy. Gaian (liquid) water temps on pelagic-scale heat sinks means there are boatloads of energy out there to 'harvest'.

The notion of extracting heat from a liquid that, should we jump in, might be freaking cold, is counter-intuitive (at least to me). In high school physics I struggled (in vain) against the notion that there is ample heat in a frozen lake to boil a pot of tea. But it's one of those weird and wonderful truths!

The source of this energy is the nuclear-fired Sun. No perpetual motion, folks... when the sun burns out, the free lunch counter is closed. Get over it. Energy is not being produced by the machine, merely extracted from an energy reservoir.

P is the amount of power (energy) invested to harvest  latent energy from the fields of the sea. Q is the amount of energy harvested.

This is analogous to eating a big breakfast and gassing up a chainsaw (P) to cut wood. Burning that wood (releasing its latent energy as Q) returns more heat than you'd get burning the food and gas direct. The food and gas are investments against the energy stored in harvested wood. The Coefficient of Performance (COP) of the whole operation is Q / P. The bigger the COP, the better.

Heat pumps aren't  magic, or even terribly exotic. 

Your 'fridge pumps heat from the masses in its interior, and exhausts heat into its environment. Interior and environment are always tending toward equilibrium (insulation impedes this tendency). Heat pumps use energy to temporarily overpower this tendency. 

Ditto a heat sink.

Heat may be pumped to or from a sink. Air conditioners pump heat from the inside of your home and exhaust it in the atmospheric heat sink. And we actually rely upon oceanic heat sinks for our very lives. No other known planet has open, liquid water on its surface. Think about it!

Commercially available units are 'air conditioners', primarily designed to cool cabin spaces:

Pump seawater in.
Raise it's temperature a few degrees using heat drawn from the boat's interior.
Pump seawater out, warming the environment (heat to heat sink).

Some (the ones that have me a'drool) have a reverse cycle, functioning as a heater:

Pump seawater in.
Lower it's temperature a few degrees, diverting that energy into the interior.
Pump seawater out, cooling the environment (heat from heat sink).

P runs the water pump, the heat pump (which raises or lowers water temperature, using refrigerant gas/fluids for the transfer) and a fan to circulate conditioned air.

Q is the thermal energy transferred to or from the water.

Mind your Ps and Qs... in other words, convert them to common units (Watts is convenient).

COP, or Q / P is a ratio (no units, since they cancel out), which currently approaches three... for every unit of energy invested, we harvest about three units. We could say Q = 3P. Our net gain is about 2P (we double our investment). As any banker will tell you, that's pretty good return!


One small, commercial unit made by WEBASTO is rated at 5000BTU/hr, pulling 4.4A on 115V. That translates to P = 506W/hr, Q = 1465W/hr, COP = 2.89 and change.

Downsides are, these units are large, spendy and not at all KISS. Those ratings are set for some supposed-to-be-average condition. For those of us who sail in below-average conditions, performance falls. The power draw is high enough to be prohibitive for cruisers off-the-grid.

Still, 'tis early in the game, and technologies are advancing which could lower P and raise Q, increasing COP. Costs should fall with market penetration and economies of scale.

In the near future, I would love to see some of Q converted to electricity and fed back into P... once kick-started, it could run on harvested energy (with correspondingly lower COP). Since the sink is virtually unlimited, there would be no  limit to the system size (aside from practical considerations such as cost and footprint). When not being used as a cooler/heater, it would be in essence a generator.

Hope rises!

NOTE: If our WEBASTO example, once up and running, converted heat to electricity (assuming 100% efficiency), then Q = Q-P, or 959W/hr, free and clear. This could go to heat, charging or output power nearly equivalent to a 1K generator. Inefficiencies will gobble some of this up, but it's better than a kick in the head!

A large-scale implementation is now working at the Marine Science Institute in Juneau, Alaska, The heat it supplies replaces 60,000 gallons of fuel per year! Click here to check it out!

Alaska has other projects underway and online around the state. If we can do it here...

Monday, November 25, 2013


                                And I'd add "Every WOMAN, too!"

