Pirate Ship computer lofted ready for build

Here's a fabulous page.
http://www.betty-ck145.de/docueng/classic_boats/cruise_boats.html

 

Yes, experienced in boat building in Sri Lanka. First designed and had built a Replica English sailing smack in 1982. In Negombo. In those days loads of small yards building small wooden fishing boats. Manual Fernando's yard took on the job for 40,000rps or about £1000 in those days. Did the lofting for them and was onsite over the 8 weeks it took to build it. They were not confident about tackling anything different but did a pretty good job. Got it shipped back to the UK.

Had a very small yard in those days and made the spars myself and rigged her using traditional manilla, GI wire and engine installation. She's still going strong. Originally called 'Babeth' and now renamed 'Katie'. Still going strong as found a recent advert with her up for sale!

Went over again a couple of years later and designed and built a 44 ft schooner at Welamunkara. Bigger job again but did the whole thing there including making the sails etc

 

Bataan --good reference page--- Nick- I am not familiar with the boatbuilding history of the locals but from the photos looks as if they can turn out a hull. How was their ability in terms of good joinery any close up shots. Have you thought of epoxy and heavy strip plank edge nailed--forgiving in terms of joinery on the hull sheeting but challenging in repairs. The other challenge of course is the moisture content of the timber has to be well within tolerance. --Geo.

 

The only job you seem to be designing for is "looks cool and old and Pirate-y", with no messy reality in the way. In other words a vague nautical fantasy of what a generic late 18th century schooner should be like.

Yes that's true, but way over the top in my opinion. Whats been changed then:-

The rig has not. As pictures of small 18th century schooners apear on here the more it will seem right. Based on the research of Howard Chapplle. And who else's work would anyone go too first? Is the schooner rig the best around? Loads better rigs even in those days- the cutter for windward and square for downwind. But is the rig authentic as drawn? I'd say yes.

Pirates used every type of vessel that is true, like any 'trade' and would assume small was far more common than large. Just from the point of view of it being easy to get six like minded crew together rather than one hundred and fifty. But better to ask some who who know's pirates! The 'Pirate' reference not important, small schooner 1760- 1820 would be a better!

Reckon fairly similar to the 'Marblehead' in profile, only one or two lines plans of the 'Marblehead exist? The midsection is slightly different freeboard is greater and the drag of the keel much less but it was common in fast european schooners used for privateering/mail etc. Could a vessel of this rig and hull fit in this date? Why not?

Structure- planking thickness authentic? Yes, lots of examples of 50 footers then and now built with 1 1/2in hardwood planking. Oak often used in the UK, France and Scandinavia on the hull. It also meets todays scantling rules. Same for the deck though narrowleaf mahogany is a better material than would probably of been used. Is narrowleaf mahogany an excellent boat building material? Well my experience has been good 30 years on the decks of a replica East coast fishing smack built in Sri Lanka and just about every authority on boat building says it's good. Maybe it's only good in european climates or was one of the generic 'mahoganies' that let Bataan down?

Framing- frame spacing closer or the same as lots of traditional designs of this length and date. 30 frames over the length. Frames of less thickness than traditional yes! not historically accurate but meets scantlings rules. Same reason for not including a Keelson. Why would any doubt be needed on longtitudial keel of such scantlings on a fifty footer with internal ballast? Rules say most boats at this displacement or length do not require a keelson especially if diagonal hull strapping is used. The keel scantlings are over the rules requirements anyway . The mechanical ratings are above Oak.

Ballast cast steel ingots (full frame bay length), lipped onto thru bolted cleats thru floors. Clear of hull planking and above floor height run thru. Pitch and cleated full width at every frame.

Does not have beach shingle ballast but cast iron ingots closely spaced. Common to have iron or high density stone or anything heavy fitted in fishing boats or privateers for that matter as unlike freighters the light and loaded condition didn't alter that much. This design does have a lot of ballast and it's higher density than of old, so agree not historically accurate but a better job.

Rebate for keel- please look at the amidships frame not flat or slightly rising but planking strongly angled to the keel. Good landing with plenty of holding for the usual type of rebate. Long and short arm floors common everywhere in the world with this type of rebate. This again is bulk-standard traditional construction.

Deck is diagonal strapped as well. The system works by preventing racking of planks (what hanging and lodging knees also try to do). Restrains planking moving against one another. Works by resisting tension like rigging does on a mast. Wire rope is crap in compression but it holds masts up! Strapping is 'modern' coming in in the 19th century. Not authentic but a very good way of 'diagonally bracing' planking.

