T-Pain Is On A Boat: Re: [Electric Boats] Electric Goliath ASD Tug vs. Goliath Diesel Tug

Saturday, May 31, 2014

Re: [Electric Boats] Electric Goliath ASD Tug vs. Goliath Diesel Tug

Thank you for the suggestion Matwete, However, I have found that prop guards specifically do nothing for the thrust. With a Kort nozzle or a Rice Nozzle, the thrust and speed of the boat are drastically improved. They report as much as 30% over an open prop in a Bullard pull, and 17% out in open water. increases in thrust, speed, maneuverability, etc.

There is another one I was looking at, but they would not even return my request for info. If I wasn't looking for 144" and 6,000 SHP, they were not interested.

Will be keeping my options open for now. Starting to lay the keel in the next few weeks.

Aero_Dan

----- Original Message -----

From: matwete matwete@comcast.net [electricboats]

To: electricboats@yahoogroups.com

Sent: Friday, May 30, 2014 10:10 PM

Subject: RE: [Electric Boats] Electric Goliath ASD Tug vs. Goliath Diesel Tug

Not quite a kart nozzle but mine has been running with a Propguard now for years or so...plenty of thrust anyway and it look badass...

http://www.propguard.net/

Sent from my Verizon Wireless 4G LTE smartphone

-------- Original message --------

From: "dhennis@centurytel.net [electricboats]"

Date:05/30/2014 4:39 PM (GMT-08:00)

To: electricboats@yahoogroups.com

Subject: [Electric Boats] Electric Goliath ASD Tug vs. Goliath Diesel Tug

OK, Here I am... Since I am actually new at the starting of a thread, I am just as green as many others. Here is a brief background - I am a seasoned builder of many things "alternative". A couple years ago, I bought a set of Glen-L Goliath plans, I intend to build in steel. I have built Glen-L designs since my first started in late 1969. It has been my experience with their designs, that Glen and Ken are pretty sharp Nautical Engineers, and their specs., including power, are spot-on. I have experienced under-powering, and failed to plane. I have experienced overpowering, and witnessed my best friend in H.S. actually inadvertantly do a 360°, mid-air barrel role with the 8' PeeWee.

So here I am today - I am a good welder and fabricator. I like steel, although if I were 3 times as rich as I am, I would probably build it in AL, and never take it near the ocean. (my qwerks)

I have seen there is a need in my area, for a HD work tug that is environmentally friendly as well as ruggid enough to habdle the rigors of dock towage and maintenance on the lakes. I would like to build this tug to meet that void in the fleet. I thought about buying a Ranger (tm) tug, but at around the $50,000 mark, it is simply to expensive to "experiment" with. So, I progress...

I have done an exhaustive research of powerplants, and am most inclined to go electric, with a small deck mounted genset for range extension. With me so far?

I am exploring the possibility of building a mini steerable "L-drive". I have an engineering background, and believe it is possible. I just want to make sure I have sufficient power (thrust) to tow floating objects (docks, houseboats, and the like), of up to approximately 10 times the DWT (dead weight tonage) of the tug. In considering Eric's data from the other thread, I am still left with a slight variance between what Glen and Ken designed, at Glen-L, and what you-Eric, have suggested. I know about the reduction in rated H.P. that is figured in when converting a design from ICE to Electric. However, I do not want to build without some reserve power, and find I need to dump the power plant and try to botch in a bigger one. I know from experience that a vehicle with a "little bigger than designed" motor, translates out to less strain on the motor and longer life.

I also wondered if anybody reading these threads had any experience with a Kort nozzle on their EB (electric boat)? In my research, it would seem, that the addition of a Kort nozzle will increase efficiency in bollard pulls, as much as 30%. I suspect this will have a ripple effect to the battery life per charge, and the required throttle setting to achieve a desired setting.

So what does anybody, (including Eric) think? Can I expect a 30% or less increase in the figures for power and duration?

Thanks for all the help in advance.

Aero_Dan

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