Safety and occupational healthSH-005

Hazardous crane motion remained available during maintenance

Lone Star Industries · Maryneal Quarry and Mill, Texas, USA · 1997

Use this record when

The decision this case can inform

Use this record when a maintenance task proposes powered positioning, radio-directed movement, or work between components that can close together.

Evidence scope

Final MSHA fatal-accident record. It establishes the causal role of available motion, command ambiguity, and deficient task planning; it does not authorize energized maintenance.

Source-supported facts

What the public record actually establishes

4 sourced points
  1. F1

    The crane remained powered and the trolley was not blocked while the crew respoolled cable.

  2. F2

    The two hoist drums were about six inches apart, creating a severe draw-in point.

  3. F3

    The crew had no agreed command sequence, and a radio instruction was misunderstood or incorrect.

  4. F4

    MSHA identified limited task experience, inadequate task training, and the absence of a written procedure among the contributing failures.

Structured interpretation

Facts and reported results are kept separate from the lesson a plant may choose to test.

01

Operating context

A crew respooling a crane cable worked on the trolley with hazardous motion available and no agreed command sequence.

02

Intervention or finding

MSHA cited failure to block or prevent motion, inadequate procedure, ambiguous commands, limited experience, and inadequate task training.

03

Documented result

A drum moved after a misunderstood or incorrect radio command and drew a worker between the drums.

04

Plant interpretation

Communication is not isolation; prevent motion unless formally controlled movement is essential and safely planned.

05

Transfer boundary

Does not authorize energized maintenance.

Before applying the lesson

Questions to verify at your plant

These are decision checks, not operating instructions. Resolve them through local risk assessment, technical review, and authorization.

  1. 01

    Can all hazardous motion be isolated and mechanically prevented before anyone enters the danger zone?

  2. 02

    If controlled movement is genuinely essential, what engineered plan defines positions, commands, abort criteria, and one person in charge?

  3. 03

    How is command acknowledgement made unambiguous in noise, poor visibility, or radio failure?

  4. 04

    Has task-specific competence been demonstrated rather than inferred from general crane experience?