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The Flexport CEO said it was an LNG (Liquefied Natural Gas) carrier. https://x.com/typesfast/status/1724150162531201571?s=20 https://x.com/typesfast/status/1724

by mdeeks 3y ago

The Flexport CEO said it was an LNG (Liquefied Natural Gas) carrier. https://x.com/typesfast/status/1724150162531201571?s=20 https://x.com/typesfast/status/1724150162531201571?s=20 Keep an eye on whats going on at the Panama Canal. An LNG carrier just paid $4 million to jump the line. This will likely be more common for LNG carriers as their cargo will literally boil off sitting in the hot tropical sun, but it will be interesting to see if container ships end up having to resort to similar measures as transits continue to be restricted due to the ongoing severe drought.

londons_explore 3y ago
Presumably LNG ships have recondensors so they can burn some small proportion of the gas to power engines to run chillers to keep the rest cold?
- gosub100 3y ago
  > some small proportion of the gas probably about $4MM/(anticipated duration of long wait) =)
Smoosh 3y ago
You would think that $4 would pay for some excellent refrigeration equipment. I wonder what the engineering compromises are for the LNG storage on these ships.
- fuzzfactor 3y ago
  The chillers are a lot more than $4 million, more like billions, they are huge and located on shore or offshore at the point of loading: https://www.econnectenergy.com/articles/how-does-an-lng-plant-work https://www.econnectenergy.com/articles/how-does-an-lng-plan... LNG is almost all methane which is the lightest hydrocarbon. Methane is so light a gas that it does not liquefy even under thousands of PSI of compression. And at room temperature it only practically exists in a gas form, pressurized or not, so in that case it needs to be handled like oxygen or nitrogen, other light gases where the heavy-walled steel storage cylinders weigh more than the contents even at maximum pressure. You just can't get that many kilos of such light molecules into a certain space as a compressed gas compared to how dense a liquid gets. So they liquefy the gas instead before transport and that requires cryogenics rather than pressure. The chilled liquid can then be stored or transported in tanks of much thinner-walled steel since gas pressure is not a major issue. These low-pressure tanks are thickly insulated with lightweight materials to keep in the cold as much as possible. And unlike the heavy-walled things like the welders use for their pressurized oxygen, cryogenics are handled like the tanks of liquid oxygen, where you can't completely close the cryogenic storage tanks or pressure would build up beyond the bursting point of their relatively thin-walled construction. The cryogenic tanks are constantly hissing as they release excess gas for this reason. Since no insulation is perfect, the cargo does pick up heat gradually and this causes a certain amount of steady boiloff. Rather than physically becoming warmer, the cargo self-refrigerates by evaporation. Basically they are loading metric shiploads of really cold LNG and it just slowly evaporates as they go. The cargo temperature is kept constant by self-refrigeration where the condenser is the plant on shore and the evaporator is the ship on its way at sea.
marklubi 3y ago
I haven't found any other collaborating articles, but this one says that it was an empty gas carrier. > The prospects of a growing wait reportedly prompted one company to bid a record $4 million for one of the open slots bringing their anticipated total transit costs to $4.5 million and still they have to wait another week to get their empty gas carrier on its way. https://maritime-executive.com/article/panama-canal-auction-sets-record-4m-for-slot-as-congestion-grows https://maritime-executive.com/article/panama-canal-auction-... Later in the article, it says that they might give up their bid, which sounds to me like they had contracts that needed fulfillment with expensive penalties. Probably made the bid to hedge their bets, and are working right now to renegotiate penalties to account for unforeseen circumstances.

by mdeeks 3y ago

londons_explore 3y ago

Presumably LNG ships have recondensors so they can burn some small proportion of the gas to power engines to run chillers to keep the rest cold?

gosub100 3y ago
> some small proportion of the gas probably about $4MM/(anticipated duration of long wait) =)

Smoosh 3y ago

You would think that $4 would pay for some excellent refrigeration equipment. I wonder what the engineering compromises are for the LNG storage on these ships.

fuzzfactor 3y ago
The chillers are a lot more than $4 million, more like billions, they are huge and located on shore or offshore at the point of loading: https://www.econnectenergy.com/articles/how-does-an-lng-plant-work https://www.econnectenergy.com/articles/how-does-an-lng-plan... LNG is almost all methane which is the lightest hydrocarbon. Methane is so light a gas that it does not liquefy even under thousands of PSI of compression. And at room temperature it only practically exists in a gas form, pressurized or not, so in that case it needs to be handled like oxygen or nitrogen, other light gases where the heavy-walled steel storage cylinders weigh more than the contents even at maximum pressure. You just can't get that many kilos of such light molecules into a certain space as a compressed gas compared to how dense a liquid gets. So they liquefy the gas instead before transport and that requires cryogenics rather than pressure. The chilled liquid can then be stored or transported in tanks of much thinner-walled steel since gas pressure is not a major issue. These low-pressure tanks are thickly insulated with lightweight materials to keep in the cold as much as possible. And unlike the heavy-walled things like the welders use for their pressurized oxygen, cryogenics are handled like the tanks of liquid oxygen, where you can't completely close the cryogenic storage tanks or pressure would build up beyond the bursting point of their relatively thin-walled construction. The cryogenic tanks are constantly hissing as they release excess gas for this reason. Since no insulation is perfect, the cargo does pick up heat gradually and this causes a certain amount of steady boiloff. Rather than physically becoming warmer, the cargo self-refrigerates by evaporation. Basically they are loading metric shiploads of really cold LNG and it just slowly evaporates as they go. The cargo temperature is kept constant by self-refrigeration where the condenser is the plant on shore and the evaporator is the ship on its way at sea.

marklubi 3y ago

I haven't found any other collaborating articles, but this one says that it was an empty gas carrier. > The prospects of a growing wait reportedly prompted one company to bid a record $4 million for one of the open slots bringing their anticipated total transit costs to $4.5 million and still they have to wait another week to get their empty gas carrier on its way. https://maritime-executive.com/article/panama-canal-auction-sets-record-4m-for-slot-as-congestion-grows https://maritime-executive.com/article/panama-canal-auction-... Later in the article, it says that they might give up their bid, which sounds to me like they had contracts that needed fulfillment with expensive penalties. Probably made the bid to hedge their bets, and are working right now to renegotiate penalties to account for unforeseen circumstances.