these turbine alternaters are easy to make

[masalai]

If the wood is compatible - (some is not) - I would be so bold as to suggest epoxy 2 part stuff as the glue - Manie & Fanie might be better at this, and sheet with a glass-cloth and epoxy to protect the wood and act as a base to glue the copper-powder/epoxy mix for below the waterline - seems to do a good job in boats I have seen done this way - balsa is wood albeit very light and in need of waterproofing (It is porous and will absorb water if not properly sealed)... so is glassed inside and out as well as sealed by 2 part paints / flowcoat etc over the glass...

[Boston]

ya that two part epoxy is looking suspiciously like its going to be the choice

Im not likely to use any fiberglass although Im sure it has its uses
all woods in this build are going to be traditionally water resistant and able to handle water contact for prolonged periods of time. Ill paint the outside but the inside will be oiled and sealed with varnish just like we always used to do and Ill leave most of it exposed in the finish to kinda show off the workmanship and also cause it allows it to air best
One thing I am working on figuring out is if I diagonal plank the hull what gains am I getting if I do or dont glue the layers together
once upon a time they used to just put waterproofing between the layers and never glued it
the hull planking is red ceder so its going to want to get a little wet in order to form that perfect seal
glass would only inhibit the boats ability to breath as well and add undue stress
it also costs a fortune

Im guilty
I want the boat to be a reflection of what has been passed down and not forgotten, although Im sure no one ever used locking jointery throughout a ship as a typical practice, but for my one off, its perfect, I kinda want it to be something I can leave behind for generations to come when its my time.

[masalai]

What is known here as "western red cedar" is/was used in the strip planking or earlier (and heavier) round bilged cats and covered with glass/epoxy outside & glass/flowcoat inside or something like that - eliminated the need to re-caulk regularly and a thinner layer of timber, than I guess you may be intending... - I am out of my depth somewhat there as I only observed a couple of boats in the build stage... I am sure your skills are up to the task - keep us all posted...

[Boston]

thing about glassing in wood is that the wood is impossible to sound or apply any of the other easy inspection methods to and when it is time to replace something you end up ripping the fiberglass off. caulking is not all that necessary on a ceder hull as it swells so nicely it forms its own seal
and if I diagonal the planks it should be even more likely to swell closed as the multiple layers should act like old ceder shingles do and as each layer gets wet it swells and protects the building bellow after that Its pretty much a mater of good joinery and I got a fast and easy method of joinery on the planking that pretty much forms a perfect joint every time

the original skin on that 57 was 1 1/4 ceder but I want mine a little thicker for that crossing Ild love to do ( Ill have storm shutters installed for any serious open water cruising ) so Im thinking two layers of diagonal 1/2" ceder and one at 1" thing is when you plank with ceder and if you need to steam it to fit you have to dry it out again before you apply it or your not doing your best job. IE dont temp screw it hot or you will end up with a gap when it does finally dry out. Im still just working out how I want to skin this thing. I love the idea of stiffening up the hull with some cold molding techniques but we never used to do that so Im just kinda winging it to see how it might work out. Maybe plywood would be in order at this is really easy although ply is got its own issues of longevity that Im not so sure about.

Ill not only keep you all posted but Ill be asking a bunch of stupid questions as well

B

[Boston]

Erik
I didn't find an engine in the 20 to 100 range but I did find one in the 50 to 125 range so I hope that's close enough

the engine would use 535 lbs/hr at 600psi and run to 1500 rpm with a torque range something like 600 ft/lbs

thing would weigh in at about 250 lbs and you would need a boiler and a few other bits and pieces. From what Ive learned you pretty much always want to run these with a closed loop steam system on distilled water with a little oil added to it

castings would run about $1,700 and you'd need to clean em up with a little machining although the company Im thinking of will actually do it for you if you feel like springing for the extra cash for them to do so

but you will abviously also need a boiler
boilers are monotube these days and so there are fewer welds in the system and so less chance of a steam leak. Funny thing about boilers is you will get the most efficiency by using two smaller ones instead of one larger one
depending on if your actually trying to get anywhere or if your just out cruising.

problem is two smaller boilers that may not run that thing up to its full potential would weigh in at 250 lbs each and they are only about 40 hp a crack so you get more fuel efficiency but less go with two smaller and heavier total boilers

the larger boiler weighs in at 350 lb and would run it like a banshee however you would have less ability to tone down the fuel consumption with the larger boiler rather than several smaller ones the gain being you have a lighter set up

hope that helps
B

if you really want to get tricky you can determin the amount of fuel you will need at any given hp with this groovy calculator I found

http://www.mckenziecorp.com/boiler.htm

100 boiler hp = 6.9 gallons an hour or 3,347,900 btu/hr at 70 psi = 23.6 gallons an hour and Im doing something wrong here

