Trellis Post Spacing Load

Screen interior post tributary reactions from caller uniform transverse line load and unequal adjacent bay lengths; simplified statics excludes wire dynamics, soils/wind/design factors and does not approve trellis spacing/safety.

Description

An interior trellis post carries contributions from adjacent bays.

An interior trellis post carries contributions from adjacent bays. Unequal bay lengths change its tributary reaction.

When to use Trellis Post Spacing Load

Use this tool to screen interior post tributary reactions from caller uniform transverse line load and unequal adjacent bay lengths; simplified statics excludes wire dynamics, soils/wind/design factors and does not approve trellis spacing/safety.

Prepare vineyard measurements, dates or block records for the intended growing period. Keep weights, counts and weather observations in the stated units.

How to use Trellis Post Spacing Load and understand its results

Prepare vineyard measurements, dates or block records for the intended growing period. Keep weights, counts and weather observations in the stated units.
Enter postBayLengthsM, declaredUniformTransverseLoadNPerM, declaredAllowablePostReactionN using the field table and calculation rules, then run the tool.
Read interiorPostModelReactionsN, aboveCallerReactionLimitFlags. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
postBayLengthsM	Post bay lengths m	list of number	Required
declaredUniformTransverseLoadNPerM	Declared uniform transverse load n per m	number	Required
declaredAllowablePostReactionN	Declared allowable post reaction n	number	Required

Supply at least two positive bay lengths, positive allowable reaction and nonnegative N/m transverse load. Calculate one reaction per interior post and flag values strictly above the caller limit.^[1]

interior reaction = transverse line load × (left bay + right bay)/2

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
interiorPostModelReactionsN	Interior post model reactions n	list of number
aboveCallerReactionLimitFlags	Above caller reaction limit flags	list of number

json

{
  "input": {
    "postBayLengthsM": [
      2,
      3
    ],
    "declaredUniformTransverseLoadNPerM": 10,
    "declaredAllowablePostReactionN": 20
  },
  "output": {
    "interiorPostModelReactionsN": [
      25
    ],
    "aboveCallerReactionLimitFlags": [
      1
    ]
  }
}

Limitations and assumptions

Wire dynamics, soil, wind factors and engineering design are outside the statics screen.

Numbers and computed results must be finite; overflow produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Trellis Wire Tension Estimate: Infer ideal parabolic span tension from declared uniform gravity line load and measured small sag, retaining horizontal/endpoint forces; not generic stress or real catenary/temperature/anchor capacity certification. For a complementary task, use End Post Anchor Angle Leaning: Balance declared horizontal end-wire overturning moment with supplied ideal anchor lever height/angle and tension limit; ignores post lean, foundation/soil capacity and transient loads, not a construction/safety recommendation.

References

Trellis Post Spacing Load — tool.io

Similar or alternative tools

Trellis Wire Tension Estimate
Infer ideal parabolic span tension from declared uniform gravity line load and measured small sag, retaining horizontal/endpoint forces; not generic stress or real catenary/temperature/anchor capacity certification.
End Post Anchor Angle Leaning
Balance declared horizontal end-wire overturning moment with supplied ideal anchor lever height/angle and tension limit; ignores post lean, foundation/soil capacity and transient loads, not a construction/safety recommendation.