Friday, January 29, 2016

Getting Shippy Part Two

In my last post I was musing on the idea that being dis-masted in a box barge might be preferable to capsizing.  In that regard having some redundancy with multiple masts could be an advantage.

Multiple masts allow me to have a lower rig, with lower center of effort, and smaller lighter poles that are easier to take down.  Plus, I think I would have more control of the boat.


In this latest iteration we have three sails identical in shape and proportion but varying in size with the largest aft and the smallest forward.  They are straight out of Hasler/McLeod.  The sizes are 218 s.f. with a pole rising 20 feet from the tabernacle, 124 s.f with a 14 foot mast above the tabernacle, and 92 s.f. with 12.5 feet above the tabernacle for a total sail area 434 s.f.  A little on the under-powered side I'll admit.

But here are the advantages:

All three masts can be straight aluminum schedule 40 pipe.  They are short enough not to be too ugly without a taper.  All three masts are light enough to raise and lower with ease.  The sails are all small enough and light enough that everything can be managed by hand and without a winch.  These things are important to us as we get older.


Supporting structure for the tabernacles is not going to be a problem.  I'll probably get a metal tabernacle welded up for the fore mast since it is out on the bow and traditional 'bury' won't be accommodated.  But spreading the torsional loads will be a cinch with a welded fabrication.  It's not a big sail out there anyway.


Tabernacles are off center

I haven't worked out the center of effort for this rig but I imagine it would put my lee boards a bit further aft, or increase the size of my rudder.

Anyway, I think it looks cool.  Still thinking on it...

Thursday, January 28, 2016

ZIP Level

I'm borrowing one of these to facilitate setting up my bulkheads and framing.  It sure makes this kind of job easy.  It is like having a builder's level but not needing a helper.  It basically works as an altimeter that measures the difference in atmospheric pressure between the control unit and base unit (connected by a hose).  It can be set to super accurate mode and discern the thickness of a sheet of paper.  In the normal mode, which I use you are good to 1/16" inch all day long.  My setup is pretty darned straight I must say!



Opinions Versus Knowledge

Getting to this point in my design and build has taken a lot of time just doing research.  Finding out what other people have done, what works, what doesn't, what is worth trying at least, what should be abandoned as an idea entirely - it all takes so much time to sort through and filter.

Knowledge based on fact and experience is one thing and an opinion is something else entirely.  Both are valuable though.  A statement of fact from a credible source can be almost taken to the bank.  An opinion from whomever warrants further investigation.

In the end, you have to do your due diligence and make your own choices.

Here is something I'm working on now:

My main mast in it's present form (as a fantasy in my head) extends 26 feet above the tabernacle and will carry a sail of about 450 square feet.  Most of what I have read out there on the Internet says that to size your mast you must first know the righting moment of your vessel.  Sail area is disregarded.  In essence what the size of the mast is based on is strength required to withstand a heeling force of around 30 degrees for said vessel - plus a safety factor.  Say 3 for a heavy displacement cruiser or 1.5 for a racer.

A narrower, lighter boat will heel easier than a beamy, heavy boat so the scantlings for the mast will be much smaller.

Attending to the problem in this manner, where sail area is not a consideration -  only righting moment - ensures a mast that won't buckle or break regardless of what is thrown at it by Mother Nature.  Hurricane, gale, Williwaw - doesn't matter.  The boat gets knocked down but the mast don't break.

So, this is a great way to approach the problem for a conventional boat.  Meaning one that will heel.

What if the boat won't heel (easily) and is more like a fixed and rigid object?  Our boat has a crazy big righting moment.  I would not want to even think about the righting moment at 30 degrees for a boat that is 10'8" wide for its full length of 34 feet, and may weigh fully loaded 6 or 7 tons.

Bottom line is I don't really want the boat to go over that far any more than I would want to experience a 30 degree heel on the Spirit of Vancouver Island.


So what I'm mulling over at this point is would it be better to break or bend a mast in our sailing barge than to capsize it?

Opinions welcome :-)

Anyway, she's still going together...having so much fun!


