Programmers occasionally have envy that civil engineering is "real engineering", e.g. civil engineers know how to build a bridge and deliver it on time. Whereas software engineers will come up with 1000 ways to build the bridge, 10 of which work, and take 10x longer to build it. This article seems like a good counterexample.
Like most failures, this is a systems failure. Someone engineered the hell out of that cable. But they neglected to realize that it would be drawn through a steel pipe.
"So, what went wrong? Varying load conditions in the three legs of the 3-phase circuit caused tremendously strong and dynamic magnetic field changes. The electromagnetic forces between the three conductors and the steel pipe (gack!) cause the conduit to wiggle around inside the pipe."
The other lesson is that you shouldn't hyper-optimize locally, and instead design for maintainability. I'm not sure what they were thinking when laying a cable that requires experts to be flown in from the east coast to repair. The simplest mechanisms are the ones that are the most easily repaired. The entire article goes on in great length about how awe-inspiring the engineering of this cable is, whereas I just see a bunch of complexity that probably didn't need to be there. The 118 layers of paper tape, and the oil pumps, and so forth. Surely there was a simpler solution. I'm sure after this failure and the ones on the east coast, they are not still laying cables like this.
The entire article goes on in great length about how awe-inspiring the
engineering of this cable is, whereas I just see a bunch of complexity that
probably didn't need to be there. The 118 layers of paper tape, and the oil
pumps, and so forth. Surely there was a simpler solution.
Take care that you don't come down with "Engineers' Disease", though - the
tendency for people with a high level of technical knowledge to decide that
their knowledge must be applicable to specialised fields that they don't
actually know a lot about.
You are a programmer, not an electrical engineer. Wild speculation regarding a field you know little about is not attractive.
Allow me to reverse your statement.
"I don't see why programming for multicore processors has to be so complex. Why not just run four copies of the program on all four cores?"
"I don't see why every web site makes you create a new account. Why not log into everything with my facebook account?"
"I don't see why the legal system has to be so complex. Why not just have the judge decide everything, and get rid of the lawyers?"
Message passing is more robust than the currently prevailing shared memory + thread spaghetti practice. Many/most problems being attacked with the latter approach can be reformulated to use message passing and looser coupling.
Calling out parent's incompetency is fair I guess, although we still don't know why it was necessary to engineer a cable so much only to find out it has basic flaws, hence the assumption it is over-engineered in certain aspects and under-engineered in others.
"I'm not sure what they were thinking when laying a cable that requires experts to be flown in from the east coast to repair. The simplest mechanisms are the ones that are the most easily repaired."
In this case, the simplest mechanism would probably have been to build above-ground high tension power lines on massive steel towers. This is the most common mode of high voltage electrical transmission, and the cables are easy to access and repair. However, this cable was probably built when the area was already densely populated, and property owners would not have accepted having such an eyesore going through their back yards. So they had to bury it underground, which required heroic engineering to insure that it would only have to be maintained very rarely (designed for an MTBF of 60 years).
There are analogous problems in computer hardware. For example, if you want a computer to control a cardiac pacemaker, you can't just buy a generic server and throw a gigabyte-sized Linux distribution on it. It has to fit in a tiny space, run for years on a small battery and be 100% reliable. Very different from creating a web application, but the extra complexity and expense are necessary due to the problem that's being solved.
"easy to access and repair" in this context might involve ckimbing out of a helicopter onto live half million volt lines in a space age chainmail suit:
"In this case, the simplest mechanism would probably have been to build above-ground high tension power lines on massive steel towers. This is the most common mode of high voltage electrical transmission, and the cables are easy to access and repair. "
astonishing that they don't do this. Their first attempt failed; the second likely will also. And both at tremendous expense when a tried-and-true methodology exists.
At the time the cable was installed (72ish?) 230kV was a very high voltage cable. The type of cable that now commonly carries that voltage underground is HV XLPE
I don't know about this automatic rejection of complexity. It could very well be that, even accounting for the tough learning curve and the cost of repairs, it's still the cheapest way to transmit that much power in that context.
Sometimes massive infrastructure requires massive repairs, but that doesn't automatically make it not cost-effective.
An always interesting facet to these types of stories is the ambivalence I feel for the people involved. While I would love to have a problem to tackle that is large enough, similarly unique enough to solve that it would make my career, I would have a problem large enough, similarly unique enough to break my career.
As another commenter mentioned, the engineering involved in the story is likely not required very many places on earth. To be in a situation, developing a solution to a massive problem with little to no precedence is an exhilarating and terrifying position to be in. It may sound overly-engineered to you but, at the time, it may have been the most cost effective engineering solution to a problem rarely encountered.
