Question 1

Before using a portable multi-gas detector to test the atmosphere in an enclosed space, the crew member carries out a "bump test" using a small cylinder of calibration ("span") gas. What is the purpose of this check?

Accepted Answer

To verify, before each use, that the detector's sensors respond correctly and promptly to a known concentration of test gas and that the alarms activate at the correct set points — confirming the instrument is functioning correctly and giving the user confidence that a "safe" reading in the enclosed space genuinely reflects a safe atmosphere, rather than a faulty or unresponsive sensor giving a false safe reading A multi-gas detector typically measures oxygen, flammable gas (LEL/LFL), and toxic gases such as hydrogen sulphide and carbon monoxide — all critical readings before entering an enclosed space. However, sensors can drift, become contaminated, or fail over time, and a detector with a failed sensor may continue to display a reading (sometimes still showing "normal" air values) that gives a false sense of security. A bump test involves briefly exposing the detector to a known concentration of calibration/span gas (often from a small canister) and confirming that each sensor responds appropriately and that the audible/visual alarms trigger at their set thresholds. This is distinct from full calibration (which adjusts the instrument's readings to match a reference standard and is typically done periodically by a competent person or returned to the manufacturer/agent) — a bump test is a quick functional check that should be carried out before each use, or at least daily if the instrument is in frequent use, as part of the enclosed space entry permit procedure. Relying on a detector that has not been bump-tested could result in a fatal misjudgement of the atmosphere in an enclosed space.

Question 2

You're asked to test a deck crane grab after electrical repairs nearby. As the grab is hoisted, what should have happened first?

Accepted Answer

The area within the grab's swing radius should be cleared of personnel before the lift On the bulk carrier Fairfield Eagle, a crew member working nearby was struck and fatally injured when a grab being test-lifted after repairs swung unexpectedly. The investigation found the area should have been cleared and barriered before the test lift began.

Question 3

A toolbox talk held before a lifting operation should explicitly cover which of the following?

Accepted Answer

Who must remain clear of the exclusion zone while the lift takes place A toolbox talk exists to make sure everyone present understands the danger zones, the abort signal, and — critically — who must not be in the area while the lift happens. The RMIMA investigation into the Fairfield Eagle fatality found the toolbox talk had not made this clear.