# Sailors wrong for thousands of years?

Discussion in 'Sailboats' started by backyardbil, Feb 7, 2011.

1. Joined: Apr 2009
Posts: 897
Likes: 37, Points: 0, Legacy Rep: 442
Location: usa

### warddSenior Member

no reason the mast couldn't be the shaft

2. Joined: Nov 2006
Posts: 233
Likes: 4, Points: 0, Legacy Rep: 56
Location: Norwich UK

### WindmasterSenior Member

Vertical Axis - Nice idea, but doesn't do the job.

From time to time, the vertical axis idea gets mentioned. The main attraction, being of course, that you don't need to orient it to the wind.
However, there is no case where a boat, or indeed a land vehicle has ever been able to travel directly to windward with one, and without this ability, the main attraction and indeed advantage of a rotary sailing power is lost.
It's not difficult to see why a vertical axis setup does not work directly to windward when you consider that the blade on a horizontal axis machine may achieve a lift to drag ratio of as much as 50 to 1 (50 times the lift for one of drag). This makes for super efficiency in that the rotating force (which we use to power the boat) could be 50 times greater than the drag which is tending to hold the boat back. By contrast, the drag of a vertical axis arrangement is considerable. True, they have been used successfully on land-based power generation turbines, but on a fixed base system the drag is of no importance since it does not matter how much you push the ground - it's not going to have any negative effect!

Last edited: May 1, 2011
3. Joined: Nov 2009
Posts: 135
Likes: 27, Points: 0, Legacy Rep: 359
Location: San Francisco, CA, USA

### Dave GudemanSenior Member

Has anyone ever tried? I'd be interested to know more about any such attempts.

I don't follow this. The force that would be applied to the wheels to make the land vehicle move forward would be determined by the gearing; not directly by the lifting force on the blades. Unless the drag is so much that it is causing the wheels to lose traction, the only effect is that you require a slightly lower gearing which would cause the vehicle to move a bit slower.

The case is different on a boat, of course.

4. Joined: Nov 2006
Posts: 233
Likes: 4, Points: 0, Legacy Rep: 56
Location: Norwich UK

### WindmasterSenior Member

The only attempt I have seen is one of the entries in the landcart "wind energy events" which have been taking place in Holland and Denmark in the last few years http://www.windenergyevents.com/Race2008/index.html I have seen some video footage of one of the entrants with a vertical axis turbine. The shot shows a team of people pulling a rope to get the rotor up to speed before (presumably) setting it on its way directly to windward, but there is no view of it actually proceeding in the required direction. That's the only time I have seen any evidence of an attempt, and since I am sceptical that it would work, I don't want to spend a lot of time and energy on it myself. But anyone else is welcome to try!

On the point about the gearing, yes, that is true that you could gain mechanical advantage by gearing down. However, you are still facing a pulling match between the drag holding you back and the rotating force which you want to use to push you forward. You would have to gear down a whole lot, which would (IMHO) result in creeping forward minimally in a very impractical way. In the case of a boat, it is not so very different actually.

5. Joined: Jan 2011
Posts: 97
Likes: 3, Points: 0, Legacy Rep: -36
Location: Vancouver Island BC

### Jack HicksonNew Member

Tried vertical axis on a wind generator once . Useless. The non driving one was strictly drag. With a blade, both provide power full time.

6. Joined: Apr 2008
Posts: 6
Likes: 0, Points: 0, Legacy Rep: 10
Location: amsterdam

### hawkerdonkeyJunior Member

Azipod thruster

Hello to all,

I've very much enjoyed reading the banter on this particular subject and my \$0.05 would go to this beauty:

One Rebuit Retractable horizontal drop down
Type Wartsila Lips CS1500-250 MNR
Power Rated 1550 KW
Motor Speed 1000 rpm
Prop. dia. 2300 mm
Stem Length
Drive Horizontal
Motor voltage 690
Status Rebuilt
Class Lloyds
Mounting Under water mountable
Available now
Warranty none
Includes motor and control gear, couplings
Installation drawing available
Lloyds cert available

He has a lot of other heavy metal too. Connected to a slow turning, correctly calculated windmill (blade-Tip ratio et al) and plant it at the back of something like this for fuel conservation purposes http://www.jameslist.com/advert/88168/for-sale-cantieri-di-pisa-30-s

All within budget and delivered before the deadline

While we're at it, I still haven't found a marine application to these yet (jet?) but at the tip of the blades, on a calm day should cause a bit of a stir I recon.

http://www.tecaeromex.com/ingles/RH-i.htm

Toodlepip,

Honkey!

7. Joined: May 2011
Posts: 25
Likes: 0, Points: 0, Legacy Rep: 10
Location: Ft. Rucker, Al.

### nate teachHow hard can it be? :/

so what happens when the wind is coming from behind you?

8. Joined: Apr 2008
Posts: 6
Likes: 0, Points: 0, Legacy Rep: 10
Location: amsterdam

### hawkerdonkeyJunior Member

Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.