I didn't know this, I can see how a house appliance might consume several dozens of amps but 100 to 200 amps? Wow, that is a lot. I don't have much knowledge about power transmission (which is one of the most fascinating fields in electrical engineering, in my opinion) so I'll take your word for it.
You can have a small crappy house/apartment with 40-60A service, for sure. But electric appliances (hot water heaters, clothes dryers, ovens/ranges, etc.) can be 50A.
A single excellent commercial electric wok is about 50-100A.
Each individual circuit is about 15-20A.
The really awesome thing now seems to be HVDC transmission -- eliminates capacitance problems and problems with multiple grids.
> The really awesome thing now seems to be HVDC transmission -- eliminates capacitance problems and problems with multiple grids.
This. Imagine a global grid connecting alternative energy sources for each optimal locale: Geothermal in Iceland, Solar in North Africa, and of course Thorium in Norway.
Peter Thiel seems to think this scenario is improbable[1] but I don't think it takes into account ABB's recent breakthrough with HVDC switching[2].
> Someone engineered the hell out of that cable. But they neglected to realize that it would be drawn through a steel pipe.
This is about the most arrogant, ignorant thing I've read on HN. No. I promise you the electrical engineer who designed that feeder did not "neglect to realize" that a steel pipe is conductive and if the feeder came into contact with it, it would short. There were no doubt a number of considerations and trade-offs involved in the choice of material.
"So, what went wrong? Varying load conditions in the three legs of the 3-phase circuit caused tremendously strong and dynamic magnetic field changes. The electromagnetic forces between the three conductors and the steel pipe (gack!) cause the conduit to wiggle around inside the pipe."
This is sort of like the electrical engineering equivalent of the Tacoma Narrows Bridge collapse:
Fascinating to look back at the reactions from when I posted this 500 days ago. One person said:
while this is a classic, my snark is thrashing against
its bonds. I could have sworn it said 'news' up there.
And another:
SENSATIONAL HEADLINE ALERT!!!
And that was it. No further comments to be had. Both those comments were downvoted, but even so, interesting that no one else commented, and very few voted for the submission.
For reference, the headline I used was:
Engineering pornography - underground
power cables gone wrong
... which I felt was more informative.
So on this submission, now even older, we have 16 comments (and counting) and 60 points (and counting). Has HN changed? I'm off to check some records ...
(pause)
A bit of hunting shows that this got at least one vote while still on the "newest" page, but it looks like it never hit the front page, which will part explain why it never got many comments or votes. Still, the tenor of the comments is interesting. I continue to learn.
As what becomes popular on HN has a large dosage of randomness, I would not draw conclusions based on this one data point.
There was an interesting study from a few years ago that investigated what factors make a song a hit. They seeded various songs with various levels of initial popularity, and their general conclusion was that popularity begets popularity. Hence, initial conditions matter a lot, and they are largely random. (And if anyone can find that study, please let me know. I have tried multiple times to find it, but I can't.)
I read about a similar experiment in the book "Automate This" by yc alum Christopher Steiner. They seeded a music website with unknown songs and it turned out that whatever was liked first benefited from the Matthew Effect. ie, people tend to like whatever is already labelled as "popular". Definitely an interesting study, but I fear we've gone far off topic.
Yes it does have a large dose of randomness, and I'm not taking this single data point. I have more data. Quite a lot, actually.
And the challenge in the analysis is to find the factors that affect it, and then add the randomness to get the right results. To find the underlying behavior, even when the data are affected by randomness. It is kinda what I do, and that's partly why I'm working on it. I'm learning things as I go, both about the techniques and methods, and about the HN "community".
Interesting study you mention - I've made a note both to look out for it, and to let you know if I find it.
These are the droids that are being referred to I think:
http://www.princeton.edu/~mjs3/musiclab.shtml
"Experimental study of inequality and unpredictability in an artificial cultural market."
So you are complaining that you didn't get the karma 500 days ago that wallflower got? Or are you just pondering the mysteries of stories getting picked up? I see it isn't the latter since in this comment http://news.ycombinator.com/item?id=4097127 you indicate you've done research on that topic.
So you are complaining that you didn't get the
karma 500 days ago that wallflower got?
Not at all. Karma is a proxy measure for something else, and since this submission proved "successful" by the karma measure, I'm happy to see that the submitter got the karma for it.
Or are you just pondering the mysteries of stories
getting picked up?
In part, yes, exactly this,
I see it isn't the latter since in this comment
http://news.ycombinator.com/item?id=4097127
you indicate you've done research on that topic.
