Thread by @Matthew67052126

Finally, @SWBNewOrleans has treated its customer base with respect and put out a ton of information about their systems ahead of tonight's rain. But it's doubtful most people will see it today, so I will hit the highlights. (1/22)

The @NOLACityCouncil had a meeting scheduled for tomorrow where @SWBNewOrleans was due to present. The meeting was postponed to Monday, but the postponement came late enough that all the slide presentations were uploaded to the Council website: (2/22) cityofno.granicus.com/GeneratedAgend…

The logistics of the meeting are of less interest than its content. I personally have been waiting days to see the attachments to the agenda, and the S&WB one does not disappoint: (3/22) cityofno.granicus.com/MetaViewer.php…

The S&WB slides include some standard ones they have used, but there are a bundle of new ones, and that's what I want to focus on. It is clear orders have gone out within the Board to lean forward in supplying public information about publicly funded assets to the public. (4/22)

First up are details on when @SWBNewOrleans claims their current seven out of service pumps will come back. Their propensity for jargon is unfortunately intact. Since they don't say so, I will inform you "RTS" stands for "Return to Service." (5/22)

They added station capacities and the impacts of the pump losses, information that I am usually the only one to put out. They have massaged it a bit, counting non-storm duty constant duty pumps in the DPS 4 & 13 totals (80 and 50 cfs respectively), but that's minor. (6/22)

The four New Orleans East pumps have been out for a long time, and the return dates are likely speculative. Their outages, while significant, are mitigated by the large open area in the east and other pumps still in service. The Algiers pump is a lost cause. (7/22)

The two pumps of concern are the ones at DPS 4 and DPS 19. I wrote about the DPS 4 outage on June 17 and why it matters. S&WB Gen'l Superintendent Steve Nelson also highlighted DPS 4, which drains Gentilly, as a concern at today's Board meeting. (8/22)

https://x.com/Matthew67052126/status/1935169808124825912

S&WB included pics of the two pumps that are out, pump "H1" at DPS 19 and pump "E" at DPS 4 (9/22)

Other than red danger tape strung up alongside it, I can't see anything happening on the pump at DPS 19. However, the picture of DPS 4 pump "E" is very instructive. It shows the problem is with one of the bearings. (10/22)

In 2019, S&WB replaced both bearings on each of the 3 major pumps (C, D, E) at DPS 4, including the pump "E" inboard one which is clearly now out for either repair or replacement. It is supposed to be on the shaft here, to the left of the impeller (water flows left): (11/22)

The specs for that 2019 contract, worth $3.2 million to frequent S&WB contractor Conhagen, called for not only bearing replacements, but also supply of spare bearings. It is unclear if the current repairs consist of installing a spare, or repairing the broken bearing. (12/22)

It is important not to focus on how many pumps @SWBNewOrleans claims are "available." That only means that pumps can be run without any load. It says nothing of how they will perform in a storm. On average, 20-25 pumps go down for some period during a typical big storm. (13/22)

Moving on to power, there has been a lot happening today. The top headlines are that 60 Hz turbine T6 has returned to service nine days early, and that turbine T4 has been turned on. (14/22)
swbno.org/Projects/Pumpi…

I spilled a lot of ink about T6 earlier this month. The rapidity with which the unit returned backs up how critical its failure was. It mainly powers the east bank water system when S&WB goes off of @entergynola power during high wind events. (15/22)

https://x.com/Matthew67052126/status/1942316108817785008

T4 was brought online via load transfer from T5 earlier today. That they were able to do so at all is surprising, since T4's most frequent mode of failure is during such transfers. That still could happen during a storm as loads go up and down. (16/22)

The reason for such failures is the S&WB chose to keep a couple of big steam valves on T4 rather than replacing them when they had the chance post-Katrina. The valves can't respond quick enough to load changes, so the turbine trips. At least once, it nearly exploded. (17/22)

The April 2023 T4 near explosion happened when the valves didn't shut when the turbine started overspeeding after a transfer from T5. Operators had to shut off the steam flow manually, likely risking their lives. The blast could have destroyed the S&WB powerhouse. (18/22)

T4 got to near 2000 rpm, far above its normal running speed of 1500 rpm. Multiple emergency stop buttons failed. It had to be terrifying. I only found out about it through public records requests. (19/22)

Since T4 is so sensitive to load changes, I find it unlikely it will provide much power during this event. T5 will probably still be the workhorse. It will be a delicate thing when they spool up T5 and transfer some of T4's load to it. (20/22)

I won't detail how the S&WB estimate of 67.5 MW of "available" 25 Hz power is wildly optimistic, since everyone is already aware of how often their power assets fail during storms. It's pretty likely when actual load is put on any of the 11 machines. (21/22)

I'll leave comments on the section of the presentation about the new power complex for later, since it's not relevant to events today. Suffice to say these slides provide more info to the public than has ever been shown, except to vendors. It's about time. (22/22)