                          Logo from Hobo and Sailor Design


One of the formative influences in my life was the Whole Earth Catalog. It embodies the Hippie paradigm with which I've identified my whole, so-called adult life. And within that fascinating work, what drew me especially - over and over again - was the section entitled Nomadics.

To me, its every page breathed freedom. And not just freedom, but romance. The Road! The Horizon!! Oh, how they called to my institutionalized soul, my eyes bound round by looming apparition of civic duty (Vietnam) and career. On bikes and boats (writ small in my awareness, as yet), in buses, in tents and afoot, my generation was going walkabout!

Nomadics. Apparently the word speaks for itself. When I went in search of a toothsome definition, I came up empty handed! WHAT?? Dictionary, no. Online, I got the usual zillion hits, but no definition! Nomad and nomadic, of course, but not nomadics.

So I'd better take a stab at it:

nomadics, /no -MAD-iks/ Plural noun [usuually treated as singular] The art, science and study of nomadism and related skills and technologies.

Well, the war ended before I came of age, and I felt all the conflicted relief of one who would have gone, but was not called.

So I went career bound via college on a full financial ride for po' boys from small ponds. But it had a quirky catch upon which my fortunes turned: any money I earned in summer went directly to the school. That meant all my summer expenses - food, rent, utilities, and everything else - became debt.

What to do? Well, I'd never seen much of America outside of SE Alaska. I stuck out my thumb and hit the Road, bartering work for rides and food.

I loved it - the US, Canada and the Road! Three summers adrift,  breathing in the glorious vistas of the New World, meeting unimaginable characters and forging, with them, a fireside philosophy of Nomadics.

But the glow of the sixties was fading. It was the early 1980s, and the country had turned sharply to the right. The ideals of peace, love and tolerance; living lightly in harmony with the earth; the rejection of the military-industrial complex were marginalized, spun and commodified into oblivia.

 [I know, I know... but they were ideals, and for all the flaws, they inspired and motivated a generation.]

They were being supplanted by a hard-edged reembracement of wealth and power; a 'rugged individualism' that read 'you're on your own, Jack and Jill'; and intolorance fired by a style of Christianity deaf to the words and example of Jesus. One of the early consequences was widespread rousting of the mentally ill from institutions.

The practical effect on the Road was that, in three short years, word of hitchhikers who'd been assaulted went from rare to nearly ubiquitous. Unstable persons with psychological problems are hard to distinguish from 'ordinary' wanderers. Nomads were no longer seen, in the main, as interesting travelers, willing to exchange value for value, but as vulnerable ne'er-do-wells somehow asking for trouble. And as always, when such a mindset takes hold, the real ne'er-do-wells act that mindset out.

The Road had become positively dangerous.

Well, I was now 'my own man', free to decide the course of my life. Careers looked bleak and pointless to me. I was working, sporadicallly - contract jobs as a computer consultant covered expenses without demanding much of my time. Interesting, but unfulfilling.

The Road still appealed... a vehicle of some sort? But vehicular vagrants were no more welcome than other mobile homeless and stick out all the more. Cars, vans and buses are expensive, tied to the oil economy and confined to roads. Not to mention the shabby, polluting, wasteful nature of it all. At least hitching, I felt I was increasing the per capita efficiency of the vehicle [how lame is that??].

One day at the library, going through free boxes of books being purged from their shelves, I came across Ken Neumeyer's Sailing the Farm: A Survival Guide to Homesteading on the Ocean! I stood there, trembling, the book in my hands, as connections met and fused. Just reading the cover had precipitated my moment of satori!

My life had circled back round to Nomadics. The art, the science, the skills; shared with us by our mentors and comrades. 

That's what I write, here. That's what I hope to share and encourage, paying down the debt.

With gratitude and humility, and the knowledge of what might have been.

Sunday, November 17, 2013

Sitting Quietly

Photo Credit Mark Zeiger

Sitting quietly,
doing nothing,
spring comes
and the grass
grows by itself.

