Phase 1 Rope Screening Protocol

The RampWarden Phase 1 Rope Screening Program is designed to compare candidate aircraft tie-down ropes under a controlled static loading protocol. The goal is not to certify a rope for aircraft use or select a RampWarden rope product. The goal is to create a consistent educational screening method that helps pilots understand how different rope constructions behave under load, after wet conditioning, and after a lightly preloaded rope is exposed to water.

Why the Rope Is Tested as an Assembly

Each rope sample is tested as a real tie-down assembly rather than as a bare rope section. The test configuration uses a bowline-to-bowline rope assembly connected between two fixed anchor points. This matters because an installed aircraft tie-down does not move only because the rope body stretches. Total movement also includes knot seating, fiber bedding-in, constructional settling, and other assembly effects.

For that reason, the Phase 1 workbook separates two important measurements: gauge-section elongation and ring-to-ring elongation. The gauge section is measured from marks placed on the straight loaded body of the rope, away from the bowlines. This is the best estimate of true rope-body stretch. The ring-to-ring measurement captures the total installed assembly movement between the anchor points.

Load Schedule

The official load schedule begins with a 10 lbf baseline. The rope is then loaded through fixed static steps to 500 lbf. Each intermediate step is held long enough to allow a controlled reading, while the 500 lbf peak step receives a longer hold. After the peak load, the assembly is returned to 10 lbf and then measured again after a 10-minute rest period.

Dry and Wet-After-Dry Cycles

Each rope is tested through four primary cycles: Dry Cycle 1, Dry Cycle 2, Wet Cycle 1, and Wet Cycle 2. The dry cycles are completed first without untying the bowlines between Dry Cycle 1 and Dry Cycle 2. This helps show how much movement changes after the assembly has already been loaded once.

After the dry cycles, the rope assembly is wet-conditioned by full water submersion for approximately 12 to 18 hours. The rope is then allowed to drip briefly before wet testing begins. Wet Cycle 1 is started shortly after removal from water, and the bowlines remain tied through both wet cycles. Keeping the knots tied helps preserve the assembly condition and makes the repeated-cycle comparison more meaningful.

Supplemental Wet10 Tension-Drop Test

Phase 1 also includes a supplemental Wet10 test. This test is designed to observe a practical ramp concern: a pilot may tie a rope with modest preload, the rope may later get wet, and the line tension may fall. If enough tension is lost, the tie-down can develop slack before the next wind event.

For the Wet10 test, the rope is installed on the static load rig and brought to a 10 lbf baseline tension. Water is then poured onto the loaded line while the tension reading is observed. The primary measurement is the change in tension from the 10 lbf starting point after wetting.

What the Workbook Records

The Phase 1 workbook records rope construction, diameter, dry and wet weight, minimum breaking strength, estimated wet-and-knotted strength, wet-and-knotted working load at selected safety factors, Wet10 tension-drop behavior, and qualitative handling notes such as stiffness, visible deformation, knot stability, ease of untying, wet handling, and any unusual behavior observed during loading.

For each rope, RampWarden creates the same chart set: gauge elongation percentage, ring-to-ring elongation percentage, gauge elongation in inches, estimated knot and assembly settling, a stacked elongation mix chart at 500 lbf, and Wet10 preload-retention comparisons. Keeping the chart set identical across all ropes makes it easier to compare candidates visually and reduces interpretation bias.

How the Results Will Be Used

The Phase 1 results are used to explain rope behavior, not to certify a universal winner. A useful aircraft tie-down rope should show controlled elongation, repeatable behavior across cycles, manageable wet performance, limited permanent set, stable knots, useful preload retention, and practical field handling. A rope that is too stiff may transfer more load into the aircraft and anchor system. A rope that stretches too much or loses too much preload when wet may allow excessive aircraft movement or slack. Phase 1 is designed to help pilots understand these tradeoffs.

Phase 1 is therefore an educational screening program, not a final product decision. Selected rope families from this work can advance to Phase 2 dynamic and snubber testing so pilots can better understand how static behavior compares with gust-like loading, recovery, and slack formation.