Did a dream got shattered?

thats great to hear Burt! Im glad you went with your own ideas...in the end- its the ones who took the road less travelled that made the most difference...(see the peom by Robert Frost)...

btw happy B-day! You will succeed Burt- Youve done it before and will again! this is inspirational for me too...so your success becomes my success...

keep me posted... if you have any pics-- feel free to send them my way via PM

regards
Doug

 

Thank you Doug,

This website still has given me the best answers and help in the past and if possible I like to stay with this thread and see where it leads me to. Thanks Doug, I keep it in mind.
Bert

 

Bert --if it not too late --email me--i have a guy who can help you if you haven'tt started the hartley 28 build yet..he can help with scaling and he seems to know his stuff...this is doable--i completley believe that..go for the better boat--yes lead keels will work...anyway this probably has been stated many times..just thought id give you a boost if needed...you continue to impress me...
with kind regards
Doug

 

it is a long thread, but a dream can't be shattered only if you decide too.
keep it alive.
we always regret the things we didn't do, not the things we did. (well almost!)

 

Thank you Larry, It is not easy with a wife who wants me to buy a finished boat, a daughter who wants me to build an electric car instead of an electric boat and me who has to prove to myself, that the stability is not a problem at sea. But, if somebody tells me to jump of the Eifel tower, I do not just jump. But it is a lonely world and I appreciate your support and that from Tugboat (and a few others) . By next week I will have finalised the stability and righting curve, then we will know whether the suggestions from Delft and Wageningen will work. I try to do it in 3 dimensions, x,y,z, but after a full Sunday I gave it up and went back to 2 dimensions y and z only. However, because I have a twin keel, I am struggling to understand the consequences mathamatically what will happen if the hull with 2 keels 60 inches, (1,5 meter) appart, heel 30 degrees etc. With a single keel, it is easy, a piece of cake, but with a twin hull, I pulled a few hairs out. Vectors have never been my strongest point, but I will somehow make a plan.

I hope in the next two weeks to show some photo's on the motor/gearbox I am busy finalizing. Without a good working twin motor system, I may aswell not build this boat. Batteries is a matter of choice, LifoPO4 or SLAB's, also not a problem. Just to sort out the stability and I am on my way.
Thanks Larry, I truly appreciate your post.

 

ok i will shoot in the dark, since i am no designer. could you consider the average weight of the two keel, and put the number and center of gravity position in the center line? so you can calculate as if it was a center line keel.
i don't know, its probably not that the problem you face with the two keel.
anyway, again keep going, and tell your wife when the boat is done:
you see darling we just bought a brand new boat, it take a little longer to buy, but its ours. she will be delighted.

 

Thanks Larrry, I will remember.

I probably will have to calculate with vectors the resulting combined weight and forces at that angle. I am Friday on the way to Johannesburg, will only have time next week.
Bert

 

Bert-old freind--when will you know hear back from them... ??..let me know asap.. .also i loved some of the tugs (sleepboots) on the dutch boot site--what is a upduwar? there are lots of them and they look powerful--also what is a trekproef???
awesome little tugs --how powerful are they? do they use listers ?

 

for the boat im doing- what about two high torque golf cart motors..12 hp cont. each. geared 4:1 pushing two 20 x16 inch props. 36 volts each-charged by two seperate alternators running off a small deisel shaft 130 amps each??

 

Hi Tugboat, If you do not care about efficiency, because of running a diesel and alternators to power the motors, you may as well go for hydraulic motors. You can get some very powerfull ones for 250 dollar. It is easier, you just pump your oil to the motors, very reliable. Effiencey with hydraulics is about 55%. if you go for 2 x 9 KW (12 HP, you need batteries as a buffer, your 130 Ampere 36 Volt (Where do you buy them other then Lockheed or Boeing, don't they use 36 Volt in planes? I would just run the diesel and a hydraulic pump. No buffer batteries, no electro motors , no generators. But why do you want to make it complex?

In my case, I like to experiment. also I don't want noise, thus I have no diesel or hydraulics. Only solar and wind and offshore charging. Therefore I have to run on about 1,5 - 2 Kw, otherwise the LiFePO4 batteries will become 30 - 40 Kwh instead of 20 - 25 Kwh. Also, I will have a range restriction and also only with good weather and reasonable flat see. Which is about 150 days per year here.

Duw sleepboot is a tugboat which pushes instead of pulling.
Stick to your lovely tugboat, go for it.

I have no idee what listers are. ask Yipster, he probably would know or CDK. Yes it is a lovely series of Tugboats 50 of them, I would not mind any of them.
Bert

 

hi Bert- first--im not sure if the diesel I have will even start, its been outside year round in freezing weather year round for some years ...i dont trust the guy i boght it from ----I found water in the crankcase, where oil was supposed to be--and this troubles me. what if the engine is cracked?..its done and there are no other like it--not to mention trying to remove the transmission AGAIN, and the costs of that.
so then-I have a prop that wont fit another engine-since it is sized perfectly for the d318. plus its expensive as well to use BIG shafts, big bearings and everything else such as remote fuel filters, heat exchangers and pipings, large exhaust systems and on and on...and the fuel economy on a small genset is cheaper than a large big bulldozer engine.
the build costs are less because the design is now not needing heavy floor girders and bearers for the engine

and well..one reason for a D.E. system is fuel efficiency. also these ev motors are 12 hp contiuous and intermittent around 20. I cna buy larger mor epowerful ones thta run on the same amps and voltage too! easily replaced in the field and the props for these are about 500 for the pair of 20 inch props needed( isnt that prop calc a thing of beauty!!!)