Zen Saying

Sitting Quietly, Doing Nothing
I love rolling along under a fair wind. I love working our way against wind or tide. I love nosing into intricate, rocky labyrinths. I love being under way.

But as much or more, I love lying to anchor. For days. For weeks. For months. In some quiet pond, far from the threat of storm. Embraced by stone and soil and the deep, dark trees.

We bluster in, under sail or yuloh a-swash, command and answer-back disturbing the peace.

Stand-by the port anchor (Standing by, port anchor)! Let go the anchor (Anchor's away... SPLASH)! Anchor's on the bottom (On the bottom, aye!)! Make fast (Making fast)! DOINK! Dropping foresail! Whack-ack-ack-ack-huff! Drop the mizzen.. Overhaul the sheets. Raise the rudder and stow the boards. CLUNK, boom (wheeze)!

Our clamor stills, embarrassed by silence.

A bruised silence that holds its breath, waiting... so silent our very breath rasps at it. Our pulse resounds in combers of blood.

But then, the cautious peep of a wary bird. A beat. Another trills in answer. Water, its exact position as yet unknown, resumes its flow, chuckling to itself at the audacity of strangers.

Silence gives way to mere quiet.

And we sit a while and drink it in, speaking, if at all, in murmurs. A glass of wine to honor the setting sun; to ease the strain of muscle and mind that brought us to this place.

We watch those who live here return to their business. Shy at first, but emboldened by our lassitude, they sport and hunt and hide and run from danger – seizing their days and cracking the bones for the marrow. Caught up, one and all, in the same drama as we.

Later to bed and the pleasures thereof.

In the days to follow a book or three. Music made by hand or accepted as the gift of others. Dreams projected in pencil, spilling over the page. Idle banter or none. Caught up in ourselves, or reaching our thoughts to you, our friends, one by one.

Out and about, we come to know the surrounds. Which plants grow, and where. Who made which path, which hole, which midden.

And weaving through it all, the  wood gathered, fires kindled and meals shared. Companionship and content in every chore, in every joy.

Sitting quietly, doing nothing, our lives, like the grass, grow of themselves.

Saturday, November 9, 2013

Mast Overboard!

Scene o' the Crime

Now the LIZA JANE got a new foretruck,
Good stick o' wood but it wouldn't stay stuck -
Got a breeze one day from the nor'northwest
Doggone thing come down with the rest.
Hi diddle di and a breeze from the west
You'd a' thunk the truck wouldn't stuck with the rest.

  -From words attributed to J.B. Connolly by Gordon Bok, 

      who put them to music as LIZA JANE

If ants were called elephants,
  and elephants ants,
  an elephant!
   -- Danny Kaye


In a previous post (this one), I recounted the tale of our first dismasting which I attributed to a willawaw (micro-burst of wind), under-sized mast and low quality wood (widely spaced annular rings). We've now doubled our 'experience' in this regard, but with none of the excuses.

We'd been visiting my Brother's family in Northern Lynn canal, and it was time to head south. It had been blowing SE6 (of course) for weeks. We can claw against that, but it's slow, uncomfortable going. [Here's a great graphical chart of the Beaufort Scale for wind strength.]

But that day, it was forecast to drop to SE4, and we make pretty good time in that.

So we set out with the tide, about an hour before dawn, pulling our two anchors and beating out in flukey, gusty wind. We could tell by white-capped waves that the forecast was understated... here, at least, it was back up to SE6. 

We were doing well, however, and hoped that, once we cleared the Chilkat Peninsula it'd drop down (S winds get squeezed, N of that point). If not, there are anchorages in the Chilkat Islands off its tip.

By first light, we'd cleared our little bay, and were tacking across the tip of the minor peninsula that forms it.

A bit of a gust, and, without much ado, our foremast and sail calmly take a jump to the right and overboard!

What, again???

Quick assessment: Canted into the wind on the port tack, held up by our mizzen. The blunt end of the peninsula is a lee shore. Ranges show we're don't have a chance to clear back into the Bay. 