Tuesday, January 26, 2016

Erecting The Bulkheads

Finally I've been able to get the bulkheads and some material down to the hoarding.  We've been having so much rain here I have had to wait for gaps in the weather lest I soak the material on the trailer.  So far I spent the morning setting up, spacing and leveling.  Soon I'll be able to frame in the curved fore and aft bottom stringers and tie them into the side stringers and transoms.  Shouldn't be long until it looks like an upside down boat!

The first layer of 1/2 inch ply will go onto the sides and bottom with epoxy coated deck screws and PL Premium.

I was planning to use Titebond III along with Raptor polymer nails to laminate on the second layer on the sides, as well as the second and third layer on the bottom.  I'm worried about voids though.  I may spend the extra money and go with epoxy for those layers as originally planned.  If I stick with the Titebond III I want to clamp somehow.  I was thinking about driving a screw and immediately driving a polymer nail beside it, extracting the screw and moving on - say every six inches or so.  The Raptor nails hold really well in tension but won't pull the material together like a screw.  Once the screw has done its job though the nail is strong enough to take over holding it.  I probably would not have to clamp in that manner with the epoxy - just slather it on, lay the ply and nail it with the polymer nails.

The jury is still out...

Sunday, January 24, 2016

AUTARKIA

The ancient Greek word 'AUTARKIA' - or its modern English equivalent 'autarky' means self-sufficiency and independence from external events.  It is certainly a theme that strikes a chord with us in spirit if not in practice.  Indeed it is an ideology that cannot realistically be achieved in practice - we will always be dependent upon someone and have others dependent upon us living as members of some sort of community.

But how can we be of help or service to others if we are nose to the grindstone - caught up in the daily trappings of a continuously degraded conventional life that depletes all of our time and all of our physical, mental, emotional and financial resources just to look after ourselves while we watch others suffer the same fate?

As we get further and further into this state of contraction that we seem to be entering , that may be long lasting or permanent, different ways of living will be requirements - not choices.  But different  arrangements don't have to include  living in a tent community in a park because one waited too long.  Being proactive after having recognized that things are not likely to get a whole lot better can allow for some time to consider alternatives and implement them.

And they don't have to be bad at all.

Tiny homes, simplifying, downsizing, vegetarianism, focusing on health and relationships, growing food, paying off debt, living in communities of extended families are all options among hundreds of others.  The problem is getting past the denial of the very likely probability that things are going to change.

Our goal is to try living differently and honestly show  a process of change - with the downsides as well as the upsides - that we feel will have an ultimate positive result as an example to those we love.  We are not however, providing a template for others.   We don't suggest that anyone should follow exactly what WE are doing  (a comfortable boat - some sort of modest and cheap land base - modest income - time for art, health, love and family).  We just want to show the possibility that there can be pleasant alternatives .  We have talked the talk long enough.



AUTARKIA as an acronym also serves to reflect other values that are important to us - Art, Utility, Truth, Amity, Reason, Knowledge, Independence and Ability.

Yes.  We will name her AUTARKIA.

Wednesday, January 20, 2016

Moving Along And Thinking About A Name




We started tarping up the hoarding today...I'll finish off the ends tomorrow and put in a bench.  And THEN we can erect our bulkheads and frame up the hull.  Looking forward to some rapid progress on from that point.


In the meantime, Lorri and I are working on a suitable name for her.  And it has been a while since either of us has been an expecting parent!   This has been hard..

We're getting closer though.  What we have decided upon is an acronym - probably six letters - that is a real name or sounds like one and rolls off the tongue nicely.  It will reflect the spirit and concept of the project and will be very meaningful to us.  We have a few in mind but will make a firm decision soon.  Stay tuned!

Tuesday, January 19, 2016

What Goes Around...

I'm back to what I originally wanted - bridge capability.  The advice and suggestions in coming up with this latest design have been great and I can't say thanks enough to those who comment on this blog and help otherwise.

I have here a ketch - both sails are junks.  Both are in tabernacles - the aft one offset per advice.  I will beef up structure forward of the bulkhead to handle the loads.  The main mast extends 26 feet above the tabernacle and the main sail is 450 s.f.  The mizzen mast extends 18 feet above the tabernacle and the sail is 130 s.f. for a total sail area of 580 s.f.

I can play around with the sail shapes and sizes later and will appreciate any help dealing with the nitty, gritty details.  However, if I can commit to the two tabernacles and associated structure I can go ahead with my build for quite some time.




