2021/09/28

T3 car accident in the Y-arm.

Reports are here.
Accident situation (13:10, 28th September, 2021)
Place: 1845m in the Y-arm, So, Two drain pipes are situated on the wall side.
Moving direcrion: from the center to Y-end.
Driver: Kimura-san, Passenger Seat: one Tori-sha member, Two tori-sha members are on the loading platforms ( I guess the total mass was over the spec of 100kg)
The left side rear-tire hit the pole for the drain pipes at the speed of ~ 20km/hour, then the car rotated the counter clock wise direction, then the car head crashed into the drain pipes.

One of two members on the loading platform seems to hit directly on the duct "near the bellows". Then he innevitably seemed to push out the other members towards the drain pipes. Fotunately, the metal bars on the loading platform seemed not to hit the duct directly, because it height is lower than the bottom of the duct. The driver and one tori-sha member on the passenger seat hit their bodies in the narrow space.
All members suffered from bruise(打撲). One of them claimed uncomfortable in his leg.
Kimura-san called Takahashi-san to rescue the Tori-sha members to take to a hospital by using the other T3 in the tunnel.
All members were checked at the hospital and were judged to suffer from bruise, but no serious damege such as bone break.
The crashed T3 could move, so someone carefully drove it back to the center area.
No leask was detected in Y-arm.

After care (対応)
maybe Ohashi-san explained this situation to Tori-sha itself, and the tori-sha checked the on site people situation by himself.
Ohashi-san stopped the CRY schedule until the judge from the Tori-sah whether they can continue or also stop. (The important thing is that you should not decide the future action among you and the on site commercial members in such a case)
The Tori-sha told us that he want to have them continue the planned tasks.
Then, we restarted the CRY tasks from PM on 30th September.

Relapse prevention (再発防止)
Don't be on the loading platform, except for the specially cared case.
We will prepare reflectors on the duct and the drain pipe sedes in Y-arm. X-arm already has them triggered by also an accident in which someone hit a vacuum related sticking out part.
We don't put enough lights one of because the bright/dark contrast rather let you see less the dark area because the center of light (brigher area) makes your pupils (瞳孔) smaller.

How is the crashed T3 ?
The simple on site check was done. It is necessary to repair the frame after taking out from the KAGRA tunnel.
We will buy a new one. While, we are now wondering whether the crashed one shold be repaired or not, and to be used for example in X arm or KAGRA entrance tunnel.
Or, we are also considering electrical kickboards for more easy and safely transportation tools.