Litter Carry Team Size, Rotation, and Effort

A litter takes six carriers on anything but easy ground, and six carriers cannot carry for an hour. The pace used in planning -- often under one mile per hour on moderate terrain, and far less on steep or brushy ground -- is a SUSTAINED pace that already assumes rotation, so the staffing has to provide the rotation that pace assumes. Two teams alternating gives each team a fifty percent duty fraction, which is roughly what a long carry-out requires, and a very steep or very long carry may take three. The person-hour total is the output that drives the radio call. A carry that sounds like an hour and a half back to the trailhead is, once the arithmetic is done, twenty or more person-hours -- most of a mutual-aid team -- and knowing that at the start rather than at the halfway point is the difference between a controlled extraction and a stalled one. A 1.5 mile carry at a sustained 1.0 mph with six carriers per litter, two teams alternating and rotating every ten minutes, plus a medical attendant and a navigator, is ninety minutes, fourteen people, twenty-one person-hours, and nine rotations. Steepen the ground so the sustained pace falls to half a mile an hour and the time doubles, the person-hours double, and a third team is probably needed. The pace is by far the most sensitive number here and it is the one that gets guessed optimistically. A planning aid; the incident commander, the team's own condition, and the terrain govern.

carry_time_hr = distance_mi / pace_mph; teams_needed = ceil(1 / duty_fraction); carriers_needed = carriers_per_litter x teams_needed; total_personnel = carriers_needed + support_personnel; person_hours = total_personnel x carry_time_hr; rotations = carry_time_min / rotation_interval_min.

Litter carry staffing from a sustained pace that already assumes rotation, with the team count as the reciprocal of the duty fraction, by name; standard search-and-rescue planning practice. The pace, duty fraction, and rotation interval are entered rather than bundled. A planning aid; the incident commander, the team's condition, and the terrain govern.

Division and multiplication on the team's own distance, pace, and staffing assumptions.

Estimate. AHJ and licensed professional govern.

Field names used by the API: distance_mi, pace_mph, carriers_per_litter, duty_fraction, rotation_interval_min, support_personnel, carry_time_hr, teams_needed, carriers_needed, total_personnel, person_hours, rotations

• Sustained pace already assumes rotation; often under 1 mph on moderate ground and far less on steep or brushy terrainSAR planning practice
• Duty fraction teams = ceil(1 / duty fraction); two alternating teams give each 50%SAR planning practice
• Most sensitive input halving the pace doubles both time and person-hours and usually adds a teamSAR planning practice