A tabernacle either end of the cabin with the aft one offset is exactly what Dave did with Slacktide.


 Sometimes I don't know why I just don't listen... 

Monday, January 18, 2016

Getting Shippy

The tall masted high aspect ratio rig in the previous post probably would have the best sailing characteristics of all I have drawn so far...and I only base that on empirical evidence gleaned from research and from comments and advice from those who are helping me.  The more that I think about the downsides though, the more it bothers me.

I do want to get under the bridges.  And I don't want to spend about $6000 for a pair of aluminum flagpoles.

So I've been back to the drawing board and have come up with a a 3 masted rig as suggested by Robert.  The fore and aft rigs are sprit sails of just under 100 s.f. each and the masts and spars can be made up with common lumber.  The masts themselves are low enough to get under the bridges without lowering them.

The main is a junk sail around 300 s.f. and is low aspect ratio.  The mast would only need to extend slightly more than 22 feet above the cabin roof.  If I made it with an aluminum extrusion (straight tubing)  I may be able to hinge it and sleeve it to lock - as described in some JRA posts and the Tammy Norie blog.

I'm still in the thought process with the whole thing but I'm hoping I'm on the right track for the boat I really want.  Giving up the bridge capability would be a big compromise.


Decisions, Decisions. My Head Spins...

I have had lots of feedback from those in the know regarding a suitable rig.  Most everyone who has generously considered this project agrees that our boat should have two equal sails for ease of handling and for the size of the boat.  I want to defer to their expertise - for I have none as far as junk rig is concerned - but it does raise an issue or two.

For starters, the only way to accomplish a suitable two mast arrangement for this boat is to abandon the idea of tilting masts.  It could probably be done if I threw enough time and money at the situation but I don't want to deplete my resources.  So stepping fixed masts is the way to go.  The upside is that there is lots of info and literature out there to guide the way so I don't really have to invent anything.  Apart from sewing up another sail, I will have saved an enormous amount of work.


A high aspect ratio two masted rig will provide over 500 s.f. total of sail area.

But the bridges...

In previous posts I wrote about the area here where I live.  I want to ply the Fraser River, Harrison River and Harrison Lake as well as forays out to the Georgia Strait.  In the case of the Fraser the railway bridges are not an issue since they can be swung without having unreasonable wait times.  The railroad is talking about eliminating manned operation and doing it by remote control from Calgary but it will take just one unstoppable gravel barge doing some serious damage during freshette - or upon serious consideration of the potential of that happening for them to abandon the idea.  In any case there is quite enough commercial traffic on the Fraser to make timely bridge swings remain for now.

Getting up the Harrison River to Harrison Lake is another issue.  There is a railway bridge but they must send an operator to open it.  It takes a day or two notice and that's o.k for me.  But there is also a highway bridge and getting it swung can take weeks.  So I have to weigh the trouble and expense of tilting masts against the projected frequency of our trips up the Harrison.  My suspicion is that we will use the boat in Harrison for a while but will want to get out to the Strait once we are used to it.

Another issue I must consider is the aft mast position.  As I have drawn the boat (and have begun to build it) I can't see any other option but to place it in the galley at the foot of the companionway stairs.  I have lots and lots of room to accommodate it below as you can see in the drawing.


It does, however prevent a conventional sliding hatch.  I've come up with a solution though and it could be a hatch that slides off to one side.  I will need to think about coamings, a curved track and so forth, but I think it is quite doable.


All food for thought...

Saturday, January 16, 2016

A Yawl Rig Proposal


I've worked up yawl rig here that provides a total sail area of 553 s.f, with a 506 s.f. main and a mizzen of 47 s.f.  I have yet to design a rudder and lee boards but can adapt their design and placement to match this rig.

My plan is to build a mast from 6061-T6 aluminum extrusions.  It can be in two pieces telescoped together, with a lower section of 7 inch diameter by .125 wall thickness 15 feet long, and an upper section of 6 inch diameter by .125 wall thickness 16 feet long.  The mast would weigh about 92 lbs.  The large diameters provide a lot of strength but allow lighter construction - important for ease of lowering for the bridges.  I will need to make a spacer to adapt them together since the inner diameter of the 7 inch and outer diameter of the six inch are off.

The mast extends approximately 25'4" above the tabernacle.