1 boiler hp = 33,475 btu/hr = amount of energy to evaporate 34.5 lbs of water at 212 F in one hour
or 100 hp = 3,450 lbs of steam pr hour
I ton of pellets = 16,800,000 btu pr ton depends on what wood you made the pellets out of
white oak is 22,000,000 per ton
diesel has 147,000 pr/ga =20,000 pr/lb

that would mean your going through one ton of fuel in about five hours
no way is that correct
hmmmm

or the frightening thing
maybe it is correct and I just missed something in the last five pages of calculations or something

ok so here's the Duty charts for the big 4 cylinder steam engine



it will run continuously at 150 hp and 895 lb/ft
cruise at 100 hp and 710 lb/ft on 410 psi and 740 rpm
and I estimate it will use 2000 lbs of steam pr hr at 200 hp
call it 1500 at 100 hp

so hmmmmm what does that work out to in terms of btu pr hour

ok so there are four different ways you can measure horse power
metric = 10 HP
Mechanical = 10,000 MHP
electrical = 10 EHP
boiler = 1 BHP

and these guys are some grumpy old spuds who produce this engine
not real conducive to stupid questions but
its worth a shot
I need to ask em if there engines are rated at boiler BHP or Mechanical MHP cause there is a slight difference in fuel consumption
I knew there was something up with one tone of fuel in five hours

Horsepower (hp or HP or Hp) is the name of several non-SI units of power. It was originally defined to allow the output of steam engines to be measured and compared with the power output of draft horses. The horsepower was widely adopted to measure the output of piston engines, turbines, electric motors and other machinery. Different regions adopted different definitions of the unit. Most countries now use the SI unit watt for measurement of power.
The definition of a horsepower unit is different in different applications; application outside of the context of a particular definition will be inaccurate.
One mechanical horsepower of 550 foot-pounds per second is equivalent to 745.7 watts
A metric horsepower of 75 kgf-m per second is equivalent to 735.499 watts
A boiler horsepower is used for rating steam boilers and is equivalent to 34.5 pounds of water evaporated per hour at 212 degrees Fahrenheit, or 9809.5 watts
One horsepower for rating electric motors is equal to 746 watts
A Pferdestärke is a name for a group of similar power measurements used in Germany around the end of the 19th century, all of about one metric horsepower in size. [1] [2]
An ALAM or SAE horsepower is not a unit of power but instead is a measure of internal combustion engine displacement, and an RAC horsepower or tax horsepower is a differently defined unit of displacement.
Where units of horsepower are used for marketing consumer products, often measurement methods are designed by advertisers to maximize the size of the number produced for any product, even if this may not reflect realistic capacity of the product to do work when used in normal conditions.

which means that these guys are bound to have rated there engines and boilers on the standard HP 745.7 watts and not on the boiler HP 9809.5 watts

now to go ask a more intelligent question
wish me luck these guys have dont bother us with stupid questions stamped all over there web site

what that all means is the calculator that I used to determine btu consumption which was based on boiler HP was probably off by a factor of 9809/745 or about 13 in regards to mechanical HP which how those guys probably rated there engines
so instead of five hours run time on one ton of fuel I should be getting 65 hours run time on one ton of fuel
which is also wrong cause that was also measured at 70 psi and I need I think 410 psi or six times that
so if there is a linear relationship between fuel consumption ( who knows ) and steam pressure then I get 6x less hours than that 65 or about 10.8 hours run time per ton and for 7 tons I get something like what I had calculated before of 808 mile range on 7 tons
in this analysis it worked out to 756 miles per fuel load of 7 tons
close enough and I think I just answered my own question

[rich_solvey9838]

Have you thought of an induction, such as a squirrel cage fan, it would scoop the air and cabe set with a directional vien on top to catch wind flow and air would pass through the side and if you venturied the side ports it would draw more air though increasing the velocity?

Just a thunk, it's a definate head scratcher.

