I thought security clearances are a dime a dozen, and "all FBI employees" list is full of administrative work and basically 80% mirrored on LinkedIn? (Yes, the remaining 20% - or however much - leaking is a problem.)
Lol, just because a tool exists that in theory can be used to potentially do part of what it takes, doesn’t mean anyone will use it that way consistently or reliably.
Many of those installations end up abandoned when the cost to repair them exceeds the value of the output of the panel.
You just typically don’t notice it because unless the panel is severely damaged, a non-functional panel doesn’t look much different than a functional one.
Construction already uses cranes for longer spans than this. They already know how to brace them on dirt as well. There is nothing large about this - they need slightly larger machines than you would expect at first because they can't be right next to the ditch, but nothing that construction doesn't already deal with in other situations.
Cranes are expensive yes. However they are common, and the needed horizontal reach isn't that much. (I've been in construction where we needed cranes that big - generally a house will use a larger crane than a commercial building - the house a large crane can reach the back corner and so you don't need to move it, commercial you have to move the crane anyway so you save with a cheaper one). Note that I'm not talking about tower cranes which are very big but a whole different beast that I don't know.
I don't know the details of their plan, but I wouldn't design the reach over live electrical panels myself. The obvious thing is not lift individual panels, it is to lift a whole string of panels already wired up and connected to the frame.You have somebody on each end (which is on land) to put the bolts in, connect the last wires (which are live, but nothing electricians don't work on live all the time). Even if the worst disaster happens - nobody is ever under something falling and the live wires fall to the ground without harming anyone.
The above is not difficult. Well there are a few more details that need to be figured out, but they all fit in the above plan and are obvious to anyone who has been in construction.
My AEC experience has been that cranes are expensive enough that “everyone” does whatever they can to avoid needing them and when they need one they rent one.
Because cranes are expensive crane operators are expensive and crane insurance is high (because cranes kill people), crane companies only work economically because crane companies can stay busy.
But when you rent, your schedule is dependent on every other crane customer’s schedule. You get a crane only when one is available and odds are you are not the crane company’s best customer nor the customer with the deepest pockets to pay priority service rates.
In my AEC experience cranes get “surprisingly bigger” as horizontal reach increases…levers work that way.
By “surprisingly bigger” I mean without actual experience with crane tables…my first AEC job involved cranes and prestressed concrete in a business culture where employees had been killed with cranes. And I spent time in the yard where driveable gantries were handling big chunks of concrete “overhead”…by “overhead” I mean you could wind up under twenty kips if you weren’t careful and Carl didn’t know you were there.
You seem to be trying to refute me, but everything you said exactly matches my experience and what I'm trying to say. Your project managers and design should be such that you minimize your crane costs, and when it comes you get as much done as you can. Even though a crane is expensive, when used well their portion of the cost is tiny.
There are enough canals in CA that I would expect to be an important customer of the cranes. You don't get a crane on demand, but you can always plan such that when you get the crane there is plenty of work.
I don't understand what problem you're worrying about though. Others have already brought up the data center example where Google often will leave a server rack in place for five years even if some of the individual computers in it have failed. That is, it's easy to replace an entire rack at once than to replace just parts.
Similarly, for a system like this, I would expect they would build in components, let's call them racks of panels, however many that are connected together. If one of these so-called racks fails, leave it up until whenever and then replace the whole thing.
Possibly you'd have to remove a bunch of panels from the canal if the support's collapsed, but you should be designing them for the highest possible wind roll, but so that's unlikely to happen. Well, earthquakes are a problem, and I'm not sure how much you can design for that, but once again, you design for that. In any case, if something happens in a disaster, well, you may have to remove some panels from the water, but that's a labor job that needs a little bit of safety training. But otherwise, no crane. You just remove it and throw it away. You come back with the cranes later to repair the system back to where it should be. I'd be thinking using a tow truck for disaster recovery, not a crane.
It is routine all over. Construction is always a game of moving people and equipment where the work is. There are a lot of people in construction who never work in the same city for more than a year, they just live in a local hotel and move the crane as needed.
I suspect this is cheaper than many projects just because the work is consistent - once you have the canals covered you keep a crew around to repair/replace them. That is you will need one crew full time within 2 hours of some small town so you hire someone who is willing to live in that small town (they get to go home to their family every night unlike the construction crew above working in a different city every year)
Makes no difference. You schedule the crane when you need it. Just make sure there's enough to do that it's worthwhile for the crane to come out for the day's work.
Jordan Harris, once a Virgin Records executive who had a hand in turning acts like Paula Abdul and The Smashing Pumpkins into household names, now serves as co-founder and CEO of Solar Aquagrid. He says the $20 million Project Nexus has done much more than serve as simple proof of concept.
While yes, these are cheap for steel structures, calling them cheap overall is silly. They literally cost more than the canal under them to make (assuming basic earthmoving and concrete formwork), especially when you include the cost for the footers.
As a way to save water, maybe. But it makes no sense as a way to make electricity. Someone else did the math, and it was approx $10/watt, which is silly.
The steel and concrete have the same materials cost as steel and concrete for ground mounted panels.
The large scale members usually mean there is less labor cost and mobilization time, and hence overhead (insurance, fencing, trailer, etc.). Like I said pre-engineered metal buildings are about the cheapest cost per square foot you can get at scale.
The raw material cost for steel is by the ton. Barring unusual circumstances. And metal bents are very very structurally efficient.
Incidentally, they are not “I beams” and technically I-Beams are Wide Flange Shapes and used vertically as well as horizontally, and designated with as W(n)x(m) where W means wide flange, n is the depth in inches, and m is the weight in pounds per lineal foot. W shapes are rolled in rolling mills.
Bents are fabricated from steel plates to a design specific to the structure.
reply