The yard and boom are 3 inch extrusion, with battens of 1-1/2 inch extrusion.  Boom and battens are 22 feet long and the yard is 18-1/2 feet long.

The mizzen is mounted on a tabernacle over the engine well, and pivots forward.  I've eliminated the need for a boomkin by carrying the boom forward with a tiller arrangement. I can haul the boom into desired position with the tiller and drop pin it to secure.  The tiller can fold out of the way.  I'll just have to move it when I tack.  The main sail sheet can be secured on the mizzen mast.  At the dock it can all be swung 90 degrees out of the way.


I am going to need some help to determine if the mast is strong enough with the 1/8 inch thick material.  If I have to (the boat has a HUGE righting moment) I can always go to the .250 thickness on the lower section.  I shouldn't need to beef up the upper one.





Tuesday, January 12, 2016

TLAR

TLAR: Short for 'That looks about right".  It is a school of thought in the informed layman's culture of design and structural engineering - an education based on a lifetime of building and breaking things and learning from the results.

It more often tends to result in structures that are overbuilt rather than under built - easier to get away with in a sundeck or cabin, and even in a boat if it isn't meant to go really fast.  I have also seen it work with home-built aircraft design.  No engineering, just common sense with a firm respect for what has worked in the past.

However,there is a risk to making something too strong.  When a stress riser is reinforced  in one place, it just moves on.  Sometimes it is good to know where something may break instead of having a very nasty and consequential surprise elsewhere.  Flexibility and flexing keep things from breaking.  But too much flexing and you get fatigue.  Too much stiffness in a light structure and the result is highly stressed joints.  No margins for error in the design and construction of these joints.

The shape of a structure has a great bearing on its strength.  Curves are strong.  Compound curves are stronger - consider the egg.  The gain is strength combined with lightness.  The downside is complexity of construction.  A square box like I am building does not have any of those curves - save for the bottom curve-ups at either end, and the camber in the roof.  I compensate with heavier scantlings.

The greatest contributor to strength in my boat however, and in any square boat, is the fact that it is an enclosed tube.  This has been well described by Dave Zeiger in his blogs.  I can give you an idea of how well a box can be reinforced by enclosing it is by holding a simple square Tupperware container that is made of very flexible plastic.  With the cover off, you can grasp it in your hands and twist it many degrees measured from one end to the other.  Snap on the cover however, and the whole thing stiffens right up and you can't twist it at all.

Any opening in said box weakens the structure.  A load path must be created around the opening.  I'll give you an example of such load paths when used in aircraft.  A Boeing 737 (of which I have some intimate structural knowledge) is skinned with aluminum sheet that is typically .071" in thickness.  That is just over 70 one thousandths of an inch.  This skin carries most of the structural load of the fuselage.  There are frames and stringers to keep the shape of the fuselage but the skin is the primary load carrier.  Because people would be freaked out in an aircraft that they could not see out of, there must be windows.  These holes in the skin structure must be dealt with so that it is not weakened.  That is done with window frames made of cast and forged aluminum, each riveted to heavy stringers.  The loads that would normally be carried through ounces of .071" skin must now be directed around an opening with structure that weighs a few pounds.  Airplane designers would LOVE to eliminate windows altogether and save all that weight.  We may see that in the aircraft of the future (barring societal collapse) and people will look at the outside electronically.

Sometimes a window can be part of the structure as well.  Windshields and rear windows of most modern automobiles are structural and contribute to the stiffness and strength - especially in uni-body construction - pretty much as all cars are now.

The weakest openings in our boat are going to be the cabin hatches at either end.  Extra consideration for the forward one is in order, since that bulkhead and roof structure will be integral to the main mast support.  I will be beefing this area up accordingly, and no, there will not be any finite element analysis used in the design.  I just don't have the math.  We will be using good old TLAR.

Here is a stack of bulkheads:  Soon be time to set them up.







Saturday, January 9, 2016

Titebond III Test

Since there was a comment on my last post that Titebond 3 might be a better option for laminating fir plywood, and since I have some in the shop, I think another test is in order.  Titebond 3 is a great glue and I have used it in the past, but only in applications where I have been able to tightly clamp it, or screw it down.

