| Case Name |
Fire in a tunnel caused by sparks from gas cutting in demolition of a jumbo drill truck. |
| Pictograph |
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| Date |
March 20, 1979 |
| Place |
Tanigawa, Minakami Town, Tone District, Gunma Prefecture. |
| Location |
In the tunnel nearly 5375m away from the entrance of the inclined tunnel. |
| Overview |
When the work of disassembling a steel drill jumbo ( 21 booms ) used in the tunnel for full face excavation was done with the boring of the tunnel, oil and the like adhered in a deck of the drill jumbo was ignited by sparks from the gas cutting. And it resulted in fire. |
| Incident |
While doing the disassembling work, combustibles soaked by oil and the like adhered at the middle deck of the drill jumbo were ignited by sparks from gas cutting at the upper stage deck, and the fire started, and the thick smoke flowed in the direction of the inclined tunnel leeward. Therefore, 14 persons of 46 pitmen who ran in the direction of the inclined tunnel leeward didn't escape, were suffocated by smoke, and died because of the smoke.
And, after the fire started, 2 people who wore respirators ( 8 liter ) and escaped from the inclined tunnel to tunnel interior consumed all the portable air and died. However, all the members of the 8 workers who escaped windward were saved. |
| Sequence |
The tunnel where the fire started was a 5350m tunnel of the second section from starting point side in the tunnel which was 22235m long and divided into 6 sections, and it had 518m inclined tunnel on the border of sections in the starting point side.
Still, the place where the fire broke out was 70m away from the border of sections in the end side, and 14950m away from the entrance of the end side ( windward ) and 7285m away from the entrance of the start side ( lee side ) , and the tunnel had already been bored.
On that day, 54 persons on night duty worked in the tunnel, and 29 persons who worked comparatively close to the inclined tunnel all took refuge. The work of disassembling the drill jumbo ( 11 persons ) was carried out near the border of sections, and preparation of the lining concrete ( 14 persons ) was carried out near 250m away from the border in the start side.
Of the 11 persons who did the work of disassembling , 8 persons who took refuge windward were saved, and 3 persons who escaped leeward had died. All the members of the 14 persons who did the preparation of
concrete escaped leeward. 3 persons were saved and 11 persons died. The 14 people who died had fallen within 1000m
of the lee side of the place where the fire broke out. |
| Cause |
* Sawdust soaked by oil adhered at middle stage deck of the drill jumbo was ignited by sparks from gas cutting by the disassembling work at the upper stage deck.
* Discovery of the fire was late.
* Fire extinguishing agent of fire extinguisher did not jet out.
* The early fire extinguishing failed, and the refuge was delayed.
* Report to the leeward workplace was delayed.
* Lagging was burned by the strong wind from the end point with the boring, and smoke and toxic gas filled the tunnel interior at once. |
| Response |
* Shortly after the accident, the countermeasure headquarters was established and the rescue system was systematized by the local fire station and the company's own special rescue party, but smoke that gushed out from the entrance of the inclined shaft was so severe that they had to continue to wait in the entrance of the tunnel. Afterwards, waiting for the smoke to be dissipate, the rescue party entered the tunnel, and in 4 days, all the members who died had been accommodated. |
| Countermeasures |
* Extraction of operating oil and disconnection of the hydraulic hose are carried out before the work with a fire ( disposing of nearby combustibles ).
* Instrument and equipment for extinguishing fires are prepared before the work with a fire( arrangement of fire extinguisher ).
* By stationing the fire prevention staff, the work is watched. ( arrangement of the monitoring person ) |
| Knowledge Comment |
* Work is carried out after the operational procedure is decided, and it is communicated effectively to all of the party.
* Combustibles around the place of the work are removed or isolated by incombustibles, when the work with a fire is carried.
* By establishing partition walls and the like, the wind velocity of the air current in the tunnel is controlled .
* Alarm and call equipment are installed.
* Refuge tools ( respiratory mask for refuge, light, etc. ) are installed.
* The accumulator-run fire extinguisher is adopted ( the pressurizing-run fire extinguisher is sensitive to moisture ). |
| Background |
* All construction of sections had been bored, and the considerably strong wind in the tunnel from the end point to the starting point blew at speeds of 5m per second. |
| Incidental Discussion |
Many people have sacrificed their lives in the tunnel fire. The closest attention must be paid, when the fire is used.
The underestimation is taboo. |
| Scenario |
| Primary Scenario
|
Organizational Problems, Poor Management, Carelessness, Insufficient Precaution, Poor Response to Change in Environment, Change in Environment, Insufficient Analysis or Research, Insufficient Environment Study, Non-Regular Action, Inaction, Incorrect Reaction, Poor Communication, Non-Regular Action, Emergency Action, Bad Event, Chemical Phenomenon, Failure, Large-Scale Damage, Bodily Harm, Death, Loss to Organization, Economic Loss
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| Sources |
Japan Construction Safety and Health Association, newspaper article.
|
| Number of Deaths |
16 |
| Number of Injuries |
15 |
| Field |
Civil Engineering
|
| Author |
KITAJIMA, Munekazu (TEKKEN CORPORATION)
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