We back rudder and mizzen, attempting to 'tack', but no go... too much drag to bring the bow across the wind. Anchoring may be possible, but it's deep, here, and by the time it shoals up, it will be our last option.

Okay. If Mohammed won't go to the mountain... 

We're free-standing junk rig, which means the sails can be run forward of the beam. And a barge looks pretty much the same, one end and the other.

So we declare a proa-like reversal - the bow is now aft and the stern forward (ants are now elaphants).  

We fix a dock line to the end of the mizzen boom, and lead it aft. Sheet in, reverse steering from the bow on s'brd tack, slightly broad of a beam reach. Check ranges? Clearing!

Once clear of land, we anchor altong shore on the Lynn Canal side and haul the sails and mast aboard. This was challenging, as they'd spent a while, tossed and tangled in the waves. But we managed.

Next trick-in-a-row was to get ourselves into a lee. The next reasonable choice was Portage Bay (Haines), about eight miles north. Without the drag of the mast and sail, we were able to steer the (true) bow off, so we squared away and ran off under the mizzen alone - more or less like normal folks.

NOTE: Sailing off with an after sail gives about 90deg of solid freedom, from broad reach to broad reach. Some hulls can come up even higher, even to a beam reach... but this can depend on wind and sea state.

By afternoon we'd arrived, anchored, shortened the mast and rerigged. Beer-thirty at the most excellent Haines Brewing Company!


What did we learn, this time?

The autopsy showed that onset rot had made deep intrusions into one side, along big stretches of its length. Oddly, none of this showed (usually the edges of longitudinal stress cracks start first), nor sounded (when thumped like a watermelon). 

The areas with rot were still pretty solid, just robbed of strength. Maybe that's why I couldn't hear it? Or maybe I need to better train my ear!

We had felled this tree for Andy Stoner's MARY ELIZABETH a mere eight years earlier (already??). It never got installed, but sat on the dock, waiting. When the Harbor folk wanted it out of there, Andy offered it to us and we jumped at the chance. But top down, fresh water had taken its toll.

LESSON: Make sure that lumber has been well-treated... take its full history into consideration.

Another point is that Anke and I have used a rule-of-thumb for when to reef, being when the leeboard guard goes awash (about 15deg). We're reassessing this, however, especially in gusty weather. And especially given the... ah... funky nature of our trip.

A big virtue of the box barge is its extremely high form stability. It resists heeling in direct proportion to heeling moment. But all that force has to go somewhere. It is distributed around the boat and rig. In a free standing rig, a good dollop accumulates just above the mast partners (in our case, the tabernacle hinges). This is just where both breaks have occurred. 

LESSON: Reef a little earlier, Simpletons! The whole point of junk rig is to make that easy!


We found a beautiful, new mast, and she's withstood her sea-trials in blustery autumnal gales. We've rescheduled the mizzen for early replacement, and are considering up-grading to foremast size. That would allow exchanging, should it ever become necessary (knock on sound wood!). And we're thinking about running backstays for tough going. Can't hurt.

So we sail on, a little delayed but wiser.

PS. Anke thinks the Ants/Elephants allusion is typically opaque and unnecessary. I love it as an early prod toward thinking out of the box... reframe the problem and squash it (not that I want to squash any elephants!).

Monday, November 4, 2013

Looking at Barge Bottom Rocker

Is you a Gazelle?

Or is you a Elephant?

Looking at Barge Bottom-Rocker

One of the distinguishing features of a box barge or scow is a large-ish mid-section deadflat.

By deadflat, we mean flat both athwartships and longitudinally. Another way to say this is that the mid-section has zero rocker. Rocker is bottom curvature as seen in profile, like looking at the bottom of a rocking chair from the side.

When bottom rocker is discussed, it's often asserted that a rockered bottom is faster (more easily driven) than a flat one. In respect to barges, I once read (somewhere) that even a little rocker improves speed.

In Triloboats, I specify deadflats without rocker. 

The primary reason for this has been ease of construction. 

