Please visit our home site at www.TRILOBOATS.com.

Anke and I are building our next boat, and writing about it at ABargeInTheMaking.blogspot.com. 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

Thursday, April 12, 2018

A Look at Box Barge/Scow Sailing

SLACKTIDE sailing to windward in about 20 knots of wind.
For some reason, the fairly extensive white caps didn't show up,
and I apologize for the wind-in-mike effect.


If a pitcha's worth a thousand words, how much fer a movin' pitcha?


A Look at Box Barge/Scow Sailing

If one were to go looking for some video of cruising-sized, box-barge/scows under sail... well... it's thin pickin's.

Despite the fact that sailing barges and scows once carried a good deal of freight in Europe and North America, very little information as to how they sail is readily accessible (okay... google, right?).  One can only infer that their numbers prove they must have been able to compete against curvy dog rivals.

We had extensively sailed LUNA, a fine sailing hull modeled on Phil Bolger's AS29. It's a square sharpie... much like a barge, but with ends pinched in. It's full rocker sets it off from the large, mid-ships deadflat that help keep Triloboats relatively quick and easy to build, and was a common feature of the sailing barge/scows of yore.

We reasoned that the barge/scow form couldn't lag too far behind. But as a precaution, we built SLACKTIDE as a proof-of-concept before committing to WAYWARD, a full-sized liveaboard cruiser. After all, sailing engineless in SE Alaska, ya need to be able to get out of yer own way!

To make a long story short, box barge/scows sail reasonably well. We've had no problems going anywhere we wish, and that involves many places and situations most wouldn't care to take their sailing home, no matter its capabilities.

Things I note about box barge/scow hulls:
  • Heeled, they present a V to the water.
  • Upright, their entry is rather fine (directing water downward for lift, rather than parting to either side... this is true even with relatively abrupt bow curve).
  • Easier aft curves release water well and make for an easier driven hull.
  • More abrupt forward curves don't seem to hurt, and do seem to reduce pounding.

The videos embedded here allow a look at how three models sail. Cast of Characters as follows:

SLACKTIDE (26x7x1) is a Triloboat Junk cat-Ketch with rather abrupt end-curves, intended to prioritize carrying capacity over speed.

SPIRIT (36x12x?ft) is a Civil War Cargo Scow gone Blockade Enforcer, with easy lines prioritizing speed.

ALMA (60x22x4 is a San Francisco Hay Scow Schooner. Her lines are quite abrupt with a long deadflat, prioritizing heavy lading.

So here ya go... a movin' pitcha look at box barges under sail:



SLACTKIDE running under reefed sails in confused seas


SLACKTIDE close-reaching in light air.



SV SPIRIT sailing on several points.
Note the view of the bow waterline... not much fuss.



This hull, compared to the others, is a relative pig to handle, 
yet comes about slow but sure.

14 comments:

  1. Thanks! They quicken the heart just a bit.

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  2. Hi Sixbears,

    Thump-a, thump-a! Us too! Can't wait to finish up and get some sailing in. Coupla more weeks!

    Dave Z

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  3. Replies
    1. Hi Shemaya,

      Glad you like!

      Hopefully we'll get some vid, soon of WAYWARD coming about. She tacks quickly and reliably (with half her length in deadflat).

      Dave Z

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  4. What a pig the Alma is coming about.... makes a case for some rocker. While in Florida about 2 years ago I sought out the Spirit and when no one was looking jumped aboard (no one aboard, of course) and walked about. What a beautifully lined vessel. Brings to mind visions of civil war blockade running on a new moon night blasting over shoals, cannon fire receding off in the void. VERY romantic vessel.

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    Replies
    1. Hi Robert,

      Increasing rocker (shortening deadflat) definitely makes a boat more nimble (quicker, coming about). As with all things, though, it trades one virtue for another. In ALMA's case, quick tacks were of lower value than her enormous load-hauling ability.

