Most of the larger agriculture operations around here use a single sprinkler system suspended on large wheels which they move during the day with a small gasoline or diesel powered tractor type device. [link]

Since most farmland is fairly flat I see no reason why the wheels suspending the hose segments can't be powered and made to roll using only the pressure of the water itself by causing the wheels to become off-balanced.

The wheels themselves are redesigned as tubular to accommodate water within them.
One way valves insure that only one upper quadrant at a time fills with water. Each quadrant consists of valved segments.
As the wheel begins to roll the lower valve of each quad opens and moving water pressure from the main line evacuates any water below the mid-line of the hub.
A timer, (also powered by water pressure) controls the speed at which the wheels turn while simple lateral-stress-controlled valves ensure that any one wheel turns no faster than its neighbours.

Sprinkler heads are elevated between the wheels and connect to the main line on a counter-balanced swivel to maximize distance of spray.
-- 2 fries shy of a happy meal, Sep 12 2020

Water Wheels. https://www.google....7yOKZTy-gTgwrCYCQ61
[2 fries shy of a happy meal, Sep 12 2020]

Around here... https://goo.gl/maps/hYYCBc6bU9EHgDBBA
For example... [neutrinos_shadow, Sep 14 2020]

I think you would get better efficiency with a small turbine using the water flow; either a purely mechanical link to the wheels (efficient), or a small electric generator (convenient).
Those "big wheel" rolling pipe things are weird. Pretty much all centre-pivot around here (some linear variants, some large impact-types, some "normal" rotating-arm types...).
-- neutrinos_shadow, Sep 13 2020


Where's "around here"?

I had considered using a generator but I try to whittle devices down to the smallest number of moving parts and it seemed like making the wheels themselves the motive power using nothing but valves would last for a very long time and require almost no maintenance.
-- 2 fries shy of a happy meal, Sep 14 2020


// last for a very long time and require almost no maintenance. //

But then, how do you gouge the purchaser for spares and repair and callout fees ?
-- 8th of 7, Sep 14 2020


Where does the water go? It seems like you'd over-water the plant near the wheels and cause the wheel ruts to be muddy. According to one site: "New installations should be fitted with a 'dry-wheel pack' (half-throw sprinklers on solid drops or boombacks) to keep water off the wheel track."

I like the idea to keep it simple by having the propulsion at the wheels, but to keep the ruts dry, I think you might be better off converting water pressure to mechanical movement someplace far away from the wheels using a system described by [neutrinos_shadow].

Or to make it really easy to see how it works: just use spinning arms from a "tractor sprinkler", and have those turn a long thin drive shaft that travels parallel to the pipe? There would of course be a large gear ratio to drive the wheels slowly from this.
-- scad mientist, Sep 14 2020


//Where does the water go? It seems like you'd over-water the plant near the wheels and cause the wheel ruts to be muddy.//

The water temporarily pumped into an upper quadrant rejoins the mane line it came from, before it reaches horizontal, fed by gravity and the, (I'm not sure what the word for it is... negative pressure I guess) of the rushing water in the main line.

Water would only leave by way of the sprinkler heads and the ground would stay just as dry as with conventional systems... you just wouldn't have to tend it as it passively walks the length of your filed and back like one of those autonomous strand-beasts but water powered instead of air.

No polutents. No maintenance. No fuel consumption. Way less work.
This should have already been a thing like back in the twenties.
-- 2 fries shy of a happy meal, Sep 14 2020


<< inserts photo of guy's water wheel he installed off of a small stream near a highway for no apparent reason >>

I wish more people thought like that.
-- reensure, Sep 14 2020



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