Over the deadflat, everything is four square. The bottom edges of furnishings or structural components don't need to be shaped to fit a curve. Standard house cabinetry or furnishings could be simply fixed in place. As a bonus, during construction, the deadflat is like a very large workbench for building such bits and pieces as bulkheads, transoms, decks, etc.. These considerations, however, fade in your wake, once the boat is built.

A secondary(?) reason is that cutting away from sides of given height and draft also cuts away from interior volume and displacement. In optimized sheet construction, cuts always reduce these values, relative to what's made possible by the materials. To regain volume and displacement, one would have to increase side height (presumably to the next efficient sheet fraction) and cut away from that, and/or increase draft to make up the amount of displacement lost to rocker.

Adding a little rocker - breathing 'life' into the deadflat - is entirely possible, but takes time and a little skill (not much). But the benefits, if any, would last the life of the boat.

But are there benefits?

Well, I tried to hunt down some evidence for the assertion that rockered bottoms are faster, especially with reference to barge hulls. What I found surprised me.  

Here's a sample, typical of what appear to be informed opinions, this one from the world of surf-boards (highly developed 'hulls' of similar footprint, lots of feedback, with many designers being also expert boarders... I omit the caveats about the complexity of the subject):

Some basic 'rules' concerning rocker are as follows: The more rocker or bottom curve that a board has, the looser (but slower) it will be. Water flow has to follow the excess curve, ends up pushing water, and drag is the result. Flatter rocker brings more speed but brings a decrease in maneuverability. Generally, boards with more rocker work better in larger, hollow waves where the added curve and drag can contribute to more control for the rider. Flatter bottoms are normally used on small-wave boards designed for slower, mushier surf, where the speed (and added leverage) help keep the board planing.

As with every other aspect of surfboard design, the best option lies in the happy medium of compromise. The better-designed surfboard steers clear of extremes and finds that an even, neutral rocker serves best: flat enough to be fast and efficient, but with enough curve to let the surfboard fit into the curved face of the wave and allow for the tight turns that are the mainstay of performance surfing.
 -- Dave Parmenter

Key points that emerge are that the question is complex; that more rocker equals more maneuverability; that less rocker is faster... less draggy! 

NOTE: For our purposes, fitting to curved wave faces and tight turns are negligable. I include them to contrast flat and fast vs. rockered and draggy/maneuverable. Among all the practicing sources I found, these associations appear standard (I specifically exclude forum discussions).

CAUTION: Astute reader Glenn (see discussion in comments) correctly points out that surfboards - being planing hulls - aren't relevant to displacement hull design (Barges, among others). 

He further writes: " In a displacement boat the smoother you make the transition between midships and the aft waterline, the better. The more abrupt the run, and the more immersed the transom, the more drag on a displacement hull. Period." Rocker, whether it be full length or partial (between more abrupt end curves), will ease this transition, and, if this be true (likely), reduce drag. 

In other words, some of my conclusions are at best suspect. Even more so than usual, that is! 8)

RE maneuverablilty -- This agrees with our experience on LUNA (fully rockered, Advanced Sharpie), who could turn on a dime. SLACKTIDE (deadflat, box barge) has a wider turning radius, but not bad. Turns on a nickle? Both have high aspect ratio lateral resistance devices (leeboardy off-centerboards) and big rudders, which I'm guessing play more of a role than mid-bottom profile in shoal boats.

RE speed -- In practice, I doubt one could tell a difference in real world situations. Both LUNA and SLACKTIDE get to hull speed, and it doesn't take a fair gale to do it. Meanwhile a lot of other factors weigh in... size of boat,  end curve placement and heights (for another post), ballast and loading, sail area and shape, sea state (bucket o' worms, right there!), angle of heel and course to waves and so on.

RE grounding -- Generally, a rockered bottom is stiffer, all else being equal, than a deadflat. Even if the deadflat has supporting structures (e.g., vertical faces of furnishings), these break the large deadflat into smaller ones, each of which will flex a little more than if they were rockered.