Sail area/displacement ratio at the bottom end showing under canvased for modern yachts. Schooners have a lowcentre of effort but all the disadvantages as out lined by Butaan. They sail well reaching however! Reefing traditionally was as I understand it by dropping sail. Fresh breeze the foresail lowered, balancing under main and jib sails, in higher winds the foresail raised and main and jibs lowered. The foresail could be further reefed easily in higher winds being inboard.

Not arguing about that at all about the sailing performance of a schooner, True comments about the upkeep of a wooden boat, they really need looking after, nor the disadvantages of a schooner rig. It will need a crew of four who know what there doing and an engine! Agree some construction is not authentic 1700s. Agree there are other ways of building a good wooden boat. Having designed, built and sailed schooners before I share lots of these points of view.

But I do disagree with some and look forward to hearing something concrete. Scantlings comments are just wrong. If it meets classifications rules then that's fine. The reason for classification societies is to remove 'opinion'.

Are larger scantlings a good thing on traditional carvel construction? Not according to D Gerr (The Elements of Boat Strength).

Over rigged? Not according to calculation.

Rigged wrongly for it's period- just look at the photos or any book on the subject and make up your own mind.

Computer lofting a bad thing? No it's excellent. Fairs lines then are able to take of structural members accurately. Print them on dimensionally stable mylar sheet along with bevels, joints, fastening positions, place those on the timber piece and mark the timber directly. Really good. De-skills the whole job.

 

If interested in this type of boat:-

The Colonial Schooner 1763-1775 (topsail schooners) by H Hahn.
The National Watercraft Collection by Howard Chapelle
The Search for Speed Undersail by Howard Chapelle
Architectura Navalis Mercatoria by Chapman
The Baltimore Clipper by Howard Chapelle

 

Interesting. Thanks for posting that, Tad. One of the reasons I decided to build a steel Colvin design myself was the ability of steel boats to survive abuse in general, and the lines, level of detail and line drawings in Tom's steel boat building books in particular. Lots of nice rigging details & drawings there.

The complete building plans & details for a Pinky schooner are in the book along with permission to build one for own use. Too big & complex for me though so I picked something smaller & simpler.

WRT eucalypts, living in the home of them I'd have no hesitation on using some of them for any structural purpose. Iron bark, blue gum & stringy bark are extremely tough, strong and rot resistant for example and don't move around much once seasoned.

PDW

 

Nick because of my historical connection I wish I were younger--I'd offer my sweat just to be a part of it. Looking forward to photos of the build --Good luck---Geo.

 

Thanks Geo! If it does I'll get intouch! Really nice experience seeing a boat built.Have had labour only quotes from 4 boatyards and pretty reasonable. Someone having a large traditional lugger being built in England at the moment worth looking at just to see how much works involved! :- http://www.youtube.com/watch?v=obgkyS9ZvLc&feature=youtu.be

 

wierd

in a recent issue of Backwoodsman magazine there is an article about pirate ships. The featured ship is a Bermudian schooner named "Lady Hannah" The British navy purchased her, altered her for naval use and took lines off her and built several more. They were reputed to be very fast and sea-worthy and a favorite of local pirates. The lines may ba available somewhere

 