But these have more torque than the same hp on gas or diesel. so i can get twin screws which allow me to have more manoevrability. i.e the vessel can be flanked!

its actually not hard to hook up alternators to a simple 10 hp air cooled tractor diesel engine then to batteries-or I could run two directly into the engines and have 2- 400 amp controls. example: if i run eight 130 amp alts. these run directly to the engines(using two 10 hp diesels) electric engines are very efficeint compared to diesels or gas. and they need no transmissions- they are direct reversing instantly- and I can gear them to 3:1 4:1 5:1 whatever i choose- using belts or chains. and a very cost effective method.since I need no tranmsisions-just a fnr control and a controler for each engine... I also like the quiet sound of a boat on water. the new air cooled diesel costs 650.00! cheap as beans. it will run four alternators costing 75 bucks each used. if i needed to i could buy a cheap Detroit deisel 4-71 for around 700.00 and run a few alternators directly off the shaft. one for each battery.
very simple. not as complex as it seems. use diodes in case of overcharging.
if i need help wiring it ill gte someone to help me find a way to run directly to the motors bypassing the batteries doing away with batts if necessary -keeping my weight low. the d318 with gear weighs a staggering 4000lbs! this is a lot in a small boat. add the shaft, the bearers etc large DO tanks water, and the weight starts to add up. this means more running costs etc....check out this link--

its a 100 hp or 75 Kw electric drive--watch the fantastic torque on this engine!!!! pushing a dutch boat- it isnt THAT complicated--runs off a genset ..
Bert--im excitedly awaiting the news on your calcs for the stability!!! forget the electric car- forget buying-- build her!!(
http://www.youtube.com/watch?v=v_nC-ebZdtU

the above link is a dutch diesel electric. note the setup of the shaft--direct drive-no transmission that i can see since high torque is devoped at low rpms.

 

Well Tugboat, the above indeed may be a good reason to consider an alternative.

Now you have to do research on the advantages of DC motors versus hydraulic. If your diesel engine is 12 H.P. you cannot expect to have 2 x 12.H.P. DC engines to run on it, except if you have a sufficient battery bank to buffer. A DC motor could have an efficiency of 90%, your cabling will be probably 95%, your alternators are probably 70% i.e. from your 12H.P. you can only expect .9 x .95 x 0.7 = 60 % i.e. only 7 H.P. spread over 2 motors.
You may have to consider a 20 H.P. Diesel at least.

The torgue of a hydraulic motor is also inredible, maximum 787 inch-pounds for USA$ 250. If you use a rotating pump, your noise is not that high. It is very simple to mount and set up.

Here is the second reason to consider an alternative

This is the third reason to consider an alternative.

I did check this website and while I was overseas, I looked at the various options there. As you know, there are 16 million Dutch people living in Holland, and one would nearly think and say, that there are an equal number of boats and yachts all over the Netherlands. I have a report of a 27 H.P. Diesel which needed to go flat out to reach the hull speed, while the 6 KW motor did the same hull speed for the same boat. Thus your idee is not a bad one. Just make sure that you have a wiring plan to charge your batteries. If you charge 3 x 12 Volt battery bank with 3 x 14.4 Volt alternators, and the generators are isolated and are floating, I cannot see why it cannot be done with 6 generators of each 300 Ampere, you have 1800 x 14.4 = 25.92KW x 60% efficiency = 15 KW is good enough for 2 x 10 H.P. DC motors
But your diesel has to be a 35 H.P. Diesel at least. Or like you said before 2 x 18 H.P.

Quite impressive, but overdone. You need not more than 15 KW for your 25 feet boat. There are 50KW DC motors watercooled for sale in the states, but cost some 28900.00 USA dollars each. I prefer the Mars motors for 450 Dollars.

Yes me too. But I have very little time at present. I collected the gears and stuff made for me, but they had an emergency repair job taken on and I have to wait for the shaft. Tomorrow I am flying to Johannesburg , thus it has to wait until next week.

that is true, it depends what electronics is used and what kind of motor is used. They may have a 300 Volt DC motor used. I personnaly would stay away from DC Voltages of > 36 Volt. At the most 48 Volt.

 

"They may have a 300 Volt DC motor used. I personnaly would stay away from DC Voltages of > 36 Volt. At the most 48 Volt."

Agreed.

The Mars is an excellent motor for your application.

-Tom

 

Here is the link, or even better type uin google "prince heavy duty hydraulic motor" and look at the 3 options

One has a choice of low revolution per mitute and 14 Gallon per minute or 12 Gallon per minute

http://www.northerntool.com/shop/tools/product_200321045_200321045

Bert