QUESTION 10.3.8

Electric-welding equipment and return-current safety

Oil, Chemical, LPG, LNGEngine Room, Interview - Engine Rating

What is being checked

The inspector is checking whether electric welding is conducted with sound equipment, correct return-current arrangements, effective isolation and precautions that prevent shock, fire and stray-current damage.

Ready onboard

0/6 complete

EQUIPMENTPower source, holder, leads, connectors, insulation, casing and controls are free from damage and unsuitable repairs.RETURN LEADA dedicated return lead is connected close to the work; hull structure, bearings and pipelines are not used as an uncontrolled return path.ISOLATIONThe machine is de-energised when unattended and supply protection and emergency isolation are accessible.ENVIRONMENTDry working conditions, insulation, ventilation, PPE and protection from confined or conductive-space hazards are provided.POSTED RULESClear vessel precautions and shock-response instructions are displayed and understood.PERMITHot-work authorisation, fire watch, gas testing and post-work inspection remain fully applied.

Practice questions

Answer aloud, then open the preparation point.

1Where must the return clamp be connected?

Directly to clean metal on the workpiece or approved point close to the weld so current does not pass through machinery or bearings.

2Why is the hull not an acceptable default return?

Uncontrolled current can arc across bearings, damage equipment and create ignition paths remote from the work.

3What extra controls apply in a damp or confined location?

Use the approved low-risk equipment and insulation, ventilation, rescue, gas testing and permit controls; stop if safe conditions cannot be established.

4What defects require withdrawal from service?

Exposed conductors, damaged insulation, overheating, loose connectors, defective holder, casing damage or unreliable isolation.

5Does a welding-machine inspection replace the hot-work permit?

No. Equipment condition and worksite fire or atmosphere control are separate requirements.

Where an observation may arise

STRAY CURRENT

The return path can pass through machinery, bearings, pipes or structure.

DAMAGED LEAD

Conductors or connectors are exposed, overheated or repaired improperly.

WET WORK

Shock protection is inadequate for damp or conductive conditions.

LIVE UNATTENDED

The unit remains energised without control.

RULES UNKNOWN

Users cannot explain posted precautions or emergency isolation.

Master's practical note

Follow the return lead physically. Many welding arrangements appear serviceable until the clamp location reveals a current path through propulsion or other critical machinery.

Equipment boundary and references

Equipment boundary: Welding in tanks, confined spaces, cargo areas or on fuel boundaries requires additional restrictions and permits. Follow the equipment maker and vessel hot-work procedure.

References

OCIMF SIRE 2.0 Question Library Part 2, Version 1.0, Question 10.3.8
SOLAS Chapter II-2
ISM Code sections 7 and 10
Company hot-work procedure
IEC 60974 series

Last reviewed: 2026-09-10