Grounding on rockered 'belly' concentrates the weight of the boat on a relatively narrow, thwartships band running across the point of deepest draft. In LUNA (aggressively rockered) this was an area between one and two feet by eight feet (depending on how yielding the ground). Grounding on SLACKTIDE's deadflat, the boat's weight is spread out, much like an elephant's foot.

Question is, is you a gazelle or is you a elephant?

Actually, I don't think this matters much, either. I've seen hulls of both types and similar scantlings (structural dimensions) do fine, grounding on reasonable bottom. 

Nevertheless, I personally incline to the deadflat here, too.

If one settles onto a sharp rock, PSI (Pounds per Square Inch) skyrockets at its tip. Focused PSI like this is what allows a thin, pointy nail to be driven into hardwood. Fortunately, considerable hull weight is supported by whatever other part of the bottom settles down, relieving some load on the rock. But still.

This is usually happens in a triangular pattern... the rock forms the apex of the triangle, while the baseline, opposite, relieves  load. The baseline could either be an opposite chine, or a thwartships area toward one end, depending on where the rock contacts the bottom (picture the rock like a jack lifting the hull from the ground... around what line will the hull rotate as the jack lifts?).

In a rockered bottom, worst case scenario is a very short baseline (the low point of one chine or the other). A deadflat puts down a long baseline (the chine along one side of the deadflat). It's 'worst' case (settling onto thwartships band) is the rockered bottom's best case.

However, in both LUNA and SLACKTIDE, what slight bottom damage we've suffered had nothing to do with shape, but rather, concentrated PSI's locally exceeding the crush strength of our (copper plated) plywood bottom. Makes a divot.


So. My state-of-the-art preference (where barges are concerned) is for the deadflat... not just as a worthwhile compromise, but as all-round winner. See CAUTION, above.

PS... When rolling LUNA, one annoying habit emerged. It's uphill and down over rollers, and her belly tends to bottom out very shortly between rollers. SLACKTIDE's deadflat makes rollering a piece o' cake!

Barge Come Ploddin'

Classic Barge in NYC (

Long hours at the helm or scull give one a lot of time to sing, with none but the gulls to hear.

And, if one is sailing or sculling a barge, songs that have something to do with them are extra fun!

The barge repertoire is kinda limited, however. Lessee...

Lotta barges on the Erie Canal... even a song of that name (by the great Springsteen Hisself!). The E-R-I-O was a'Risin' is a rockin' tune, heading up a mixed list of barge-based songs of inebriation. Shawnee Town, by Chris Vallillo is a beaut from the O-hi-O.

Then there's Barges, a deceptively cutsie Girl Scout camp song. [CAUTION: It's an earworm that's hard to kill!] Or the beautiful but mysterious Barge Song  by Malkah Duprix. Even Denis Leary gets on board with Love Barge.  8)

Or the classic chantey of the Volga Barge Haulers, aka 'boatmen' (check out the Glenn Miller version of '41... I presume it topped the charts after Hitler invaded the USSR in June of that year???).

Or -- if you squint -- Gordon Bok's Liza Jane or Old Fat Boat... they could be about barges. Or not. [CAUTION: To hear these, you may have to quickly squelch the ad-blast for Euro-Barge by the Vandals. Or not!]

Somewhere out there is even the Star Wars soundtrack for Jabba the Hutt's Barge!


Alright. A good handful, but none of these exactly celebrate the barge itself. So I  whipped up a ditty to fill the gap. Hopefully y'all are as tolerant as the gulls!

Note: I apologize for any formatting errors some of you may see below... the art of WYSIWYG is in sad decline. If you have to copy it out, all the vertical bars should align.

Barge Come Ploddin' 
Words by Dave Zeiger PUBLIC DOMAIN 2013
Tune of
John Johanna (JOHN JOHANNA), traditional... repeat 3rd and 4th phrase for chorus... Slow and easy, or fast an fierce... Bars indicate the first downbeat of each line. If you're brave, you can hear me slaughter it here.