I have, and continue to do so because I have, as yet, come to no definitive conclusions. The investigations continue, even if only in a sporadic fashion,as and when I have the time.
So what are you saying?
I'm saying that sometimes submissions fail to attract any attention, even if subsequent submissions achieve significant success. This is evidence that the current system is, by some measures, sub-optimal. I continue to investigate the dynamics (as best I can), and continue to work on something that I think will improve the situation.
The dissonance between the comments there (even though downvoted) and the positive reaction here is also of interest. I thought I'd share that, hence my comment.
> This is evidence that the current system is, by some measures, sub-optimal.
Aren't you assuming the value of an article is a constant? In practice, context changes and the value of an article goes up and down. Maybe today is a slow news day and 500 days ago was very busy. I wouldn't expect your average article about (say) Scala to do equally well on the day Facebook has its IPO and some day nothing interesting happened on. A controversial article about gun control is not going to be perceived as having the same value the day after a big massacre as leading up to an election or on a boring day in mid-January.
An interesting point. As it happens, when it was submitted 500 days ago it was a slower day (in some sense) than today. The "newest" page had fewer items per hour back then.
It's an interesting observation, though, that for some items the "value" changes over time. This particular item, I suspect, doesn't fall into that category. Context might be more important, but the analyses I do try to take that into account.
Eh, it's starting to sound like sour grapes again. There isn't an objective standard for value you can discover if your analysis is just a little better.
You're right that there isn't an objective standard for "value" (or at least, I don't know one, nor how to get one), but multivariate analysis can assign a number to an item which is broadly aligned with my intuition of the concept of "better". As a result, I'm trying to home in on finding items that my system predicts should be "of value" so I can read them, even if they don't make it to the front page.
Consider, I can train a Bayesian Filter with the page text of many submissions, and get that to predict what I'm likely to find "of value." But that means I don't see what the community might have found interesting but would be outside my core interests. These, too, are "of value" because they stretch me. I can't just train the filter with what makes the front page, because the evidence is that many things that "should" (by some definition) don't, and that would damage the training.
So it's complicated. I'm trying to find ways to improve the community and help me get more out of it (obviously) with less effort. I'm trying to help, but the hassle I get is just encouraging me not to make these observations out loud.
Based on this, your profile, and the rest of the comments in this thread I would suggest that whatever it is you're doing is vastly more effort than you're going to get back in added value.
Well in a very real way the system has to intentionally obfuscate the 'way to the front page' because being on the front page is so valuable, thus a target for manipulation.
What I'm saying is that as soon as you find a fool proof way to submit something and have it show up on the front page, pg will 'fix' it so that you can't do that in the future just like linking the discussion in a blog post was 'fixed'.
I typically read the site from an RSS feed, which means I see everything that is submitted that makes it to the rss feed, regardless of whether it is on the 'new' page or has fallen off. I don't know what percentage of folks do that. There are also 'super powers' for some users but those are for the standard sorts of things (like make sure a YC company looking for people gets to the front page for a while).
Can you say more about what "improving the system" would entail?
I'm not looking for a guaranteed way to get to the front page. I'd guess that most of the things that don't make it, deserve not to make it, in the sense that while they might be interesting, even if most HN people saw it, it wouldn't get many votes.
My concern is that things that are clearly of interest (in the sense that they do eventually do get the upvotes in a subsequent submission) sometimes don't get noticed and don't get the upvotes they deserve (by some definition).
Or something.
> I typically read the site from an RSS feed, which means
> I see everything that is submitted that makes it to the
> rss feed, ...
Do you apply some sort of filtering, or do you literally scan everything by eye?
> Can you say more about what "improving the system"
> would entail?
My ideas are very badly formed at the moment, and I'd rather not try to put them in written form in an open forum. I wouldn't care if people stole them, I'd care more that they would look pretty stupid, because I couldn't explain them well enough. Yet.
I think the title doesn't describe properly this great article. I'm afraid it might be turning away readers who would otherwise really enjoy the coolness of this read!
The title can be read as "How to engineer pornography", at least that's how I read it at first. OP might want to edit it to remove any ambiguity.
> The title can be read as "How to engineer pornography", at least that's how I read it at first. OP might want to edit it to remove any ambiguity.
I read an AMA on Reddit at one point from a guy who worked as a server engineer on some large porn website/network. The questions were mostly about engineering, but the answers were fascinating - when you think about it, porn networks have to face the same scaling issues as many startups, and they have some unique challenges (and also advantages) that other markets don't.
