Large naphtha storage tank fire at Tomakomai, Japan (part 2) National Research Institute of Fire and Disaster, Japan Hiroshi Koseki

Two fires occurred after the eathquake Crude oil tank Ｓｅｐｔｅｍｂｅｒ 26, 2003, just after the earthquake Naphtha tank fire September ２８, １０ : ４９ AM Koseki was asked to help fire-fighting against the second fire, who was in Tokyo. About 5 hours after fire, he was there.

Summary of Naphtha tank No tank, floating roof, single roof Storage volume ３２，７７９ｋｌ, ２６，０００ｋｌ exist （ Fuel height ： about 18 ｍ） Diameter ４２．７ｍ Height ２４． 4m Built in 1974 as crude oil tank Then changed for storage of naptha

naphtha No posibility for boilover because of 71 C for 95 ％ distilation Similar to gasoline, but lower boiling point Flash point ー２０℃ Burning rate is very high ； 5-8 mm ／ min （ m ／ hour ） Due to strong wind, it was higher.

Distilation curves (Naptha, Crude oil and gasoline) Crude oil Naptha gasoline Volume % Temperature C

Burning rate during the fire PeriodBurning rate(m/hr) Ignition - 4 hr hr - 8 hr0.50 These values are very large, normally m/hr for gasoline, kerosene Because naphtha is very light

４ :0 ５ AM, September ２９ Start of large fure fighting gun, 17 hours after start of the fire

9:32 AM Sep. 29

1:00 AM, September ２９

Tank Fall down, at 1:23 PM, September

2:06 PM, Sep. 29

2:07 PM September 29 Strong heat flux damaged fire engine

About 6:30 AM September 30

Tanks after the fire

Oil storagety storage base near Idemitsu Refinary, very little damage by the same earthquake

Problems in fire-fightings Not enough extinguish agent, because two fires occurred after the earthquake Commanding system is not good, because so many fire departments came Strong wind, tank height is high, so extinguish agent did not reach inside tank

Problems, use of foam extinguih agent Each fire fighter group has different agent Government: synthetic foam Idemitsu: AFFF, Protein Foam National storage base: Protein Foam USA military: AFFF

Conclusion To extinguish we need 44 hours, and most fuel was burnt out. Naphtha is so difficult to be extinguished Other problems, strong wind, height of tank is 24 m However, no human damage