Drag Quotient

To all Concerned,

I have received several comments that indicate folks believe me to be using this forum to perhaps endanger the environment.

I would NOT like this to discourage anyone from assisting me.

Here is a clarification .

My byline of "eat more fish, save a cow" is mostly for humor.

My net designs and nets are now built for scientific purposes only as I no longer cater to the commercial sector.

Over the years I have designed many nets for sea food as well as nets to protect crops from birds, nets to capture endangered animals for THEIR protection and safety nets for construction workers.

Over the years my nets have fed countless hundreds of thousands of people from North and South America, New Zealand to Finland, to Japan , China and Russia. I do not apologize for this. It is what I did to support my family.

In later years I have designed nets for 3rd world nations in Asia and Africa to raise fish and capture fish ON A SMALL FAMILY SCALE , so they would not starve. This was done through several international organizations and was all donated time and effort.

No offense, but how much time have any of those concerned persons , donated to helping underpriviledged persons in the world with THEIR skills?

I now design nets SOLELY for scientific research. My skills, (or what is left of them after a severe cerebral stroke 8 years ago), are used for SAVING fish and their environment. I work on projects that involve numerous species of endangered fish and other marine life.

Back -in-the-day...... I fished in all the 7 Seas of the world and have seen first hand the rape and pillage of our oceans. I created some of the gear used to do this..........but now I am making amends in my own way.

I am at present working on several projects , one of them is to test benthic organisms in 9,000 feet of water ......they have a concern that polution has reached into these depths and my gear is needed to quietly and economically assist in finding out if these fish are affected.

I'll make less money on this project than most folks here make on a one day consulting trip. I do it because it is the RIGHT thing to do.

Since my stroke I am left with some missing information. This forum allows me to ask engineers to assist me in 'recovering' that data that was destroyed when 3 blood vessels ruptured in my head 8 years ago.

By assisting me , you are NOT contributing to the demise of marine life but helping to rebuild it!

Curiously enough, I wonder how many engineers working for chemical companies or manufacturing companies that pollute our air and water......are also asking questions here? Is anyone questioning their motives?

This is an engineering forum. Lets keep politics out of it. There are thousands of other forums where these political issues can be discussed. CR4 is a godsend to someone like myself who at one time had a very "sharp" mind but now has pockets of dead space.

Hope all is clear now and I still say.......save a cow, eat more fish!

......and no one has better recipes for cooking fish than the Cajun folks!

__________________
Save a cow, eat more fish!

1/2" Steel Cable is .38 pounds per foot, to figure out how much pull you will see by just lowering the rope. Assume the depth is 1,000 ft the angle is about 30 deg on average, and slightly curved, the length would be about 2,134.84 feet of cable pulling on the boat, (200 lbs weight removed) or 811.24#.

5/8" Steel Cable is .59 pound per foot, so with the same assumptions, 1,259.55#

I think you may be able to extrapolate your answer based on the actual depth from this formula...

Good luck

Thank you very much.

Yes, i can extrpaolate from this and make a formula.

What I would also ask is , what increase in the Bollard pull is there when these lengths are moved forward at 2mph and 4 mph?

the angle will change some but shoud, not exceed 30 deg at 2mph and 38-45 deg at 4mph.

this is just an average from past work with approx. the same cables but at much lesser depths.

any ideas on this?

Thank you again for whatever you can come up with.

netmaker

To be honest, I don't know how to figure in the speed of the boat. My thoughts on that were if the reel was free wheeling then as you increased the speed of the boat, wouldn't you increase the rate of release on the cable?

If you want me to re-calculate for 45 deg. I will if it will help.

Thank you Lab,

I think if I have the weights I can find a formula for plugging in the speed .

Going to 45 deg. will be on the top end of where this rig will be. It will settle in somewhere around 30-35 deg .

Your calculations are going to get me started in the direction I need. Now i have to look at what additional drag is placed on the cable (hence the winch and block) when we add velocity to the weight of the cable.

There are so many variables in this. I just need an estimate of what the bollard pull will be when we crank up the boat to 4 mph (knots).

Thank you for this info so far. I'll see if i can make it work and in the mean time maybe someone with another angle on this type problem will jump in here.

Merci beaucoup mon amis.

netmaker