Crane Hook / Lifting Sling Angle Load Calculator implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t6-136

Effect

Computation or source lookup only

Input and validation requirements

The specification exposes hazards at the zero-angle denominator, requires rejection of negative or out-of-domain angles rather than trusting raw arithmetic, and has a substantial result ambiguity if the angle reference is not enforced as measured from horizontal.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "total_weight_W": 12000,
    "weight_unit": "N",
    "number_of_legs_n": 2,
    "sling_angle_theta": 30,
    "angle_unit": "degrees",
    "angle_reference": "horizontal",
    "leg_spread_geometry": "symmetric; equal angles; centered vertical load"
  },
  "expected_outputs": {
    "tension_per_leg": 12000,
    "tension_unit": "N",
    "required_sling_rating": "not determinable from this formula alone"
  },
  "working": "sin(30°)=0.5. n·sin(theta)=2·0.5=1. T=W/(n·sin(theta))=12000/1=12000 N per leg."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche6/tranche6-results.json