Why Enclosed Spaces Are So Dangerous? | Enclosed Space Entry — Transcript

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1. 0:00This vessel is an ERRV or emergency
2. 0:03response and rescue vessel. They
3. 0:05typically work in areas like the North
4. 0:07Sea, standing by offshore installations
5. 0:09like oil rigs just in case they're
6. 0:11needed in an emergency.
7. 0:13A number of years ago, this particular
8. 0:15ERV had an emergency of her own, though.
9. 0:19She was standing by an oil rig in the
10. 0:21North Sea. The weather wasn't too bad,
11. 0:23but it was enough that the ship spent
12. 0:24the night rolling around. It was nothing
13. 0:27that the ship couldn't handle. In fact,
14. 0:28the most inconvenient part was just the
15. 0:30rattling of the anchor chain coming from
16. 0:32the chain locker. This is quite common
17. 0:35on ships, and often crew will just tie
18. 0:37up the chain a bit to stop it from
19. 0:39banging. On this vessel, that's exactly
20. 0:42what they plan to do. Two crewmen went
21. 0:44forwards and went into the forward
22. 0:46store. This is just where they keep
23. 0:48mooring ropes and deck equipment. The
24. 0:50floor of the store, however, forms the
25. 0:52top of the chain locker. Then there are
26. 0:54a couple of manhole covers to get down
27. 0:55into the chain locker itself. Now, these
28. 0:58covers are each secured with a set of
29. 1:00bolts. For any of you that has
30. 1:02experience with these sort of things,
31. 1:04that alone will be the biggest warning
32. 1:06sign of what is about to happen. The
33. 1:09crew removed a total of 18 bolts from
34. 1:11the starboard manhole cover. They could
35. 1:13then see inside and they could see the
36. 1:15chain gently banging around. One crewman
37. 1:18stayed outside with a radio and the
38. 1:20other went in to put lashings onto the
39. 1:22chain to stop the noise. As he went down
40. 1:25the ladder though, he quickly lost
41. 1:27consciousness and collapsed. On seeing
42. 1:30his friend collapse, the crewman outside
43. 1:32the locker called for help on his radio.
44. 1:34He then went in to try and pull his
45. 1:35friend out himself. He too quickly lost
46. 1:38consciousness and also collapsed.
47. 1:41Pretty quickly, the vessel sounded its
48. 1:44general alarm and prepared to rescue
49. 1:46their crewman from the chain locker. The
50. 1:48first man to attempt the rescue couldn't
51. 1:51get down the hatch while wearing
52. 1:52breathing apparatus. So, he swapped that
53. 1:55out for an EED set. EBD means emergency
54. 1:58escape breathing device. It's basically
55. 2:00a hood with an air supply designed to
56. 2:02get somebody out of a contaminated
57. 2:05atmosphere. They can't give sustained
58. 2:07air and they can't cope with heavy
59. 2:09breathing from physical work. As he
60. 2:11reached the bottom of the ladder, for
61. 2:13whatever reason, his EED was no longer
62. 2:16covering his face. He too collapsed and
63. 2:19became the third casualty needing to be
64. 2:21rescued. Shortly after that, the
65. 2:24remaining crew managed to get down into
66. 2:26the locker wearing full breathing
67. 2:28apparatus. At the same time, the oil rig
68. 2:30sent across a three-man extraction team
69. 2:32and a medic to assist. Between them,
70. 2:35they gradually extracted the three
71. 2:37collapsed crew members and brought them
72. 2:39onto deck. The Coast Guard sent medical
73. 2:42assistance and a rescue helicopter. When
74. 2:44they arrived, the helicopter transferred
75. 2:46the three casualties straight to
76. 2:47hospital ashore. But sadly, none of them
77. 2:49actually survived. So, what happened?
78. 2:52Why did three fit and healthy crewmen
79. 2:55perish so quickly in an apparently empty
80. 2:58space? It comes back to those bolts on
81. 3:01the hatch. Remember, I said it should
82. 3:03set alarm bells ringing when you see a
83. 3:06hatch cover secured with bolts. What it
84. 3:08means is the space isn't designed to be
85. 3:10accessed as a matter of routine. is what
86. 3:13we call an enclosed space. Saying that
87. 3:15even a space with a normal door could be
88. 3:18an enclosed space. Enclosed spaces are
89. 3:21just spaces that do not have good
90. 3:24ventilation. They don't have fresh air
91. 3:26inside. Of course, at some point, every
92. 3:29enclosed space was open to the air. Be
93. 3:32it during construction or maintenance or
94. 3:34something like that. You would have
95. 3:35thought that the air in there when it
96. 3:36was sealed up would still be in there
97. 3:38now. But actually the composition of air
98. 3:42inside enclosed spaces is constantly
99. 3:44changing. Think about it. What is inside
100. 3:47the chain locker that we looked at
101. 3:49earlier? You've got the anchor chain
102. 3:51itself and you've got the sides of the
103. 3:53locker. Both of these are made of steel
104. 3:55and steel rusts. Basically, the atoms of
105. 3:59iron contained within the steel react
106. 4:01with oxygen and form iron oxide or rust.
107. 4:05That process naturally removes oxygen
108. 4:07from the space. Over time, enclosed
109. 4:10spaces, particularly ones on ships or in
110. 4:12other metallic structures, have a
111. 4:14naturally depleting oxygen content.
112. 4:16Normal air should contain approximately
113. 4:1878% nitrogen, 21% oxygen, and 1%
114. 4:22everything else. When tested, the air
115. 4:25inside the chain locker we're looking at
116. 4:27actually contained as little as 15%
117. 4:29oxygen. And that was hours later after
118. 4:32all of the rescue activity. But it's not
119. 4:35just rust that can do that. There have
120. 4:37been so many cases of different cargos
121. 4:40doing the same thing. One that comes up
122. 4:42time and again is timber cargo inside a
123. 4:45hold. The timber itself is breathing, so
124. 4:48it uses up oxygen in the air. Now, I'm
125. 4:51not going to go into exactly how you
126. 4:53should enter those spaces in this video.
127. 4:55There are entire courses devoted to that
128. 4:57subject. All I will say is that if
129. 5:00you're ever in doubt as to whether the
130. 5:01space is enclosed, just don't go in. My
131. 5:04hope today is that you've enjoyed
132. 5:06learning about the topic and now
133. 5:07understand a little about the reason why
134. 5:09these spaces are so dangerous. For more
135. 5:12content like this every other Friday, be
136. 5:15sure to subscribe right here on the
137. 5:16channel. Until next time, thank you for
138. 5:18watching and goodbye.