                       Am                      C
                     | First Boat was a log, you know;
                       C                               Am
                     | Second come the raft.
                       Am                          C
                     | Next Boat was a Barge, my Friends;
                 A | most persistent craft!
                     | Hulls that shaped the Age of Sail
                       C                            Am
          Have | all but passed a-way;
                       Am                         C
      But the | humble Barge is out there;
                       C                             Am
         She's | haulin' freight to-day.

CHORUS:         | Who that on the water,
                                C                                       Am

           When the | others done been and gone?
                                Am                       C

                              |Takin' her time, haulin' her load,
                                C                     Am
                              | Barge come ploddin' along!

                | Some folks call her Barge, my Friends;
                | Some might name her Scow.
                | Sometimes goes by other names;
                | It don't matter nohow.
                | Sailin' down the river,                          (| up)
          Or | up along the coast                                (| down ... shore)   
                | Haulin' her load on big, wide feet

    Come | wind nor rain nor frost.               (And | comin' round for more)

[May repeat this verse, with alternate words to end song.]

                | Sailin' in deep water;

                | Skimmin' o'er the shoals;
                | Takin' the ground as a matter of course,
                | Neapin' out the blows.
                | Cheap to build, cheap to run,
                | Born to haul car-go.
    She'll | stretch that Almighty Dollar
 Just as | far as it'll go!

          So | let that yachty feller
          A-  | lookin' down his nose
                | Talk o' spit and polish

And the | Beauty of a Rose.
       Just | smile and nod and wink yer eye;
                | Let him have his say.
       And | when that tide come a'risin'...

   HOIST | SAIL and slip away!

[May repeat second verse, with alternate words to end song.]


So there ya go.

If any of you with the skills care to put together a track to spread around the public domain, please give it a go! Send me a link and I'll post it here. 

Ditto if you know of any more barge songs.

Let's hum a few bar(ge)s!

Saturday, October 26, 2013


The Dream...

The Vermont Sail Freight Project Reality!

 In the end all was fine, our fine barge rose to each challenge gloriously.  Captain Steve, who had been dubious about the seaworthiness of the barge right from the start was ready to hug me and declare me a master shipbuilder by the time we had rounded the battery. 

From Ceres has Arrived in NYC by Erik Andrus

In the brief time since my last post - SPLASH! CERES Launches the Vermont Sail Freight Project - much has happened.

First, she goes and attempts a late-season maiden voyage / test cargo run from here homeport of Vergennes, Vermont, across Lake Champlaign to Burlington. Full success.

Okay... that was ambitious. New boat with all the small details to work out. Challenge enough. But a cargo of foodstuffs to organize, load, transport, unload and market? Well... if you can do it, it ain't braggin'.

Time to put her to bed for the winter, right? Right?? Ruminate and plan for another, modest step forward come spring?

Next I check in, she'd acquired Captain Steve (Schwartz) "who has a pedigree of experience with traditional sail on the Hudson River going back to the inspired zaniness of the early days of Pete Seeger’s sloops, the Clearwater and the Woody Guthrie. Steve has been involved with skippering the latter for many years."

Note: All quotations from Erik Andrus (Designer and Builder of CERES) who is enscribing her adventures at

Then straight-away, she headed off down the Hudson River, in October, loaded to her lines with several tons of cargo, worth thousands (the very livelihood of local Vermont farmers who comprise the Project)!

I mean, do these guys have cojones, or what???

'Course, I missed all that. By the time I next get connectivity... they have ARRIVED in the Big Apple!!!

No way! Nobody moves this fast! 

Started in May, launched in September, initial sea/commercial trial in September. And in October? MAJOR FULL ON VOYAGE WITH HOLDS STUFFED TO THE GILLS!! 

 I feel old.

And it's working! They are met with open arms in every port, wined and dined, and their cargo is selling like hotcakes all up and down the Hudson!

It is truly wondrous to see this project bloom. Aside from my obvious, bargey bias; to see the buzz and excitement enfolding this small step toward the New Age of Sail.

Well, I won't say more, other than to marvel at being able to witness the transformation of Erik's dreams and drawings into the very stuff of life. 

If we only dare...

Speaks for itself, dunnit?