Demolition balling and clamming safety

Only essential workers needed to perform the balling or clamming operations may be in the hazardous area while those operations are taking place; other workers are allowed in that area only when they are necessary for the operation. See 1926.859(a).

• Practical steps: establish and enforce an exclusion zone, post signs, and use barriers or flaggers to keep nonessential personnel out during balling or clamming.

The demolition ball must weigh no more than the lesser of (1) 50% of the crane’s rated load for the boom length and operating angle, or (2) 25% of the nominal breaking strength of the suspension line. See 1926.859(b).

• To comply: obtain the crane’s load chart for the specific boom length and angle to get the rated load, and obtain the manufacturer or supplier data for the line’s nominal breaking strength. Calculate both limits and use the smaller allowable ball weight.
• Document calculations and keep the crane load chart available for inspection.

The maximum allowable demolition ball weight is the lesser of 50% of the crane rated load (4,000 lb) and 25% of the rope breaking strength (7,500 lb), so you must use a ball no heavier than 4,000 lb. See 1926.859(b).

• Action: always perform this calculation for your specific boom length and angle before starting work and retain the math with job records.

OSHA means you must minimize boom extension and the suspended line length consistent with safe operation so the ball is as close as practical to the crane to reduce swing and load. See 1926.859(c).

• Practical application: set up the crane at the closest safe position to the structure, use the shortest boom and reeving that accomplish the task, and avoid unnecessary boom extension or excessively long lines that increase pendulum movement and shock loads.

The ball must be attached with a swivel-type connection to prevent twisting of the loadline and by positive means so the weight cannot accidentally disconnect. See 1926.859(d).

• Use a purpose-built swivel assembly rated for the load and compatible with the line and ball lifting points.
• Ensure all pins, shackles, and bolts are secured with positive locking methods (e.g., safety pins, locknuts, captive clips) and inspected before each lift.

All steel members that will be affected must be cut free before pulling walls or portions of walls over. See 1926.859(e).

• This prevents unexpected structural attachments from resisting or redirecting collapse and reduces the risk of sudden, uncontrolled movement that could injure workers or damage equipment.
• Verify and document that connections (bolts, welds, ties) have been severed before the pull.

All roof cornices and similar ornamental stonework must be removed prior to pulling walls over. See 1926.859(f).

• Removing these overhangs prevents heavy, unsecured items from falling unpredictably during wall collapse.
• Plan removal steps and control the material descent to a safe area before initiating balling or clamming.

A competent person must perform continuing inspections as work progresses to detect hazards from weakened or deteriorated floors, walls, or loosened materials. See 1926.859(g).

• A competent person is someone trained and authorized to identify hazards and take corrective action; they should look for cracks, sagging, undermined supports, loose masonry, displaced bracing, and other signs of instability.
• If hazards are found, no employee may work where they exist until corrected by shoring, bracing, or other effective means.

Acceptable corrective actions include shoring, bracing, or other effective means to eliminate the hazard before employees can work in the affected area. See 1926.859(g).

• Choose the corrective method based on condition and loads—examples are installing temporary shores, diagonal bracing, buttresses, or removing the unsafe material.
• Document corrective measures and re-inspect before allowing work to resume.

Establish an exclusion zone that keeps all nonessential workers out during balling operations and ensure a competent person monitors the area for hazards throughout demolition. See 1926.859(a) and 1926.859(g).

• Practical measures: use physical barriers, flaggers, chain-link or caution tape, signage, and a dedicated watch person; restrict access with site-specific procedures.
• The competent person should patrol and verify the exclusion zone remains intact and that no workers enter inadvertently.

While 1926.859(d) specifically requires a swivel-type connection to prevent twisting and positive attachment so the ball cannot disconnect, using tag lines or other controls to limit swing and rotation is a recommended safe work practice although not explicitly mandated in this paragraph. See 1926.859(d).

• Use tag lines, guide ropes, or positioning devices to control the ball’s movement and prevent it from striking unintended areas or people.
• Ensure tag lines are used by trained personnel and kept clear of pinch points and crane operations.

Boom angle and working radius affect the crane’s rated load at that configuration, so you must use the rated load for your specific boom length and angle to calculate the 50% limit and keep the boom and loadline as short as possible to reduce radius and increase capacity. See 1926.859(b) and 1926.859(c).

