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Chapter 4.1

Length of Sloped Wall of a Facility »

Safe and practical measurement of the length of sloped wall in a storage facility is difficult, particularly when the facility is full. The preferred option is to consult plans or design schematics for the facility. If these are unavailable, the alternative is to make a direct measurement once the facility has been emptied. When using this strategy take special care to minimize risk of damage to the liner, particularly if the liner is synthetic. Damage to the liner can result in leaks and can be costly to repair. This measurement will be used to estimate the height (depth) of manure, the width and length of the facility base and the width and length of the manure in the storage facility.

Length of Freeboard »

The length of freeboard can be measured using a weighted rope or tape measure.

Estimating Height (Depth) of Manure in a Storage Facility

The height of manure in a facility is calculated using the mathematical principles for a right-angled triangle (Figure 4.1.12). The height (depth) of the manure is calculated using the freeboard length measurement, the slope angle of the wall reported in degrees and length of the sloped wall.

The slope of the wall is determined by subtracting the measured slope angle from 90 ° . The ‘cosine’ of the calculated angle from the slope, referred to as ‘cosine’ factor, is provided in Table 4.1.5.

Calculated slope angle = 90 ° - measured slope angle

The height of manure is calculated as:

Manure height = cosine factor of calculated slope angle x (length of sloped wall – freeboard)

Table 4.1.5 ‘Cosine’ Factor 1 for Measured Slope Angles (degrees)

Measured Angle 2 (degrees)

‘Cosine’ Factor of Measured

Angle

Measured Angle (degrees)

‘Cosine’ Factor of Measured Angle

5 0.9962 50 0.6428 10 0.9848 55 0.5736 15 0.9659 60 0.5000 20 0.9397 65 0.4226 25 0.9063 70 0.3420 30 0.8660 75 0.2588 35 0.8192 80 0.1736 40 0.7660 85 0.0872 45 0.7071 90 0.0000

1 This table provided the ‘cosine’ value for various measured angle degrees.

2 Round the measured angle off to the nearest value in the table or take the ‘cosine’ of your measured angle to determine the appropriate angle ratio for the calculation.