1. Crushed by a falling wale during dismantlement (Serious Accidents in Construction) Construction 2009.05 The copyright to this material belongs to the Korea Occupational Safety and Health Agency. Unauthorized use and distribution are prohibited. If an individual uses this for non-commercial purposes, the Korea Occupational Safety and Health Agency must be cited as the source. A corporation using this material must obtain permission from the Korea Occupational Safety and Health Agency first. Using this material without prior permission will be considered copyright infringement, and legal action may be taken. 건설분야 - 교육자료 미디어개발 2009-85-463

2. Table of Contents I. Fatality Overview II. Site Overview III. Fatality Description IV. Fatality Cause V. Precautions

3. Think it over! Find out the Hazard Points in the figure below.

4. Date & Time: 14:15, February 2, 2007 (Friday) Place: new roadbed construction site in the 2 nd Section of double tack subway Victim: steel-frame worker (male/40) and one other worker of subcontractor for structure building The victim was about to change five stage wale (H: 250 × 250 × 9 × 14) on a temporary retaining wall installed on a beam hanger ( Ø 22mm, deformed bar) with another wale with different standard. While a co-worker went for a help to the backhoe operator, the victim was cutting welded filling area between already installed side pile and wale, the center of gravity of wale with 14 piece brackets (H: 298 × 299 × 9 × 14) fell down upon the victim. 119 rescue services took him to the hospital. He died during medical treatment. Crushed by a falling wale during dismantlement 1. Fatality Overview Site Overview New roadbed construction site in the 2 nd Section of double tack subway (total 940m long, 1 tunnel, 1 station) - Excavation for a station and installation of temporary retaining wall were under way (overall process rate was 13.8%)

5. At about 06:30, 4 workers including the victim (male/40, steel-frame worker) of a subcontractor for tunnel and structure building went to the station construction site and got ready for the work. At about 07:00, they did morning exercises on plate-type temporary paving of the station and received safety education and a work order (Type-C septic tank in the station, installation of 5 stage wale and struts near sewage disposal tank, etc). At about 07:20, the victim prepared tools and went to the workplace with a co-worker. He placed 5 stage wale (H: 250×250×9×14, L: 10.5m, W: 72.4kgf/m) on a beam hanger ( Ø 22mm, deformed bar) that was installed in the previous day using a backhoe and finished fixing welding at about 10:00. After that, a supervisor ordered him to change the wale because the standard of the five stage wale (H: 298 × 299 × 9 × 14) was changed. Crushed by a falling wale during dismantlement 3. Fatality Description (1)

6. After lunch at about 13:00, the victim completed welding of temporary retaining wall with his co-worker and moved to the accident spot. At about 14:15, while a co-worker was gone for a help to the backhoe operator (approx. 30m away) to dismantle the already installed wale (H- 250×250×9×14), the victim was cutting the filling between already installed side pile and wale. - At this time, the center of gravity of wale with 14 piece brackets (total weight: 609kg) (H: 298×299×9×14, L: 0.5m, W: 87kgf/m) moved forward and the wale fell upon the victim. - 119 rescue services took him to the hospital. He died during medical treatment at about 12:36 on the next day. Crushed by a falling wale during dismantlement 3. Fatality Description (2)

7. Crushed by a falling wale during dismantlement

8. Crushed by a falling wale during dismantlement

9. Crushed by a falling wale during dismantlement

10. Crushed by a falling wale during dismantlement

11. Crushed by a falling wale during dismantlement

12. Crushed by a falling wale during dismantlement

13. Improper working process - To handle heavy objects such as wales (dismantlement of temporary retaining wall), you should handle them according to work plans considering heavy object ’ s type and shape, handling method and order, workplace size and topography. Furthermore, you should dismantle wales using lifting equipment or wire ropes. However, these rules were not observed. No assignment of supervisor - To handle heavy objects such as wales (dismantlement of temporary retaining wall), a supervisor should be assigned to decide working order and process. However, this rule was not observed. Crushed by a falling wale during dismantlement 4. Fatality Cause

14. Improving working process - To handle heavy objects such as wales (dismantlement of temporary retaining wall), you should handle them according to handling method and order in a work plan. To dismantle a wale, you must hang the wale using lifting equipment or wire ropes to cut filling, connecting part in order to prevent wale fall. Assignment of a supervisor - To handle heavy objects such as wales (dismantlement of temporary retaining wall), a supervisor should be assigned to decide wale dismantling order and working process and to direct the work. Crushed by a falling wale during dismantlement 5. Precautions

15. Thank You.