It's all speculation yet but it could have meant to serve as a fake reason for a derailment. As in, "witnessess saw fire from an explosion under train when it derailled..." Who knows.
Casted pipe certainly sends more shrapnel but if we're trying to derail a train we don't even need metal or PVC. Enough cardboard and black powder would work (think giant M-80).
It's all speculation yet but it could have meant to serve as a fake reason for a derailment. As in, "witnessess saw fire from an explosion under train when it derailled..." Who knows.
Casted pipe certainly sends more shrapnel but if we're trying to derail a train we don't even need metal or PVC. Enough cardboard and black powder would work (think giant M-80).