It's about more than the pumps

For those of you coming here to read about the rusty pumps, that entry is directly below this one. But there's more to the lakefront gates than just the pumps, even though they are a big part of the story.

A while back I wrote a number entries about the design and construction flaws other than the rusty, underdesigned pumps at all three lakefront gate structures. The structures were constructed in 2006. The problems are legion:

- the current gates do not meet the Corps' own design criteria for height to protect from storm surge

And to save money, the Corps decided this past May to pull the same trick with the future permanent pump stations, dropping their elevation to 16 feet above sea level, 2 feet below what Corps design guidelines require.

- the concrete trenches - into which the gates are placed before a storm - suffer from design and installation flaws. They are lined with uncoated carbon steel, which does not stand up to the brackish water in Lake Pontchartrain. In addition, two of the sites had concrete grout fill the trenches during construction which had to be jackhammered out, leaving the condition of those trenches - and their ability to transfer the load imposed by storm surge from the gates to the soil below - in question.

- the needle gates themselves and the vertical guides in which they travel do not meet Corps requirements for how such components should be made, and are far less beefy that those guidelines call for.

- the gates are either weakly sealed against water leaking around them (17th Street), or are not sealed at all (Orleans and London Avenues).

- the winches that raise and lower the gates, as well as their controls, are not protected from getting hit by wind-borne debris. In fact, some of their control boxes are placed on the storm side of the gates:


- operators of the gates have left them unsecured during storm events:


This photo was taken on September 12, 2009, after the London Avenue gates were closed. Zooming in:


This shows that at least four pins - and the gates they hold down - were unsecured during this storm event.

But perhaps the most troubling thing wrong with the gates is the apparent near total lack of lightning rods across all three sites.

In 2009, the Corps received a report about the Interim Closure Structures. It detailed problems with the sites that needed to be addressed in order for the sites to remain usable until the permanent pump stations come on line in a few years. The main emphasis of the report was the rampant corrosion throughout the sites, and I will write about that soon. Some of the corrosion is apparently so bad that revealing its exact location would compromise national security. That is, the Corps actually redacted information from this report because of the sensitive nature of the ongoing damage to the structures.

But that's less urgent than this:

"6) At the 17th Street site the west engine platform has a lightning protection system in place as seen Figure 3.1. However, lightning protection systems were not evident on the east engine platform (Figure 3.2), the direct drive pumping platforms (both east and west), or the gate structure (Figure 3.3).
7) The London Avenue site has a lightning protection system in place on the gate structure as seen in Figure 3.4. However, other structures at the facility do not appear to have lightning protection system in place (Figure 3.5).

8) The Orleans Avenue site does not appear to have a lightning protection system in place. As an example, none can be seen on engine platform located on the west side of the canal as seen in Figure 3.6."

Here's figures 3.1 through 3.6, indeed showing a lack of lightning rods across all three sites:

The final picture shows the true hazard: no lightning rods on the fuel tanks or the buildings next to them. All the pumps are powered by diesel fuel, so there are storage tanks at every site:

As you can see, the Orleans and London Avenue sites both sit within residential neighborhoods.

Now, there may be some other kind of lightning protection system that was not visible to the electrical engineer that wrote the portion of the report commissioned by the Corps. However, it seems like a problem to my untrained eye.

The Corps' preference for the power source of the future permanent pumps: diesel.