Chain Crew · Line to Gain · NFHS

Chain Mechanics

Positioning and responsibilities for the down box operator and chain men — marking the line to gain, first down measurement, and proper chain crew protocol.

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Chain Crew Overview

The Line-to-Gain Crew

The chain crew marks the line to gain and measures first downs. A properly positioned, disciplined crew keeps the game moving and allows officials to focus on play.

Down Box Operator

Planted at the line to gain, the down box operator holds the marker that determines whether the offense gained a first down.

  • Hold line to gain
  • Mark first down spot
  • Moves on official signal

Chain Men

Two chain men hold the 10-yard yardage chain that keeps the down box properly swung upfield to its correct first-down spot.

  • Hold the 10-yard chain
  • Stay off the field
  • Keep chain taut

First Down Protocol

Measuring a first down requires the crew to move only on the signal from the covering official, keeping the measurement accurate.

  • Move on signal only
  • Hold at spot
  • Give and take chain
Chain Crew Responsibilities

Key Duties

Critical responsibilities for each member of the chain crew to keep the game accurate, fair, and moving.

Down Box Operator

  • • Stand on the sideline at the line to gain, holding the down box upright so it marks the exact spot.
  • • On a first down, move the box forward only on the signal from the covering official, never on your own judgment.
  • • Keep the down number visible and updated after each play.
  • • Stay off the field of play and out of the path of the sideline official and players.

Chain Men

  • • Hold the 10-yard chain taut so the down box operator swings correctly upfield to the first-down spot.
  • • Keep the chain parallel to the sideline and off the field of play.
  • • Move the entire length of the chain upfield only when signaled, keeping it level.
  • • On a measurement, remain still until the official has taken the measurement.

Measuring a First Down

  • • When the ball comes to rest near the line to gain, the covering official signals for a measurement.
  • • The chain men give the down box operator the chain and yardage so the box can be swung to the new forward spot.
  • • The down box operator plants the marker, defining the first-down spot for the remainder of the series.
  • • The crew never adjusts position until the official signals — this protects the accuracy of every measurement.
Chain Crew Basics

Common Questions

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Download the complete chain mechanics guide, including down box operator duties, chain man positioning, and first down measurement protocol.

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