[PUP] PPM, Convergence, narrow boats - my perfect passagemaker and costs (long)

[hannu venermo]

Mark, everyone ...
I am one of those who believe that the (was) current trend of floating 
condos is a very bad idea.
The experience of the Dashews would tend to support that re. unsailboat.

Reasoning;
Why "floating condos";
-----------------------
The main market for these boats has been the US (And the UK to an extent).
95-99% of these craft sit at dock.
They are never or almost never deep-water sailed ... avg use of these 
boats is 3-5 days/year.

The main use of these boats is entertainment/leisure.
They have *absolutely nothing* to do with passagemakers.

Thats why these boats need stabilisers - due to overly wide, full bodies.
They are too full, too light (ie have insufficient displacement) and too 
short.

And when the admiral experiences heavy says in one -
she does not want to repeat the experience.

Better designs;
------------------
The *only correct solution* is appropriate design, ie length/ width 
ratios, and much, much narrower bodies.
The Dashews give excellent empirical data with the unsailboat derived 
from multiple accelerometers (measure g-forces), and they have compiled 
data that show unequivocably that the unsailboat is, iirc, about 300% 
more comfortable than their very, very good sailboats (which were best 
in class !). !!

Its a bad idea to have large full bodies.
They can *never* be nearly as comfortable as a properly designed narrow 
hull.
When the water moves ie rolls, the boat will roll with it. Stabilisers 
ameliorate the effect of roll, but in no way make the boat track 
straight, level and upright - it will always move along with the water.

Now, the other trend over the past 20 years has been ridiculous cost 
increases related to length.
There is absolutely no good reason for this - none.
The volume of a boat increases with cube of length -yes. But you do not 
need to and should not cram it full of "stuff" which is where 95% of the 
cost comes from.
A long slim boat ("Idlewild", a George Buehler design in steel, built a 
few years ago, is an excellent example, and proves this.) was about 1/3 
the cost, 200% the comfort and 300% more efficient than equivalent- 
length typical trawlers like the Nordhavns.


Length/width/comfort/efficiency;
--------------------------------
Modern bodies like the Nordhavns have about 4.5:1 length/width ration.
The Dashews "unsailboat" has about 6:1.
Cats have 6:1 - 10:1.

In my (studied, experienced) opinion the only correct choice is around 
the 5:1 - 6:1 ratio for single hulls used as passagemakers.

These are the nautical engineering- based facts;
+ The deeper you sit in the water, the more comfortable you will be.
=> The heavier the boat, relatively, the better, stronger, more 
comfortable it is
+ The bigger your Length/Breadth ratio, the faster, more efficient your 
boat will be

Cost;
----------------
You can have any level of comfort you want, as boats are custom built to 
order.
You can also have any level of fit, finish and appliances you care to 
pay for.
Length does not, in any way, contribute to cost.

The *only* reason length does contribute to new boat cost, today, is the 
brokerage/sales model used. Its just like the real estate market. At 
this time, in the current market, it is to the advantage of everyone in 
the supply chain to jank up the price - the seller, broker, yard, 
equipment suppliers etc. etc. It is to no-ones advantage to build to a 
given level and a reasonable cost, as the *customers in the market due 
not want that*.

A 24 m great trawler yacht can be scratch built, reasonable house 
finish, and all conveniences, for 270.000  new.
After that, everything is luxuries you pick and choose.
Sail-away condition, everything onboard.
The hull is only 90.000 or 1/3rd the cost. This is welded, primed, 
painted, engine bed and steel fuel tanks in place.
This is for 50-60 metric tons of hull, btw. 5 mm plate.

At a 270k cost, the builder would sell it at 540k, the broker adds 
25%, and sale price is 680k.

I propose we tackle the cost issue next -
as it drives everything else: size, L/B ratio, engines, fuel, range, 
comfort, fit/finish etc. etc.

What does everyone want ?
At what cost ?

Please, please everyone -
I am not denigrating anyone who has bought a very expensive Norhavn or 
other yacht full of costly "systems".
It may be what *You want* which makes it a great choice, for you, and 
anyway - what better choices are there ?

So try to add content if you can, and use examples, quotes, references 
where possible.