I will be laminating my ply layers however without high clamping pressures.  The first layer will be glued and screwed to the framework so clamping pressure is no problem there, but subsequent layers will be nailed down with Raptor polymer nails.  I can weight down the plywood before nailing, but will not achieve anywhere near something you could call clamping pressure.

Nonetheless, I have a feeling that Titebond 3 will be stronger in tension than across the grain in fir plywood.  It is worth checking out.  Here goes:


I rounded the small ends with a belt sander so I can get a wedge in to break them apart.  Glue got smeared on one piece only since that's the way I'd be doing it with the boat - paint on some glue and then lay a panel down and nail it.


I just stuck them together by hand and am letting good old atmospheric pressure hold them together.



We'll let the clock tick and bust it apart tomorrow....


Early next morning the instruments of submission are employed...



And the wood fails, not the glue!



So for my application, and the reason for the tests in this and the previous posts, was to see if either PL Premium or Titebond III would be suitable to laminate the layers of plywood that will make up the bottom, sides and decks of my boat.  In addition to the glue these layers will be fastened with Raptor polymer nails to the tune of 4 per square foot.

Based on this test, and the ease of application of the Titebond III compared to PL Premeium, I am leaning heavily toward laminating the ply layers with the Titebond.

Friday, January 8, 2016

Lepage PL Premium Construction Adhesive Test

I'm using this construction adhesive to put the boat together (along with coated deck screws).  I'll be using epoxy, however, for plywood lamination and fabric covering.  The joints put together with the PL Premium should never get wet at all although the glue is touted as being waterproof.   I've used it before in house construction and the stuff is tough and strong.  The 825ml big tube goes for $13.50 CDN around here when bought by the tube.  Perhaps a bit cheaper by the case.  One of these tubes goes a long way.







As far as boat building goes though it seems to have an enthusiastic following but is despised in other (I suppose purist) circles. Check out the forums if you are interested in the discourse.  I'm not.

But for the sake of a little fun at the end of the day I thought I would conduct a little test.  It was suggested by someone on a forum that PL Premium has no gap filling qualities and is quite weak when used to bridge a bad joint unlike epoxy.

But I think it would be just as strong in tension as fir plywood is across the grain, and therefore would have excellent gap filling qualities in that regard.  I bet it would laminate plywood just fine.  So here is my little test:



Two scrap pieces of 1/2 inch marine fir plywood.



Some spacers made of floor mat slightly less than 1/8 inch thick.



Spacers at either end.



A bead of PL Premium.


PL Premium squooshed to the thickness of the spacers.  We'll see what happens after it cures.  I bet that when I pry them apart the plywood fibers will tear and the glue will remain intact.  We'll see tomorrow...



In the meantime look at this bulkhead ready to be set up (inverted) to build the hull.  This one is going at the aft end of the cabin where the companionway is.  You can refer to my drawings in the first post to see it in context.  But just walking around it it and imagining the rest of the boat in reference to this has me - and more importantly Lorri - excited about the space we'll have.  That's 10' 6"" interior width for the whole length of the boat!





Okay.  I couldn't leave it alone for the full 24 hour cure.  I glued them up yesterday around 4:30 p.m and it is 10:30 the next morning.  I brought out the instruments of destruction and knocked them apart.



It's plain to see that the Douglas Fir plywood fibers failed and that the PL Premium remained intact.  Armchair experts....sheeesh....

This has got me to thinking about doing all my laminating with PL Premium and saving the epoxy strictly for glassing.

Wednesday, January 6, 2016

Keeping It Simple

We have a little boat we keep down in the harbour here in Mission.  We take her out on the Fraser for day trips, but in reality we could take her just about anywhere in coastal BC.  Rosebud is a Volvo powered diesel mini tug/trawler that I bought in an unfinished state without interior or systems, though she was usable.  I spent about a year of spare time finishing her out and equipping her.


She is a novelty boat.  Overall length is 15 1/2 feet but she has all the gewgaws.  I put in a head, woodstove, galley, shore power, GPS/depthsounder, anchor windlass, vhf, remote control spotlight, LED lighting in and out, custom electrical panel and engine control, wiper, fan and probably other stuff I can't recall at this point.  She could sleep the two of us if we were inclined but we haven't done any trips with her yet other than the day outings previously mentioned.  We'll be selling her one day.

