Confined space entry SOP for ship repair yards

What the confined space entry SOP for ship repair yards process is

A ballast tank or cofferdam on a vessel in for repair is not a room that happens to be enclosed. It can be oxygen-deficient from steel corrosion, hold flammable vapor from a fuel space next door, or have been gas-freed weeks ago and slowly re-contaminated since. The reason a confined space SOP is drawn as a sequence of gates rather than a checklist is that every one of those hazards is invisible at the hatch: nothing about how the space looks tells a technician whether the atmosphere inside is safe, and the schedule pressure of a dry dock is exactly the condition under which someone opens a hatch and decides to "just take a quick look." The risk assessment decision has to sit before any preparation work starts, and a hard reject has to be a real, terminal outcome, not a soft warning that gets overridden because the job is behind schedule.

The lane order also encodes a sequencing rule that matters more than it looks: isolation and ventilation happen before atmosphere testing, not after. Locking out the electrical, mechanical and piping systems that feed the space, then purging it, is what makes the atmosphere reading meaningful in the first place, a test run against a space that hasn't been isolated yet is measuring conditions that are about to change. The same logic applies to the standby and rescue gate at the entry lane: a permit says the space and atmosphere were assessed as workable, it does not say a standby person is physically in position with rescue equipment staged. Most confined space fatalities on record involve a rescuer going in after a downed worker with no plan, which is why this template keeps standby readiness as its own decision, separate from the permit, rather than folding it into a single sign-off.

Every row in this chart carries a named person and a workload figure in hours, which is what lets the workload BI panel do something a paper permit can't: total a person's booked time across the whole entry and flag when the same name is carrying two roles on one shift. On a small repair crew the gas-free engineer often is the closest qualified person to double as standby, and that's a legitimate staffing choice, but it should be a visible, deliberate one on the schedule, not something discovered when two things need that person at once.

What this flowchart covers

In this template

• The "Identification" lane opens with the space itself flagged as confined, "Confined space work identified (tank, void, cofferdam)", followed by a formal risk assessment. The "Risk assessment finds the space entry-safe with controls?" decision is a real gate: a hard no ends at "Entry prohibited, alternative method required" rather than a warning that can be talked past, so a tank the assessment can't clear never reaches the crew.
• The "Preparation" lane runs "Isolate, lock out and tag electrical, mechanical and piping systems" and "Ventilate space and stage rescue equipment" before any atmosphere reading is taken, so the test that follows measures the space after its hazards have been shut down and purged, not before.
• In "Testing and permit", "Test atmosphere for oxygen, flammable gas and toxins" feeds the "Atmosphere safe for entry without breathing apparatus?" decision. A marginal reading doesn't stall the job, it branches to "Set up continuous atmosphere monitoring for the entry", and either path converges on "Issue confined space entry permit", so the permit always follows a documented atmosphere check, never precedes it.
• The Entry lane gates on people, not paperwork: "Assign standby person and confirm rescue plan" feeds "Standby, rescue equipment and communications all in place?", and an unready crew is routed to "Delay entry until standby and rescue readiness are confirmed" instead of being allowed to start against an already-issued permit.
• Once inside, "Personnel enter and carry out the work" and "Periodic atmosphere re-check and communication with standby" repeat on a loop, and "Work complete and all personnel accounted for on exit?" is the one decision standing between the crew and "Continue work, repeat periodic checks", headcount is verified before the space is ever treated as clear.
• Every step carries a People assignment and a Workload figure in hours, and this is where the numbers get interesting: the "Gas-Free Engineer" is booked across atmosphere testing in "Testing and permit" and standby duty in "Standby / Rescue" on the same shift, exactly the kind of stacked workload the BI panel exists to surface before it becomes a scheduling conflict. The chart closes with "De-isolate systems, remove tags and close the entry permit" and "Confined space entry closed out", nothing gets de-isolated before the work itself is confirmed done.

When to use this template

• A vessel arrives for repair with ballast tanks, void spaces or a cofferdam that need work, and you need a documented, repeatable permit process before crews go in rather than a verbal briefing at the hatch.
• Your yard runs confined space entries on paper permits or a single spreadsheet tab, and a class surveyor or client audit has asked to see the actual decision path behind the sign-off, not just the final signature.
• You want to track who is doing the gas testing, who is standing by, and how many hours each role is booked for on a given entry, instead of finding out about a scheduling clash after the fact.
• A near-miss or stop-work event turned up a step that got skipped, ventilation cut short, a permit issued before testing, standby left unconfirmed, and you need a diagram that makes that step impossible to route around silently.
• You're onboarding a new gas-free engineer or HSE officer and need one page that shows the full sequence from identification to permit closeout, rather than a policy document they'd have to reverse-engineer into steps.

How it works

1. Match the lanes to your own crew roles

   This chart uses Technician, HSE / Safety, Gas-Free Engineer and Standby / Rescue because that's how a ship-repair yard typically staffs an entry. If your site combines the gas-free and standby function into one qualified person, collapse the lanes, but keep the atmosphere and readiness decisions as two separate gates even when the same person owns both.