I was secretly hoping this post would be something along those lines. Interesting nevertheless, but not what I was expecting!
Same here, I thought it would be about load handling, or maybe something about tricks they might have used on scene. Nevertheless, I also think this article is great! But if I were at work, maybe I would think twice before opening a link that might be NSFW. Or I can picture some people might not be interested in anything porn related, for many reasons.
When it was originally submitted (http://news.ycombinator.com/item?id=193112), it had the title How to repair a 230KV, 10 mile long coaxial power cable. But I suppose that that informative title would now be pedantically edited to the one you see here. As well, without the link-bait version it might only have blinked through the front page in 30 seconds.
Actually that's exactly what I thought it was, and I avoided it all day. I figured it was something about getting the lighting and camera setups right, or figuring out what sells best.
It wasn't until I saw it on the EngineeringPorn subreddit that I realized what it really was and read it. Now I'm glad I did.
Something like "Engineering Porn: Fixing 230kV Underground Cables" would have done it.
Having played with some back in school, it's this gnarly paper that is super stiff, near invulnerable (to hand attempts at tearing and cutting), and really really good at giving paper cuts. It's also somewhat fire retardant, if I remember correctly.
So, it's not like the cable was wrapped in Christmas paper or something.
You don't need a voting disclaimer to talk about a color scheme, that just wastes words.
What exactly hurts your eyes? Are you fine with light gray on black? I can sort of understand disliking the amount of green, but if it's just because of the black background then you probably having lighting issues in your setup.
It's insanely high-contrast with a relatively light (thin) typeface and light-on-dark. While I fear the idea of having that neon green as the background instead as I may start glowing, having a slightly heavier font or a not-so-extreme green would have been a lot easier to read. Even when I had a green-on-black terminal it wasn't a problem, I believe because the font weight was a bit heavier and physically deciphering the characters was less taxing.
Seconded. Neon green on black is very, very jarring to read. White on black causes strain for large amounts of text. (There's a reason no news sites use white on black.) Lowering the contrast is bad enough, but the green clashes with the black and is downright painful.
Showing my age, but I worked for years in a dark room with a green screen terminal. I've long since made a habit of setting my terminals (regardless of OS) to exactly the same bright green on black. I do prefer the font bolded though. When I first started (rather shortly after--few years) CRT replacements became available for my favorite terminals. So if I wanted I could use either bright blue on black or bright red. Both surprisingly useful in darkened rooms!
> The thumper sends mondo-amp pulses into one end of the cable. The electromotive force tends to cause physical displacement of the conductors which you can hear from the street level.
That sounds amazing and terrifying, sort of like the engineering equivalent of the old soviet dentists' belief that they have to poke cavities and judge their location and severity by how badly the patient reacts.
We had a power short at $work this summer, with MUCH smaller wiring. They brought in an Astro van filled will equipment to do the same fault finding. Standing above the fault, as the Xcel lineman told me to, I could feel the ground move. It was an interesting experience.
Am I the only person who was disappointed that this article was not about "Taking an engineering approach to pornography"?
Wouldn't it be interesting to hear someone's lessons learned from using Lean Startup and A/B testing when entering the porn industry to discover best practices, instead of just using "Tried and True" methods?
Is porn an industry ripe for disruption?
I wonder if anyone has applied to YC with a pornography startup.
> That's where the LN-2 comes in. An elegant solution if you ask me.
It's quite a classic solution for subway construction and restoration in the deep areas. In certain conditions, when tunnels get flooded with quicksand, liquid nitrogen can be used to isolate them.
Anything other than #00ff00 on #000000 is apparently just not 1337 enough. It's more important than people actually being able to read the content on your site.
Like most failures, this is a systems failure. Someone engineered the hell out of that cable. But they neglected to realize that it would be drawn through a steel pipe.
"So, what went wrong? Varying load conditions in the three legs of the 3-phase circuit caused tremendously strong and dynamic magnetic field changes. The electromagnetic forces between the three conductors and the steel pipe (gack!) cause the conduit to wiggle around inside the pipe."
The other lesson is that you shouldn't hyper-optimize locally, and instead design for maintainability. I'm not sure what they were thinking when laying a cable that requires experts to be flown in from the east coast to repair. The simplest mechanisms are the ones that are the most easily repaired. The entire article goes on in great length about how awe-inspiring the engineering of this cable is, whereas I just see a bunch of complexity that probably didn't need to be there. The 118 layers of paper tape, and the oil pumps, and so forth. Surely there was a simpler solution. I'm sure after this failure and the ones on the east coast, they are not still laying cables like this.