Irrigation System Planning for Wheel Lines and Big Guns

1
Side roll / Wheel roll Sprinklers
2
Layout Consideration

• Obstacles
• Fences
• Power lines
• Out buildings
• Ditches
• Roads
• Wind

3
Example
Fence
Power line
Ditches
Buildings
Road
4
Irregular Field Shape
5
(No Transcript)
6
Slope

• With the slope vs. Cross slope
• Laterals are generally laid out perpendicular to
  the slope

7
(No Transcript)
8
(No Transcript)
9
Set Times

• Convenient set times
• 23.5 hrs
• 11.5 hrs
• 7.5 hrs
• Allows ½ hour drain time
• 7.5 hr not popular . One move allways in the
  dark

10
Lateral set sequencing

• Irrigate every move across the field roll back to
  the front and start again
• Skip irrigate every other move irrigate the
  skipped moves on the way back
• Irrigate every move across the field second time
  use a offset pipe. Alternate back and forth

11
Uniformity

• Affected by
• Base Pressure
• Pressure variation
• Overlap
• Application Rate
• Wind

12
Base pressure

• Match spacing to pressure
• Rule of thumb
• 45 to 65 psi 40x60 and 40x50
• 35 to 45 psi 30x40 and 40x40
• 25 to 35 psi 20x30 and 30x30
• Drains may not operate properly under 24 psi

13
Pressure Variation

• Affected by
• Elevation difference
• Up and down slope vs cross slope
• Mitigate with flow control nozzles or pressure
  regulators
• Friction loss
• Pipe sizing
• Limit pressure variation to 20 of design
  operating pressure

14
Overlap
Rule of Thumb 50 along lateral 65 between
laterals
Example 40x50 spacing Sprinkler diameter would
need to 77
15
Application Rate

• Too small wind problems
• Too Large runoff
• Match to soils and Irrigation interval

16
(No Transcript)
17
Wind

• Causes
• Poor uniformity
• Fine sprays
• High pressures
• High trajectory
• Structural damage

18
Affects of wind
19
(No Transcript)
20
Wind Solution

• Low trajectories
• Low pressure
• Course sprays
• Offsets
• Braces

21
Alternate sets
22
Example of multiple passes
23
(No Transcript)
24
(No Transcript)
25
Maintenance

• Nozzles
• Gaskets
• Drains
• Levelers
• Springs/rotation

26
(No Transcript)
27
(No Transcript)
28
Big Guns or Traveler Sprinklers
29
Cart Style
30
Solid Set
31
Hose Reel
32
Layout

• Hose drag
• Solid set
• Rectangular vs. triangular

33
Typical hose drag layout
Traveler direction
Travel lanes
Connection to main
Up to ¼ mile (1320)
Buried or Portable main line
34
Solid set
35
Solid set layout
36
Layout options
Triangular layout
Rectangular Layout
37
Layout for wind
38
Trajectory angle

• Optimization of pattern uniformity
• Minimize wind drift
• Maximize radius of throw
• Best drop condition

39
Application Rate

• Match to soil
• Runoff
• Sealing

40
Pressure

• 60 psi minimum
• Why
• Throw distance
• Stream breakup
• Crop and soil damage

41
Riser Assembly

• Vertical
• Stable against vibration
• Low turbulence
• Protected from animals and machinery

42
Thrust

• Causes
• Tipping
• Vibration
• Fatigue and damage to joint
• Solution
• Aluminum tripod
• Concrete block
• Post
• Swing elbow

43
Concrete support
44
Tripod Support
45
Swing Elbow detail
46
Stability

• With a stable riser
• Drive arm works properly and increases uniformity
• Vibrations are dampened protecting pipe
• Stream throw radius is maximized giving greater
  coverage

47
Safety

• Big flow, lot of pressure can do damage to human,
  animal or infrastructure.