COSWP brief — Muster Mate

CHAPTER 15

Entering Enclosed Spaces

Chapter 15 covers the hazards, procedures, equipment and responsibilities for safely entering any space on board with limited ventilation or access.

What's in this chapter

Scope and purpose of enclosed space entry rules

Chapter 15 covers any space not designed for continuous occupancy that has limited access or inadequate ventilation — tanks, void spaces, cofferdams, chain lockers, pump rooms and more. The list is long and not exhaustive. The chapter explains why these spaces are hazardous, who is responsible for authorising entry, what a ship's register of enclosed spaces should contain, and what training crew need. It also covers atmosphere testing, permits to work, breathing apparatus, and emergency rescue arrangements.

The main practices

How the chapter says to approach every entry

Every entry follows a structured sequence: assess, prepare, test, authorise, enter with controls in place, and secure on completion.

Build and maintain a register of enclosed spaces on board.
Test the atmosphere from outside before anyone enters — oxygen, flammable gas, then toxic gas.
Issue a permit to work that names the space, the hazards and the controls in place.
Post a trained standby person at the entrance, in constant contact with the team inside.
Keep rescue and resuscitation equipment ready, and drill enclosed-space rescue regularly.