      Ditto her relatively low length-to-beam ratio of about 2.66 to 1 (as I recall). I prefer 4+:1, and consider 3:1 the lower end for box boats who want to sail in general conditions.

      And yes, S/V SPIRIT trades at the other end... less hauling but better sailing qualities.

      Comparing the two, I wonder if ALMA - whose sailing grounds are the Sacramento Delta and SF Bay, required less ability, while SPIRIT - sailing not just rivers but the open Florida coastlines - needed more?

      Both cases fascinate me as working vessels thriving in direct competition with Curvy Dogs.

      Dave Z

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    2. 5:1 sleekster, 12:1 trilo-proa. From viewing model testing of barge shapes it seems slight rocker might be worth it on a barge sailer. Take something like Loose Moose 39 and just open the ends to barge square shape and reduce rocker a bit and perhaps the best of both AS and Trilo worlds.

      Delete
    3. Hi Robert,

      I agree that slight rocker in place of a deadflat is something to consider. It certainly adds rigidity to the bottom, and may well result in an easier driven hull.

      The main advantage of a deadflat is simpler construction, mostly in matching vertical elements (sides, furnishings, bulkheads) to the curve. Not rocket science, but it adds time and material.

      The end curves are a significant departure from AS hulls, however. At both ends, squaring out to a rectangle in plan (top) view) means that the ends need to be carried higher to avoid plowing/dragging when heeled.

      A side benefit of a high, relatively abrupt bow curve is that it reduces pounding. The low AS bottom curve angle is easily reached by waves while sitting upright in an exposed anchorage. Like two hands clapping, a boom results. The higher barge ends only match wave angle in extreme conditions. Even then, the greater arc at the short ends quiets the whump.

      In our experience, AS pounding at anchor occured only rarely, when considerable wind came up in exposed anchorages. We have yet to hear steady pounding in the barges (no more than we've heard in Curvy Dogs). The bow is more 'talkative', but is more the cheery riffle of a small stream.

      Dave Z

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    4. Alma a pig? I would respectfully disagree with that sentiment. :)
      I actually thought she tacked rather well. Admittedly watching one tack on youtube isn't much of a test. She is a bit on the small side but to my eye she tacks like a good working schooner of that vintage, regardless of hull shape. I didn't see anything to complain about relative to the much curvier similarly rigged schooners I've put about.

      Thanks for the sweet videos, Dave!

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    5. Hi Bryce,

      Thanks for your respectful reminder that I need to show more respect! Especially as I feel it toward ALMA... I should avoid such casual and undeserved perjoratives as 'pig', even when speaking relatively.

      Thanks, too, for the input on how other schooners come about. I have so little exposure beyond the handful of boats we've sailed... good to know that not every boat out there is turn-on-a-dime.

      Another thought RE ALMA is that, as a landmark vessel, she's likely to be crewed largely by less experienced hands, overseen by more experienced 'officers'. Crisp tacks take time for a team to work out... I suspect all the moreso for larger vessels?

      I've always thought that a higher length-to-beam ratio must make for an easily driven, quick tacking hull. Curvy schooners tend toward a higher number... from what you have observed, maybe it's not as important as I've thought?

      Dave Z

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    6. Hi Dave,

      I actually have an embarrasingly hard time sailing a modern turn-on-a-dime boat. I've spent better than a decade sailing long-keeled vessels in the 120-190 foot range, and my small boat experience is limited to an 80 year old fixed keel Seabird yawl and a Wharram Tiki 26. I've sailed on the modern production monohulls of some friends and I'm always amazed at how they can spin on a dime, and at the interesting directions they go when you let go of the tiller. Everything is compromise, right? Personally I find the ability to step away from the tiller and not have the boat get squirrely absolutely worth taking a bit longer to tack.