[Boston]

ya if you look through they are shown on some of the turbines

[Boston]

turns out I actually dont need that one huge engine but rather I would get better efficiency with one smaller engine and a back up of the same size
Im going with two 50 to 125 hp each steam engines 1500+ rpm max 600 to 1200 lbs steam pr hour at 600 to 1000 psi each and weigh 240 lbs each

the first set of numbers I calculated for the smaller steam engine spinning at 900 rpm and 70 hp ( a verry efficient rpm for this engine )
which is also a number that does not require a transmission

the second set of numbers in { } is for the smaller engine at max potential

engine torque = 408 ft/lb { 438 }
shaft hp at prop = 68 ( no gear box ) { 121 }
prop rpm = 900 { 1500 }
prop torque = 396 ft/lb { 425 }
displacement = 25 tons
wl =57'
speed in knots = 9
speed length ratio = 1.192
shaft hp available = 68 { 121 }
pounds pr shaft hp available = 736 { 412 }
hp required at prop = 70
lb pr shaft hp required = 716
80% of max prop shaft rpm =720 { 1200 }
theoretical required prop pitch = 15.2 { 9.12 }
1) estimates slip of un-shrouded prop = 40.01%
2) estimated slip of shrouded prop = 17%
1) required un-shrouded prop pitch at 9 knots = 21" at 25" diameter rpm = 720 { 15" at 22" diameter rpm = 1200}
2) required shrouded prop pitch at 9 knots = 18" at 22" diameter rpm = 720 { 12" at 22" diameter rpm = 1200 }

best pitch turns out to be 22 by 18 shrouded for a prop efficiency of 85%
I calculated the boiler efficiency of 80%
and a speed of 9 knots

fuel consumption equals

1 btu = 1055 J
good wood pellets contain 17,000,000 btu per ton at a cost of $175 to $225 each
works out to about half the cost per btu of diesel but its bulkier and weighs more

41 Kilowatt Hours = 147600000 Joules
pellets get 17 000 000 Btu per ton = 17 935 950 300 Joules per ton
so 1 ton of pellets will drive the hull at hull speed for 121.5 hrs
I think thats bound to be wrong
hmmmm
how about 121.5 x .84% efficiency = 102 hours or 938
still seems like to much
boiler efficiencies in the 90% range are not uncommon
my pellet stove claims an ash remaining of 1% which means there was a near impossible conversion to the gaseous state
to be safe Ill say a 80% boiler and burner efficiency rate combined
102 hours x .8 = 81.6 hours or 751 miles per ton of fuel and I can carry 7 tons although typical load would be 3

at the same speed and revs the diesels would be at there lower limits and burning 1.3 gallons an hour each or 2.6 gallons an hour for both
over 81 hours thats 210 gallons at $3 a gallon or $630
the pellets per ton to go the same distance cost about $175 - $225
although the diesels would most likely be pushing a smaller diameter prop of less efficiency and at a higher rate of consumption per hour to speed along
why, is my next question
instead of bombing around the bay like some fool in rut
how about slurping down a martini and wondering if the girls going to remember she is naked before that sail boat slides past and and there kids start screaming for grand dad to come see

[Boston]

Ok been reading up on some of my older threads and I thought I'd do a little thinking out loud and see what I come up with

I'm considering building something smaller to keep me sane while I await that fated day I actually do retire.

its a 29' runabout with approximately the following considerations
oh I'm not really all that interested in bombing around the PNW but I do kinda like the style of this boat just for day tripping.

Length: 29'
Beam: 7'3"
Approx. weight: 5400 lbs ( change to reflect alterations in materials and equipment )
Engine: Crusader 8.1L MPI
Engine HP: 385 ( change to no greater than 175 hp or electric)
Fuel capacity: 51 gallons ( change to 100 g )
Hull: Mahogany ( change to epoxy impregnated poplar ?)

so roughly at hull speed I need 13hp shaft hp

if I use the warp 11 motor I'm using how much juice at say 15 hp



call it 176 amps at 72 volts or 12,672 whats of energy/hr

over an 8 hour discharge period the gorilla batteries have 640 amps available or 80 pr hour each at 8 volts

so it would take 9 batteries to run for 8 hours at 176 amps and 72 volts
and 9 batteries weighing in at 424 lbs each total 3,816 lbs. The weight being the critical issue on this one. OK so I add in a gen set and a couple of retractable wind turbines for recharging but eliminate the diesel engine, I add for the actually elec motor.

I'm going to save weight using poplar instead of mahogany and spend it on fuel for the generator.

hmmmm
if I run right at hull speed

if I drop down to say 6 knots I could run for nearly 12 hours unassisted by the gen set and likely 24 hours assisted depending on the size of the gen set which I was thinking of at say 10 hp

B

ok just looked up that engine and it weights 1200 lbs
mahogany is about 20% heavier than poplar
the drive train is way simpler with electric than with internal combustion so minus the transmission at 500 lbs
I gotta add for the electric engine though and the gen set