07-16-2023, 05:37 PM
A lightshow that ended when up to 350 drones ditched into
Melbourne’s Yarra River has sparked concerns about how
environmental risks were managed as efforts got underway
to retrieve hundreds of lithium batteries from the water on
the weekend.
The operator, Australian Traffic Network, confirmed the company
had lost around 350 of its drones and was still investigating
what went wrong. The drones did the correct(!) thing by entering
auto-land and hitting the water when they encountered the
glitch and there was never any safety risk to the public.
These 1856-3.7V lithium-ion cells create an extreme hazard when
dumped into water as the lithium reacts with the hydrogen ions
(H+) in the water, producing hydrogen gas and lithium hydroxide.
This reaction is exothermic, which means it releases heat, and it
eventually ignites and burns under the water (thermal runaway).
It also means that all these submerged cells should be recovered
in, say, 12 hours, before they start leaking toxic chemicals. The
total amount of lithium in the lost cells would be approximately 10kg.
This is an 18650 cell shown actual size:
If anybody seriously believes that divers are going to recover 350 of
these relatively tiny objects from the muddy, tidal bottom of the river,
they're dreaming. That's just a bullshit defence from the lightshow
operators, and will never happen in practice. I guess if the cells are
still in their holders it'll make it easier in locating entire drones.
EPA Tier 2 offences are set out according to the medium involved. Water
pollution is prohibited under section 120 (previously section 16 of the
Clean Waters Act). The maximum penalties for Tier 2 offences are
$1 million in the case of a corporation, and $250,000 in the case of an
individual.
Will be interesting to see what fines—if any—are issued to the lightshow company.
Melbourne’s Yarra River has sparked concerns about how
environmental risks were managed as efforts got underway
to retrieve hundreds of lithium batteries from the water on
the weekend.
The operator, Australian Traffic Network, confirmed the company
had lost around 350 of its drones and was still investigating
what went wrong. The drones did the correct(!) thing by entering
auto-land and hitting the water when they encountered the
glitch and there was never any safety risk to the public.
These 1856-3.7V lithium-ion cells create an extreme hazard when
dumped into water as the lithium reacts with the hydrogen ions
(H+) in the water, producing hydrogen gas and lithium hydroxide.
This reaction is exothermic, which means it releases heat, and it
eventually ignites and burns under the water (thermal runaway).
It also means that all these submerged cells should be recovered
in, say, 12 hours, before they start leaking toxic chemicals. The
total amount of lithium in the lost cells would be approximately 10kg.
This is an 18650 cell shown actual size:
If anybody seriously believes that divers are going to recover 350 of
these relatively tiny objects from the muddy, tidal bottom of the river,
they're dreaming. That's just a bullshit defence from the lightshow
operators, and will never happen in practice. I guess if the cells are
still in their holders it'll make it easier in locating entire drones.
EPA Tier 2 offences are set out according to the medium involved. Water
pollution is prohibited under section 120 (previously section 16 of the
Clean Waters Act). The maximum penalties for Tier 2 offences are
$1 million in the case of a corporation, and $250,000 in the case of an
individual.
Will be interesting to see what fines—if any—are issued to the lightshow company.