• Always consult the crane load chart for the actual boom angle and radius before selecting the ball.
• Position the crane to minimize radius and avoid operating at maximum outreach when heavy ball weights are used.

Removing steel attachments and ornamental stonework prevents unpredictable load paths and falling debris that could cause uncontrolled collapse or strikes; failing to do so can create hazards to workers and equipment. See 1926.859(e) and 1926.859(f).

• Examples of risks: attached steel members can hold parts of a wall in place until sudden failure causes large sections to fall, and cornices can detach and fall unpredictably causing struck-by injuries.
• Mitigation: cut or remove attachments and ornamental elements under controlled conditions before initiating the pull.

You should document the competent person’s continuing inspections and, if PPE is required, complete and keep a written hazard assessment and PPE certification showing what hazards were identified and the PPE selected. See 1926.859(g) and OSHA’s PPE hazard assessment guidance in the letter of interpretation at https://www.osha.gov/laws-regs/standardinterpretations/2024-03-28.

• The PPE LOI explains that when PPE is required, employers must assess hazards and create a written certification of the workplace evaluation (see https://www.osha.gov/laws-regs/standardinterpretations/2024-03-28).
• Keep inspection records, correction actions (shoring, bracing), and PPE assessment forms with the job file for accountability and refresher training.

Only workers who are necessary for performance of the operations (including staging or cleanup that is necessary to the operation) may be permitted in the area at any time; nonessential personnel must remain out. See 1926.859(a).

• Ensure supervision identifies who is "necessary" for tasks and restricts access accordingly.
• Use a competent person to assess if staging or cleanup tasks can be done safely without exposing people to collapse hazards.

Before starting operations, inspect the swivel, shackles, hooks, and all attachment hardware for proper rating, deformation, cracks, corrosion, secure locking devices, and correct installation so the weight cannot accidentally disconnect. See 1926.859(d).

• Verify markings that show rated capacities, verify compatibility of components, and ensure pins are secured with positive locking means.
• Remove any defective hardware from service and replace with rated components.

You may use a ball up to 25% of the line’s nominal breaking strength only if that value is less restrictive than 50% of the crane’s rated load for your boom configuration; you must use the lesser value of the two limits. See 1926.859(b).

• Do not choose the higher value—always calculate both limits and select the smaller allowable ball weight.
• Ensure rope breaking strength is from manufacturer specs and match rope type and condition on the job.

Site layout should position the crane as close as safely possible to the structure, clear obstacles that force long outreach, and select ground that supports the crane so shorter boom and line configurations can be used. See 1926.859(c) and general crane setup practices in 1926.

• Consider access roads, ground preparation, and materials staging to reduce required radius and minimize the need for counterweights or long booms.
• Re-evaluate layout as demolition progresses and hazards change so the crane setup remains optimal.

Inspections must be continuing as the work progresses, meaning the competent person should inspect regularly and whenever conditions change or there is reason to suspect new hazards. See 1926.859(g).

• In practice: inspect at the start of each shift, after any significant demolition event, after severe weather, and whenever changes (e.g., cuts, pulls) could affect stability.
• Document inspection times, observations, and corrective actions.

Workers necessary for the operation must be trained in the hazards of balling/clamming, safe work procedures, exclusion zone rules, and the signs of structural instability; a competent person should also be trained to recognize hazards and direct corrective action. See 1926.859(a) and 1926.859(g).

• Training topics: proper rigging, use and inspection of swivel connections, exclusion zone enforcement, recognition of weakened floors/walls, emergency procedures, and use of required PPE.
• Keep records of training and tailor it to site-specific hazards.

No — the ball must be attached by positive, rated means so the weight cannot become accidentally disconnected; knots or non-rated connectors are not acceptable. See 1926.859(d).

• Use rated swivel assemblies, shackles, and hardware sized and marked for the load.
• Replace temporary or jury-rigged connections with certified lifting gear before beginning operations.

The demolition plan should specifically sequence cutting/removal of steel members and ornamental stonework before any pulling activities, and document methods, personnel, controls, and inspections to verify they are completed safely. See 1926.859(e) and 1926.859(f).

• Include assigned responsibilities, verification steps, checklists, and a competent person sign-off before initiating ball pulls.
• Coordinate crane movements so removal crews are clear and protected during the sequence.