[HN Gopher] Panama Canal Draught Restrictions Spark Liner Surcha...
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       Panama Canal Draught Restrictions Spark Liner Surcharges
        
       Author : Stratoscope
       Score  : 25 points
       Date   : 2023-08-08 20:50 UTC (2 hours ago)
        
 (HTM) web link (gcaptain.com)
 (TXT) w3m dump (gcaptain.com)
        
       | version_five wrote:
       | Wikipedia says this about the northwest passage:
       | Therefore, the Canadian commercial marine transport industry does
       | not anticipate the route as a viable alternative to the Panama
       | Canal within the next 10 to 20 years (as of 2004).
       | 
       | Curious if there is an update. Seems a no brainier for Canadian
       | sovereignty to invest in this, so I expect we won't.
        
         | icegreentea2 wrote:
         | What type of investment did you have to mind? Investments to
         | boost commercial viability? Or improvements to boost Canadian
         | sovereignty claims?
        
         | grecy wrote:
         | A friend is sailing it right now. There is still a good deal of
         | ice. It's almost a certainty to open every year now, but only
         | for 1-8 weeks, then it's blocked by ice again.
         | 
         | 20 years ago there was no guarantee it would open at all during
         | the summer.
        
         | sp332 wrote:
         | There are some extremely sensitive habitats up north. A spill
         | could be a disaster for some endangered species.
        
           | version_five wrote:
           | That's really a throw away answer. Is there something
           | concrete you want to share? As written it just sounds like a
           | lazy excuse for not engaging with something, which could have
           | been done by not commenting. I don't understand what the
           | point of even writing it was.
        
       | stickfigure wrote:
       | For anyone interested in how the new (bigger) locks use less
       | water than the old locks (reclaiming 60% of the water - without
       | pumps!), this old Practical Engineering video explains with
       | diagrams:
       | 
       | https://www.youtube.com/watch?v=SBvclVcesEE
       | 
       | They store the water in a series of basins at different levels,
       | and use those basins to fill the portion of the lock below. It's
       | more obvious with diagrams.
        
       | daveslash wrote:
       | Glad I read the article. At first I ( _naively_ ) thought _" why?
       | just pump more seawater?"_ But according to the article " _it
       | takes around 50 million gallons of fresh water to move a ship
       | through a lock. The panamax locks lose more fresh water than the
       | neo-panamax locks, which have a recovery system that can reclaim
       | 60% of the water_ " -- A spot check on the maps shows Gatun Lake
       | (freshwater) in the center of the isthmus. Wikipedia says it is
       | fresh, but human made.
       | 
       | Is anyone aware of the reason for creating the interior of the
       | canal as a freshwater passage, as opposed to just mixing ocean
       | water willy-nilly? Such mixing of water would probably not pass
       | current environmental concerns (with good reason), but curious
       | what the reasoning was from a 1913 perspective?
        
         | dragonwriter wrote:
         | FTA: "...the canal and the lakes and rivers that make up its
         | watershed, which also provides fresh water to three cities,
         | including the capital."
         | 
         | Presumably, "people actually need to live in the area, and
         | cannot drink salt water" was a factor.
        
           | iancmceachern wrote:
           | It's because the Panama canal was constructed by connecting
           | several previously naturally existing (fresh) waterways and a
           | big lake, to the ocean on both side. The whole point of the
           | locks is to raise and lower the ships to the higher elevation
           | at which the lake sits. Water runs downhill, it starts as
           | rain, then to rivers and lakes, then the ocean. So in this
           | case rain and natural watershed basins drain into the lake
           | and then the locks release it slowly down to progressively
           | fill each lock, until the water is at the ocean, at which
           | point it can't efficiently be separated from the seawater, so
           | it just becomes part of the ocean.
           | 
           | The people there drink the fresh water and chose to settle in
           | that area originally because ot was there. We then built a
           | canal after. It wasn't like we built the Panama canal as a
           | water source for the local folks.
        
             | dragonwriter wrote:
             | > It wasn't like we built the Panama canal as a water
             | source for the local folks.
             | 
             | Right, I am saying that the effect it would have on the
             | existing water source is a probably a factor in why "allow
             | more free mixing of saltwater / pump more seawater to deal
             | with drought conditions impacts on the canal" is not done.
             | 
             | Not that the Canal was built as a water supply.
        
         | michael1999 wrote:
         | From the article: "This was to reduce salination of the
         | freshwater in the canal and the lakes and rivers that make up
         | its watershed, which also provides fresh water to three cities,
         | including the capital."
         | 
         | Panama City is pretty thirsty.
        
         | jrvarela56 wrote:
         | This is how they made the lake:
         | https://en.wikipedia.org/wiki/Gatun_Dam
         | 
         | I'm assuming flooding the other way around was more expensive
         | than creating a fresh water reservoir by building a dam.
        
         | pseingatl wrote:
         | One of the reasons was to control the Chagres River. The
         | creation of Gatun Lake created a freshwater reservoir higher
         | than sea level. Vessels enter the Canal, climb up to the level
         | of the Lake and are dropped back down to sea level. I have to
         | wonder if the third set of locks (what I think they're calling
         | Neo-Panamax locks) uses more water than the original 110 x 1000
         | locks. There must be a way to recycle water for use in Panama
         | City and Colon. It's not practicable to re-use the water for
         | canal operations because the water would have to be raised back
         | up to the level of Gatun Lake and it would take an enormous
         | amount of energy to do so. As I recall, spillage from canal
         | operations was never used to generate electricity, but that
         | might no longer be the case.
        
         | kgermino wrote:
         | Salinity issues aside, in my understanding locks generally
         | don't pump water at all: they work entirely on gravity. In
         | effect this means that a burst of water flows downstream every
         | time the lock is cycled.
        
           | pseingatl wrote:
           | Correct.
        
           | iancmceachern wrote:
           | Exactly, they basically harness the natural water cycle (rain
           | to watersheds to waterways to ocean).
           | 
           | The one exception is with these new locks, I bet they pump a
           | bunch of the water back now instead of releasing it, that's
           | how I expect they get the 60%.
        
             | Animats wrote:
             | Nope, it's not pumped. It's a clever system where there are
             | several storage basins at different levels.[1]
             | 
             | In the 1960s and 1970s, there was a nuclear reactor mounted
             | on a ship to provide power for the Panama Canal. This
             | reduced water loss via the hydroelectric plant at Gatun
             | Dam, leaving more water for the locks.[2]
             | 
             | [1] https://en.wikipedia.org/wiki/Panama_Canal_expansion_pr
             | oject...
             | 
             | [2] https://en.wikipedia.org/wiki/MH-1A
        
               | iancmceachern wrote:
               | Truly incredible, thank you!
        
         | lokar wrote:
         | Much of the route is pre-existing river and lake, the whole
         | thing is an extension of a watershed.
        
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       (page generated 2023-08-08 23:00 UTC)