Panama Canal Expansion

[Playinghardball]

The Panama Canal Expansion is the largest project at the Canal since its original construction. The project will create a new lane of traffic along the Canal through the construction of a new set of locks, doubling the waterway’s capacity. The existing locks allow the passage of vessels that can carry up to 5,000 TEUs. After the expansion the Post-Panamax vessels will be able to transit through the Canal, with up to 13,000 TEUs. The Expansion will double the Canal’s capacity, having a direct impact on economies of scale and international maritime trade.
The Program consists of several components:

• New Locks (Third Set of Locks)
• Pacific Access Channel
• Improvement of Navigational Channels (Dredging)
• Improvements to Water Supply
The Panama Canal expansion is based on six years of research, which included more than 100 studies on the economic feasibility, market demand, environmental impact and other technical engineering aspects. Works on the Panama Canal Expansion began on September 2007 at a total cost of US$5.2 billion.

http://micanaldepanama.com/expansion/

[jberryhill]

1. "Improvements to Water Supply"

That's the rub.

It's not just some ditch across Panama, but requires a lot of water in order to fill the locks and raise the ships. The water doesn't go back uphill once used.

[sdfernando]

2. That is definitely true with the old construction

I used to be quite fascinated with the canal as I lived in the Zone when I was in just starting grade school.

My understanding with the new construction is that water will be recycled. I'll have to look into it more deeply.

[jberryhill]

3. The water runs downhill

The only way to recycle it is to make it go uphill.

Now, if they import water from New Zealand, that might work, since it goes the other way.

[sdfernando]

4. That's what pumps are for

To make water go uphill. Now they still have some water that gets wasted but not nearly as much as when the old system was in place.

[jberryhill]

6. And what runs the pumps?

It takes as much energy to lift the water which the ship displaces as it would take to lift the ship. That's basic physics.

http://en.m.wikipedia.org/wiki/Gatun_Lake

"Each time a ship transits the canal 202,000 m3 (53,400,000 US gal) of water is passed from the lake into the sea; with over 14,000 vessel transits per year, this represents a very large demand for water."

Now, that's 53 million gallons per ship through the presently-sized locks. Building the dams for the water supply was itself a substantial project, with significant impact.

These pumps are going to have to be powered by something, and it isn't going to be hydroelectricity for obvious reasons.

[sdfernando]

8. Doing a little research I see they are basically using the same system with modifications.

Yes, in the old systems the water used to raise and lower the ships transited the the three lock chamber levels via culverts and in the final lock the water would be sent out to the sea. In the new system they are using the same principal, allowing gravity to equalize the water levels between lock chambers...but the culverts redirect the water to catch basins rather then out to sea. This method saves 60% of the water that would normally be wasted.

[tsites]

7. Water Saving Basins

Rather than simply dump water downhill and eventually into the ocean, part of the water is diverted into adjacent temporary storage. This water can then be used to partially fill each lock as they raise ships in the locks. This is all gravity fed - no pumping. This results in the new larger locks using slightly less water than the older locks per passage even though they are three times the size.

[psychopomp]

5. This is an anticipatory response to the China-Nicaragua canal project

http://en.wikipedia.org/wiki/Nicaragua_Canal