She has been an exercise in the complexity I simply don't want in another boat.  Everything is new in Rosebud so it will be a while before things begin to break down.  It's just a matter of time.  And doing all of this wasn't cheap to begin with.

Other boats that are kept here in Mission have at least that level of complexity and for most of them quite a bit more.  A neighbour of ours down the dock has a trawler with two heads, two steering stations, two sets of electronics, two engines, central heat and so on.  He runs his engines regularly at the dock and found one seized up recently.  Water got into the crank case through the exhaust due to waves and a faulty flapper valve.  Fortunately, there wasn't any damage and upon cleaning her up, fixing the flapper, and replacing the oil the engine was fine.  But I don't ever want to experience the stress I witnessed the day it happened.

No sir, our boat is going to be simple.

For starters no inboard.  We are going to put a high thrust outboard on our boat.  Yes, it will be gasoline powered, and yes it will be way more expensive to run.  All the more reason to sail whenever possible, and when we are in calm water like Harrison lake we'll use the Yuloh.  The advantage with an outboard is when it breaks, out she comes and we fix it it in a warm shop.  If it's too far gone then we can replace it with another abundantly available outboard motor - any brand - because there are no compatibility issues.

No complex plumbing.  We will use a simple 'composting' head that is basically a nicely dressed up Home Depot bucket lined with a bio degradable bag and cedar chips.  No smell, a pleasure to use.  Simple.  But we don't pee in it if possible.  That gets collected separately.

Potable water will be in large jugs.  I'll have a spot to put the current one in under the sink with a tube/ footpump arrangement to a spigot.  I will also install a larger water tank - probably RV surplus - for water for showers.  Technically that will be potable as well, but we don't have to be worrying about it since we will not generally be drinking it.

Hot water for showers:  Aforementioned water tank will be accessed with another foot pump to a spigot.
Said spigot will be able to fill a dedicated water vessel made from S.S. - say a gallon or so - that sits permanently on a single propane burner on a galley counter (I have the space!).  This vessel will have another spigot at its base so that no one will ever have to handle a vessel of this size.  We don't want to get scalded.
So showering will involve foot pumping desired amount of water into the heating vessel, heating it up with the propane burner, draining said vessel into a pump up garden sprayer (modified with a hand held shower nozzle).  The 'shower' it self is a water proof sit down tub in under the 'chart table' forward of the head.  Just lift up the cover and there is your shower or a place to hang wet gear otherwise.  It gets drained overboard with another foot pump.

So we WILL have propane.  I thought a lot about this and it makes the most sense for heating water and cooking.  And since we both really like to cook, the next most complex thing on board besides the engine will be a Dickenson range with an oven.

We will heat the boat with a wood stove.  Simple.

Electrical:  We only need it for lights and electronics.  So a couple of deep cycle batteries will do.  There are a bunch of simple ways to keep them charged which I will explore in the future, but my plan is to keep electrical demand as low as possible.  So LED lighting inside, and LED nav/anchor/steaming lights.  We will want a receptacle to charge phones and computers and a handheld VHF.  That is as far as I'm going with electronics - we simply don't need any more than that.  GPS and depthsounder are not required.

In the meantime, I'm still building away.  Here are the four main bulkheads going together.  I'm hoping to finish them up by next week.  I'm really liking those plastic nails.  They are incredibly strong in tension - way more than a metal nail would be.  They actually bond to the wood from the friction of being driven.






Friday, January 1, 2016

Tilting Masts Continued...

If I go with a single mast then accommodating it will be fairly straight forward.  I can get an aluminum flag pole from Ewing that is 40 feet long, 7 inch diameter at the base and 3-1/2 diameter at the top with a .188 inch wall thickness.  Others have used this pole I think in a free standing  junk mast application but in any case I'll need some help with the calculations to see if it is suitable.

My thoughts are to use a tabernacle with the base set down into a well.  The well would be drained and hatched over, and could hold an anchor and rode, though these would have to be unstowed to lower the mast.  The pivot could be about 6-1/2 feet up the mast and this section could be ballasted with tire weights set in epoxy.  That could make the whole thing quite easy to raise and lower, though the whole works may be fairly heavy.

Here's a sketch:



Meanwhile, I'm building while I think.  Here's a stack of curved stringers for the bow awaiting fairing and sanding.