Stretcher Clearance in Narrow Passage Checker
Actual straight lateral envelope clearance only versus qualified caller margin. Turns, vertical clearance, patient/restraints, rescuers and actual transport safety external; not passage traversal approval.
Description
Stretcher width clearance compares a measured passage opening with the actual transport envelope.
Stretcher width clearance compares a measured passage opening with the actual transport envelope.1
A straight lateral margin does not account for turns, vertical clearance or the complete carry arrangement.
When to use Stretcher Clearance in Narrow Passage Checker
Use this tool to obtain signedWidthClearanceMeters, signedClearanceMinusCallerMarginMeters from the supplied records using the stated calculation. Establish the survey or observation scope, reference frame, units and independently applicable calibration or qualified plan.
How to use Stretcher Clearance in Narrow Passage Checker and understand its results
- Establish the survey or observation scope, reference frame, units and independently applicable calibration or qualified plan.
- Enter actualPassageClearWidthMeters, actualStretcherEnvelopeWidthMeters, callerQualifiedRequiredLateralMarginMeters, using the field meanings and rules below, then run the tool.
- Read result.signedWidthClearanceMeters, result.signedClearanceMinusCallerMarginMeters. Use the units and sign conventions below, and review any unknown records separately.
- Correct any reported input issue and run again. Before using a successful result, check the stated units, signs, reference scope and observation coverage.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| actualPassageClearWidthMeters | Actual passage clear width meters | number | Required |
| actualStretcherEnvelopeWidthMeters | Actual stretcher envelope width meters | number | Required |
| callerQualifiedRequiredLateralMarginMeters | Caller qualified required lateral margin meters | number | Required |
Require positive passage and stretcher-envelope widths and a nonnegative qualified lateral margin, all in metres. Subtract envelope width from passage width and then subtract the required margin. Negative values remain signed results. No turns or other dimensions are checked.
clearanceMeters=passageWidth−envelopeWidth; marginDifferenceMeters=clearanceMeters−requiredMargin Use the matching field units and the exact boundary, ordering and reference rules above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Qualified observed calculation or explicit reference | object |
| result.signedWidthClearanceMeters | Signed Width Clearance Meters; preserve the subtraction order and sign defined in the mechanics | number |
| result.signedClearanceMinusCallerMarginMeters | Signed Clearance Minus Caller Margin Meters; preserve the subtraction order and sign defined in the mechanics | number |
{
"input": {
"actualPassageClearWidthMeters": 1,
"actualStretcherEnvelopeWidthMeters": 0.8,
"callerQualifiedRequiredLateralMarginMeters": 0.1
},
"output": {
"result": {
"signedWidthClearanceMeters": 0.19999999999999996,
"signedClearanceMinusCallerMarginMeters": 0.09999999999999995
}
}
}Limitations and assumptions
The actual observation coverage, calibration and qualified plan determine applicability. A numerical result does not establish survey accuracy, route suitability, atmosphere conditions or equipment adequacy beyond the declared comparison.
Missing required fields, unknown fields, wrong types and violated rules return input issues. Numeric values and outputs must be finite. Extremely large composite outputs are rejected.
Alternative or Complementary methods
For a related step, use Pitch Headroom Clearance Checker: Pitch headroom is a measured clearance requiring user, equipment and passage context. For a complementary comparison, use Cave Rescue Carry Out Time Estimate Calculator: A rescue carry-out inventory combines qualified carry and transfer durations.
References
Similar or alternative tools
- Pitch Headroom Clearance Checker
Pitch headroom is a measured clearance requiring user, equipment and passage context.
- Cave Rescue Carry Out Time Estimate Calculator
A rescue carry-out inventory combines qualified carry and transfer durations.