First, describe the work and worksite
A two-person crew will make a released horizontal core through an existing ground-floor concrete wall using an anchored electric drill stand and wet drilling system. Both faces of the wall can be controlled. This fictional learning example records planned controls; it supplies no actual inspections or work authorization.
- A structural and service investigation must release the hole, depth, anchorage and core removal method.
- No post tensioned or prestressed concrete, overhead drilling, unknown coating, occupied receiving face or elevated access is included.
- This replaces neither a structural alteration design nor an electrical isolation procedure.
Questions before work
- What evidence releases the hole and stand anchors?
- How will the core be restrained and both wall faces protected?
- Which wet drilling, electrical and silica-control arrangements fit this rig?
Build the analysis one step at a time
What will the worker do? How could someone be harmed? What prevents or reduces that exposure? Who checks the control, and when?
1. Release the hole and receiving face
Hazard: The bit can strike a service or damage a structural element; the core can emerge into another work area.
Control: Foreperson obtains the structural and service release, marks the permitted location and depth, and controls both faces. Unresolved reinforcement or services keep drilling on hold.
Verification: Operator compares the markings with the current release and confirms access to the receiving face.
Why this belongs in the analysis: A surface mark cannot establish hidden conditions.
2. Arrange water and electrical supply
Hazard: Water can contact electrical equipment, spread slurry or obstruct an exit.
Control: Use a supply and protective electrical arrangement suitable for the wet equipment and site requirements. Route hoses and cords away from access and contain discharge before drilling.
Verification: Designated competent person checks the supply arrangement; crew checks the collection route and exit.
Why this belongs in the analysis: The wet method creates an electrical and housekeeping interface.
3. Install and inspect the drill stand
Hazard: An inadequately secured stand or incompatible bit can move violently or eject parts.
Control: Install the stand using the actual anchorage method and manufacturer criteria for the released substrate. Inspect bit, drive, guard and controls. Do not substitute a vacuum mount for the planned anchor arrangement.
Verification: Operator verifies stand installation and equipment checks against the unit’s instructions before loading the feed.
Why this belongs in the analysis: Stand attachment must resist the actual drilling forces.
4. Drill within the released limits
Hazard: Contact with rotating parts, unexpected binding, noise and silica exposure can injure the crew.
Control: Operate from the designated position with guards intact and the approved wet dust-control method functioning. Keep hands clear, maintain the two-face boundary and stop for binding, lost water or unexpected material.
Verification: Operator checks water delivery before feed and monitors the rig; silica competent person checks the employer’s applicable control plan.
Why this belongs in the analysis: The tool and wet-control method must remain matched throughout the cut.
5. Restrain and remove the core
Hazard: A released concrete cylinder can fall, crush hands or overload the removal method.
Control: Use the planned core restraint and removal equipment before breakthrough. Stop the drill and secure energy before handling the core; keep people out of the receiving and drop area.
Verification: Foreperson confirms restraint and receiving-face clearance before final breakthrough.
Why this belongs in the analysis: Breakthrough is a separate task with a falling-object exposure.
6. Protect the opening and clean up
Hazard: An open penetration, wet slurry or dried dust can expose the next crew.
Control: Secure the required opening protection, collect slurry while wet and follow site disposal arrangements. Use an appropriate wet or HEPA cleanup method and hand over the penetration status.
Verification: Foreperson confirms protection and cleanup at both faces before releasing the area.
Why this belongs in the analysis: The receiving face needs the same closeout attention as the operator’s side.
What does a useful control look like?
| Needs improvement | More useful for this scenario |
|---|---|
| Be careful around the equipment. | Install the stand using the actual anchorage method and manufacturer criteria for the released substrate. Inspect bit, drive, guard and controls. Do not substitute a vacuum mount for the planned anchor arrangement. |
| Check the area before starting. | Foreperson obtains the structural and service release, marks the permitted location and depth, and controls both faces. Unresolved reinforcement or services keep drilling on hold. |
Decisions that change the analysis
Which silica pathway applies to this wet core rig?
Table 1 row vi addresses rig-mounted core saws and drills with integrated water at the cutting surface and proper operation and maintenance. With that method fully and properly implemented, the row does not require a respirator for the silica task. If it is not implemented, use the applicable alternative exposure-control pathway. Other hazards can still require respiratory protection.
What must be recorded before this example is used on a job?
Replace the scenario with the actual work, identify additional hazards with the crew, and record the applicable instructions, responsible people, inspection findings, unresolved actions and required authorization. A planned verification is not an inspection result.
Agree when the crew will pause
- Service or structural release is unclear or unexpected material is encountered.
- Stand moves, water fails, electrical protection trips or the bit binds.
- Receiving-face protection or core restraint cannot be maintained.
After a pause, correct the condition, reassess the work, and obtain required authorization before restarting. Keep unresolved actions visible.
Download the worked example and free template
No account or paid membership required. The worked example contains planned controls. The blank template is for your own work; neither includes fabricated inspection results, signatures or approval.
Your editable working copy
Build and download your draft
Start blank or load the learning example. Replace its assumptions with your actual conditions and involve the people doing the work. Your entries stay in this browser tab; download a copy before leaving or refreshing.
1. Describe your work and site
2. Work through each task
Describe an observable step, how someone could be harmed, and the control that acts on that hazard. Identify who checks it and what evidence is needed.
3. Record changes, checks, and open actions
Walk the work area, review with the crew, and resolve missing controls. Follow the required approval process. This tool does not judge completeness, verify signatures or authorize work.
Open the downloaded file in a browser, then use Print → Save as PDF for a printable copy.
Training needs to confirm
- Rig setup, safe feed, isolation and core handling for the actual unit.
- Silica-control instruction under the employer’s applicable exposure plan.
Confirm applicable qualifications, task instruction and actual training evidence for the people assigned. Related toolbox talks support crew discussion; they do not establish competence.
Common questions
Can this be used as a JSA?
Use the Task | Hazard | Control structure if it meets the employer’s format. Adapt the boundaries, controls, verification and records to the actual job.
Does this provide a completed USACE AHA?
No. Use the project’s required AHA process, risk method, supporting fields and acceptance requirements. The existing formwork AHA explains the additional structure.
Are these resources part of a paid course?
This walkthrough, browser draft builder and downloads are free public resources, separate from Academy course enrollment.
References and source note
- OSHA 1926.300 Hand and power tools
- OSHA 1926.1153 Respirable crystalline silica
- OSHA 1926.21 Safety training and education
Original worked example developed for the stated scenario. Primary references support the planning framework; the actual equipment manual, product instructions and project design must supply applicable operating and acceptance criteria. Use actual equipment instructions and site requirements alongside these references. Reference review: October 9, 2026.