2. Keep the reject branch a dead end, not a detour

   Entry prohibited, alternative method required is deliberately terminal. If your process actually re-routes a rejected assessment to an alternative method, remote inspection, robotic entry, add that as its own lane rather than looping the reject branch back into the risk assessment step, a loop reads as "keep reassessing until it says yes."

3. Put real numbers on the atmosphere and readiness decisions

   The template leaves the oxygen, LEL and toxin thresholds, and the definition of a ready standby crew, implicit in the box labels. Record your yard's actual limits and required equipment in each row's comment field so the decision reflects a number, not a judgment call that varies with whoever is on shift.

4. Assign People and Workload before relying on the BI panel

   The workload BI panel only surfaces a conflict if every row has a person and an hour figure attached. Fill in both columns with named roles, not "TBD", especially on the atmosphere-testing and standby rows, where the same person is often double-booked without anyone noticing until the workload total makes it visible.

5. Turn on approval before the first revision

   Confined space procedures get amended after incidents, equipment changes and audits. Enable the approval workflow so a revised sequence carries a reviewer's name and a timestamp, and past entries stay attributed to the exact version of the SOP that was in force when they happened.

Frequently asked questions

What counts as a confined space on a ship-repair job?

Any tank, void, cofferdam, double-bottom, or other space with restricted entry and exit and the potential for a hazardous or oxygen-deficient atmosphere. On a vessel in for repair that includes ballast tanks, fuel tanks that have been gas-freed, voids between hulls, and cofferdams isolating cargo or fuel spaces, anywhere the atmosphere can't be assumed safe just because the hatch is open.

Why does the atmosphere decision have a marginal branch instead of just pass or fail?

A borderline reading doesn't mean the space is unsafe, but it does mean one spot check isn't enough. The template routes a marginal result to continuous monitoring for the duration of the entry, rather than forcing the tester to round a borderline number up to safe or down to reject.

Why is the standby and rescue check a separate decision from issuing the permit?

A permit documents that the space and atmosphere have been assessed as workable, it says nothing about whether a standby person is actually in position with a rescue plan confirmed at that moment. Splitting them into two gates means a valid permit can still hold entry back if the people side isn't ready, which is the gap most confined space fatalities trace back to.

How do the People and Workload columns change what this SOP shows?

Beyond recording who owns each step, the workload figure in hours lets the BI panel total a person's booked time across the whole entry. On this chart that surfaces the Gas-Free Engineer's testing and monitoring hours overlapping with the Standby / Rescue lane, a conflict a static procedure document would never show.

Can this template be adapted for confined spaces outside a shipyard?

Yes. The lane structure and decision points, risk assessment, isolation, atmosphere testing, standby readiness and closeout, are the same for a tank farm, a manufacturing plant or a utility vault. Rename the lanes and swap the isolation and rescue-equipment steps for whatever your site actually uses.

Where this process fits

In most operations this process follows Shipyard subcontractor onboarding SOP: induction to checkout.

Comes before

• Shipyard subcontractor onboarding SOP: induction to checkout — A shipyard subcontractor onboarding SOP for ship repair yards: document and insurance verification, a pass/fail safety induction, access and PPE issue, a hot work or confined space permit decision, supervised work and checkout.

Related processes

• Confined space entry process flowchart (permit-required entry)

  Confined space entry flowchart template: the avoid-entry test, isolation and lock-off, ventilation, gas testing, rescue cover, permit issue, attendant and monitoring, evacuation, headcount and permit cancellation.

  Alternative

• Hot work permit SOP: gas test, fire watch, and closure

  A hot work permit SOP for ship repair: gas-test the atmosphere, assign a fire watch, get dock master and HSE sign-off, then hold a mandatory post-work watch before the permit closes.

  Same family

• Permit to work process flowchart (issue, suspend, hand back)

  Permit to work process flowchart template: screening, risk assessment, permit type, isolation and proving, second signature, issue and display, suspension, shift handover, hand-back and cancellation.

  Same family

• Energy isolation process flowchart (multi-energy process plant)

  Energy isolation process flowchart template: isolation boundary and energy sources, isolation standard, scheme approval, lock and tag, purge, zero-energy proving, isolation certificate and reinstatement.

  Same family

• Toolbox talk process flowchart (daily pre-task safety briefing)

  Toolbox talk flowchart template: topic from the talk plan or a recent incident, controls from the risk assessment, the talk delivered at the workface, issues fixed, logged or stopped, attendance recorded.

  Same family

• Hot work permit process flowchart (welding, cutting and grinding)

  Hot work permit process flowchart template: cold-method challenge, area fire risk assessment, combustibles cleared, fire watch appointed, gas test, time-limited permit, suspension on alarm, post-work watch and closure.

  Same family

Part of

• Marine, offshore & industrial services
• Permit to work
• Ship repair

QueryChart features for this process

• Version control
• Audit trail