      I think maybe you're being too hard on your boxy hulls relative to other boats. I'd heard a lot about how Wharrams were hard to tack, but when I got one I just had to sail her around like I would a big schooner, and she tacked beautifully. And I could let go of the tiller and she'd go pretty straight. Same with my 1930s era yawl. I suspect that your designs probably behave similarly?

      As far as tacking a big or un-nimble vessel, the method I've learned from a lot of good captains over the years is pretty straightforward:
      Bear away and gain speed before starting your tack.
      Don't stall the rudder, ever. Maintaining momentum is more important than trying to turn too fast. This will absolutely make or break a tack.
      Hold your headsails aback until you're all the way through and they're blowing you off onto your new course. (Obviously I haven't tried this with a junk rigged boat.)
      Shift your helm if you start making sternway; it's often possible to back through the tack if you have room.
      If you have sea room, gybe or wear ship instead - it's easier to do shorthanded, often faster, and if done with alacrity won't lose too much ground. Also you never lose steerage, which is nice.

      Teamwork is, as you say, critical. Patience is also a virture - I've seen more than a few really good modern sailors who lacked the patience to effectively tack a heavier, less-nimble vessel, and thus repeatedly missed tacks before they finally surrendered to the process and slowed down.

      My experience with higher beam-length ratios is that while they definitely make for a more easily driven hull, they don't make tacking faster at all on their own. Underbody profile has a much greater effect. At the extreme end, harbor tugs are designed to be quick turning (albeit under power, but they're still moving in water) and they seem to get shorter and wider and rounder every year. As far as sailing vessels go, the amount of fixed lateral resistance in the ends of a vessel probably has more to do with how quickly she tacks than anything else. As one example, a big (150 foot) sailing vessel was built similarly to an existing vessel, but with modificaions to her underbody so that she would tack more easily. When built, she did. However, she was less smooth to gybe, and you could no longer step away from the helm for 10 minutes at a time once her sail plan was balanced. In order to tack more quickly she gave up a lot of course stability. As sail training vessels neither ship was fitted with an autopilot of any sort. They're both wonderful vessels, just a little different.

      Thanks for putting up this wonderful blog. Don't think for a second that what you're doing isn't significant. I haven't come across too many folks really sailing hard in old-school vessels. I've learned a lot from your experimentation and your sharing of experience. You two are doing awesome stuff!

      Bryce

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    7. Thanks for the encouragement!

      I expect you're right re underwater profile being the biggest influence on tacking. A lot of the development of sailing yachts seems to have been to cut away from full keels at both ends until a mere sliver is left in most competitive cases.

      One of our fin-keeled friends said he used to fight to heave his boat to, with little success. Finally, in disgust, he simply let go the tiller. He said it sailed in erratic circles that tended to stay put. Once he quit minding, he said, no problem!

      In SLACKTIDE and WAYWARD, we very rarely miss tacks. Generally, we don't need to bear off (can be we're already sailing wider than is usueal) nor generally to back sail.

      If we do miss a tack, first option is to back rudder and mizzen, cock over (about half a boat-length) and then sail off... saves about 90% of missed tacks.

      For a miss in high winds and steep chop, we'll back the foresail far enough to trim for a 'close reach' about perpendicular to the centerline... this sails the bow around the backed rudder, and recovers from most anything.

      Oddly, wearing around has been a challenge for us... the shallow hull really takes off, and resists falling off at speed. Possibly from sheet friction in the mizzen? We end up making a huge, wild round. Probably just needs more experimentation and practice.

      Thanks again for your input!

      Dave Z

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  5. Additional tracking and stability from lateral resistance devices near the ends..... hmmmmm..... maybe a nod to experimenting with twin centerboards on a barge sailer? One shallow draft ketch (with somewhat long but very shallow keel), with twin centerboards, apparently could self steer on all sail points after balancing up the ketch rig. Maybe increased steadiness on a flat bottomed barger? Who knows? Maybe unnecessary to begin with.....

    ReplyDelete
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