"De-skills the whole job." Is this a good thing?
Obviously the poster has successfully followed through on building boats before and knows it all and can quote chapter and verse and scantling/displacement dogma, so what can I say?
I do note constant reference to books, rules and pictures and not personal experience with 18th century craft and their use.
The too-close framing, caulked ceiling, heavy kneeing and blocking and keelson are for when you get hard aground on a bar in a swell and are pounding her guts out and hope the ship lasts until she floats off on the tide, but that will never happen, since the scantlings are 'within the rules', which are calculated for sailing strains and getting hard aground is not part of the plan.
Likewise the wimpy single X of deck strapping, relying solely on the fasteners at each beam to take the wracking strains of the deck. It's in the rules, so must be right, and is, so long as the thin metal itself and fasteners remain in new condition forever, the wood around the fasteners doesn't deteriorate etc.
As far as Mahogany for decks, we do not have the timber resources available to the poster (mahog is $11 a BF down the street at Edensaw) so don't use it much in our climate.
If casting custom internal ballast blocks to fit the frames, why steel, flaking its rust into the bilge forever? Is denser, heavier lead not obtainable or too hard to cast? I'm confused here. Steel must have some innate superiority I am missing.
As noted before, when being trained as a Museum researcher at Mystic, I was particularly advised to double or triple check anything Howard Chapelle reconstructed, as his work was considered 'popular' and not rigidly researched enough.
He was an academician and not a schooner skipper, so anything he relays about handling is from either word of mouth or reading logbooks (the best source) or ancient newspapers, which no more covered the details of handling a schooner than a modern paper does about driving a semi-truck.
The square rig is not just for downwind, but for maneuverability, being able to adjust COE a great deal, being able to stop quickly, even sail backwards to get out of a jam. A schooner with a square fore-topsail is a whole other thing than a knockabout, and was the usual rig of the times.
The knockabout generic schooner rig as drawn will work, though the topmast is either out of scale or just drawn too fat and long, but a fore-topsail schooner would be more authentic for the times, as the knockabout was for firewood carriers, fishermen like dogbodies and pinkies and general coasters, not something with a pair of fleet heels.
As drawn, the rig will be out of balance when the fore is down.
That description of sailing under that 1000 sq ft main and the headsails sounds like the tiller is hard up in the gusts, or the sheet is loosened and the main thunders like Thor as the gaff whips. Been there, done that with a 60' main boom too many times myself.
In the pictured below engineless 50' schooner (only 30' boom) caught in a very bad gale many years ago we had the foresail split right across in a gust and the ship became utterly unmanageable even with the reefed main due to weather helm, we had to drop the main and run downwind until we were about to hit Duxbury Reef off Bolinas, anchored through the gale in a breaking surf and pumped all night by hand...
This was a converted 1901 W.F. Stone-built SF bay oyster sloop, all work done by hand by me and one other guy, broadaxed the masts from trees, reframed, replanked, hand sewed the Egyptian cotton sails etc.
The first thing you learn when actually sailing one of these things is if the wind pipes up, reef the bloody main and make it smaller, because you might not be able to do so in 15 minutes, but that's not in the book.
Since we're learning from books, I suggest the following:
Sailing for a Living, Basil Greenhill, (a 5 shilling, 1950s museum pamphlet of 75 pages of wisdom).
The Schooner, David R. MacGregor (Naval Institute Press) MacGregor sets the bar high on research with his many books.
Schooners, Basil Greenhill (Naval Institute Press) Greenhill was head of NMM in UK for many years.
Danske Smaskibe, Andreas Laursen (in Danish) Danish coasting schooners, old and 'new'.
Out of Appledore, W.J. Slade. A life in UK coasters from birth.
The Last of the Sailing Coasters, Edmund Eglington (H.M. Stationery Office) A coasting skipper in the 1920s.
The Merchant Schooners, Basil Greenhill (Naval Institute Press) Exhaustive book on UK and other schooners of all types and times.
In the last book, starting on page 286, is an "Autobiographical Note" by Capt. R. Robinson (b. 1873), describing his life at sea in schooners, finishing as a pilot. In the next ten pages he describes in exquisite detail the manning, feeding, pay scales, trades and handling in all weathers of these small ships. If you are truly interested in learning from 'them that has done it', this is a good place to start.
If you already know it all, you won't need these.
The smack and schooner built earlier by the poster have lovely lines and look like good boats, though oyster smacks (which is what she seems to be) tend to be wet and specialized vessels, fast in some conditions.
So far, in my opinion, the poster has proven he knows enough about 18th century schooners to draw pictures on the computer.

I respect faith, but doubt is what gets you an education.

Wilson Mizner (1876 - 1933)

 

I wonder if this project has got started yet

 

Reading between the lines I think his (forta ?) is more building than design, however his presentations show he is certainly has design capabilities. I read some time ago a posting by a well known designer. He stated that he obtains his best and fastest feedback info on an engineering question by making a quazi untrue observation in question form on the topic of his OP thread. His theory was, it gives opportunity for posters to make use of all that book and experimental background. To use their brainpower so to say. I.E. one receives more feedback info from posters trying to correct and set you on the right track than simply confirming you are right. In this case the OP has received excellent input on what could be the weak links in his design. The one challenge in this approach is one has to fight one's ego by acting a little dum. Not a problem for me as I do profess to certainly being more of a builder than a designer, so all my dum questions are for real

 

The poster showed he understood how a computer works, not a boat, and certainly not an 18th century boat.

 

Well he's one step above me on the computer aspect and he's gotten alot of good info off the thread so all in all he has the ammunition to select good design for the build. If the horse is thursty and needs water ?????

 

One can get all the good info in the world, but if you don't change or modify or improve your ideas from that, it's not much good. Every time one of us made an observation about a 'lacking' in his design, he just got defensive and Lawyer-ed up with scantlings and rules, and did not engage in the discussion.
Long ago in the the CG one black night in a raging surf as we were looking for missing boaters and a wave had just broken right on top of us soaking us to the skin and rolling us 90 degrees, our 44' surf boat's Cox'n said to me as the boat recovered and came upright, "you can't bulls**t the ocean", and to my experience this guy smells of bulls**t.