For myself, I want;
1. Hurricane-survival capability ie coast guard cutter strength.
2. Large tanks, long-range capacity
3. Very reliable, strong
4. Very comfortable long term living
- All normal house appliances
5. Decent living space and size
- Low cost
- Low running cost

In the same order (What I need to realise these goals)

This means, due to above.mentioned desires (this is the definition or 
mission statement);
1. strong, rugged body (in steel - alu is out due to cost)
2.
-rel. small engines (twins as they are small and cheap)
-very large props (efficiency is increased dramatically at cost of 
dynamic range)
-high transmission ratio
-slow speed props
-commercial level hatches and portlights (very easy - make them heavy in 
steel)
3.
- excellent electrical system (220 V throughout, nothing runs on dc)
- very few systems, redundancy
- all system rated to run in workboat use, ie 24x7 continuous use or near it
4.
-QUIET ! Noise is Nr1 weak point in most boats
-ability to run on-hook without generator 1 week minimum
-dual freezers, fridges, etc. std. household commercial energy-efficient 
stuff
-large battery bank (its also internal ballast)
-large invisible solar cell bank (on pilothouse roof ie 10-15 cells)
-large waste tanks (2000-3000 l)
-led lights and extra (halogen) worklights
5.
-Designed for one family ! (You only have 1 family in your house, right ?)
-For me, this is 1 couple, 1 workspace/library/office as guest room, 1 
convertible (your options may differ)
-Large comfortable saloon, pilothouse, galley (like the unsailboat)
-Sauna (I dive and guide)

-Excellent engineering space (together with the engine room, engines 
hermetically sealed, soundproof (put the batteries round them in steel 
airtight containers)
-Full machine-shop onboard (and I mean ability to rebuild anything 
including the engine crankshaft, cnc-stuff)

: To make a perfect passagemaker

Results;
Low running cost implies an efficient body and small engines
An efficient long body gives speed, efficiency, comfort
Small engines and large props mean deep depth
Large slow props and large transmission mean best efficiency is only at 
a narrow speed range
Low cost means everything must be machine-shop built - cannot be bought 
from "yacht store"
Efficiency and reliability means everything must be industrial level 
technology
Industrial stuff is big, heavy, quiet, slow-running and reliable

Drawbacks;
Draught is deeper than most
Fit and finish like a normal house - its not gold plated when built to a 
low-medium cost
Cannot go fast (but its actually faster than anyone else at the price 
point , due to the long hull ! -;) )
Technology is more like a farm than a Rolls Royce (but its much more 
powerful and quiet and reliable and safe and cheap and easy to maintain)
Heavy (I like it - I can use 200 kg anchors and so on (because I will 
use and have big winches), and its very, very safe)

Other things I will add for myself (You might not see the need for)
-Dual redundant cabling installed at build time
--So I can change, add, fix or run any new or old instruments etc. 
without running new cables
---Use a few 50-pair cables for instruments on opposite sides of the boat
-Steel ducts inbuilt for plumbing, hvac, electrical
--So in a 300 degree C fire the cables, plumbing, connectors etc. don4t 
melt, burn or smoke until the fire is under control
--So I can flood everything without killing instruments, engines, system 
etc. under fire
--So it wont flood or leak in a knockdown (ducts carry air or water 
unless watertight - so make the duct system watertight
-Multiple large pumps (for my dive stuff)
-Everything runs off engine power take-offs
There is (exactly) 2 of everything, and everything can run off either 
engine, and can be switched on/off to either engine remotely !
-Compressors (air), hydraulic pumps (steering, winches secondary), 
generators, water pumps (for flooding and salvage stuff)

As a technical note;
Running industrial stuff and pto stuff means *everything* is 5-20 hp in 
power (About 10 more than typical yachts), silent, and about 1/3 yacht 
price !
The dual-pto is trivial in engineering terms (parallel shafts, dual 2" 
bearings, htd toothed belt, 2 idler pulleys ) and very, very cheap and 
reliable
Running 2 in dual-cross-tandem means you keep using and exercising the 
engines so they never fail and corrode due to lack of use
Everything must be modular-fit ie 2 ft centers and std (14 mm machine 
grade, 12.8 high-tensile) bolts
- This means any "system" can be removed in its cage and bolted into any 
other fitting
- Any system can be replaced in 5 minutes - 1 hour
- Any system can be independently replaced and serviced
- A modular engineered system can be put upside down and shaken and will 
always run ! Knockdowns have 0 impact.
- Building for 100 hp systems and 500 hp engines mean the shafts are big 
and will never fail, distort, and any part can be upgraded whenever
- Building it big means all system run slower and thus generate much 
less noise and heat
- Building it heavy means nothing needs to be in stainless, as std 
engineering steels in thick cross sections will never fail due to corrosion
- Std engineering steels are very cheap ! (compared to stainless)