NCCCO Drill Rig flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Allowable soil bearing pressure

The maximum pressure soil can support without excessive settlement or shear failure. Pad area equals outrigger load divided by this value; soft fill and backfill require larger pads or matting.

Minimum approach distance

The closest a rig, boom, or load may come to an energized power line. It is voltage-dependent: 10 feet for lines up to 50 kV, increasing at higher voltages.

Competent person

A person capable of identifying existing and predictable hazards and who has authority to take prompt corrective action. Required for excavation, scaffolding, and many site safety decisions.

Utility locate ticket

A request to the regional one-call service that marks buried utilities before excavation. Treat unmarked ground as containing a hazard until proven otherwise.

Spoil containment

Control of drill cuttings, slurry, and contaminated soil so they do not enter storm drains or waterways. Includes berms, liners, and vacuum recovery.

Level before mast raise

The rig must be leveled within the manufacturer's tolerance, usually about one degree, before the mast is raised. Outriggers must be set on competent, stable pads.

Wire rope removal criteria

Rope is removed for broken wires exceeding the count for its construction, diameter reduction, severe corrosion, heat damage, or kinking. Follow rope manufacturer and OSHA guidance.

Anti-two-block device

A safety device that stops hoisting before the hook block contacts the boom tip. It must be tested and functional; a defective device removes the rig from service.

Lockout/tagout

Isolation of energy sources before maintenance or jam clearing. The rig is shut down, controls locked, and the tool landed or blocked before anyone works on it.

Pre-shift inspection

A documented check of fluids, hoses, wire rope, sheaves, brakes, safety devices, and fire extinguisher before each shift. Records are retained as evidence of compliance.

Mast lock verification

Confirmation that mast pins, locks, and safety devices are fully engaged before drilling. Personnel stay clear of the mast fall zone during raising and lowering.

Hydraulic leak search

Never use hands to find a pressurized leak. Use cardboard or paper to detect the pinhole stream, then relieve pressure before opening any fitting.

Weight on bit

The crowd force applied to the drill tool. Too much causes hole deviation, rod bending, and bit damage; too little causes slow penetration and bit polishing.

Kelly alignment

The kelly must align with the rotary table and bushing. Misalignment causes vibration, hole deviation, and rapid wear on the kelly drive and bushings.

Hole cleaning

Removal of cuttings at a rate matching penetration. Slowed returns or rising torque mean reduce penetration rate or increase flush volume before continuing.

Temporary casing

Steel pipe installed to hold unstable ground and control groundwater while drilling. Casing advancement must keep pace with drilling in caving formations.

Tripping loads

Hoisting loads during rod or tool changes must stay within the rig's rated capacity at the working radius, with the rotary stopped and the hole stabilized.

Drilling record

Per-hole documentation of depth, strata, penetration rate, fluid loss, and anomalies. It supports quality control and reveals conditions that affect safety.

Stop-work conditions

Conditions requiring drilling to stop: loss of returns, uncontrolled fluid flow, rig instability, or approach to an indicated utility. Reassess before resuming.

Rated capacity

The load a rig may lift in a specific configuration, from the load chart for that boom length, radius, counterweight, outrigger spread, and quadrant.

Net capacity

Gross chart capacity minus the weight of all lifting attachments, including hook block, slings, shackles, and any below-the-hook device.

Load radius

The horizontal distance from the center of rotation to the center of gravity of the load. Radius is not measured to the hook.

Sling leg tension

For a two-leg bridle, tension per leg equals half the load divided by the cosine of the angle from vertical. Flatter angles sharply increase tension.

Sling angle effect

As the angle from horizontal decreases, tension rises. A 60-degree angle gives about 1.15 times the load per leg; 30 degrees nearly doubles it.

Critical lift

A lift requiring a written plan, often when the load exceeds about 75 percent of chart capacity, passes over personnel, or uses multiple rigs.

Shackle rating

Working load limit based on the pin or bow size and marked on the shackle. Never exceed it, and never side-load a hook beyond the manufacturer's allowance.

Outrigger reaction

The load at each pad, determined by load moment and geometry. Chart capacities assume the specified pad support and level ground.

Operator certification

Crane operators under 29 CFR 1926 Subpart CC must be certified by an accredited body and evaluated. Rig-specific training and employer qualification are separate.

Signal person qualification

A qualified signal person is required whenever the operator cannot see the load or lift path. Hand signals must match the standard set.

Fall protection threshold

Employees on rigs or elevated platforms need protection at 4 feet in general industry and 6 feet in construction, or guardrails or a personal fall arrest system.

Fatality reporting

Fatalities must be reported to OSHA within 8 hours; in-patient hospitalizations, amputations, and eye loss within 24 hours. Preserve the scene and records.

Emergency shutdown

A means to stop the rig from the ground, plus a muster point, first aid and rescue capability, and a spill response plan, drilled before work starts.