Engineering Pornography (2002)

http://www.jwz.org/blog/2002/11/engineering-pornography/

by wallflower • 14 years ago

235 77 14 years ago

> 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.

langseth• 14 years ago

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.

ajb• 14 years ago

"They learned the hard way that you simply don't reverse the pumps lest you get the Golden Bear [mineral oil] equivalent of water hammer".

Ouch. It must have been 'fun' finding that out. Another example of extreme water hammer: http://www.davros.org/misc/ambridge.html

AYBABTME3• 14 years ago

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.

chimeracoder• 14 years ago

> 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!

AYBABTME3• 14 years ago

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.

mhb3• 14 years ago

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.

AYBABTME3• 14 years ago

The last few hours have proven me wrong, the possibly-misleading title has kept the article on the front page so far.

Interesting.

specialist• 14 years ago

True. Worried the OP might be NSFW, I scanned the HN comments first.

MBCook• 14 years ago

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.

e40• 14 years ago

I know I'll get downvoted for this, but I find jwz's site ridiculously hard to read because of the color scheme. It really hurts my eyes.

Dylan16807• 14 years ago

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.

benesch• 14 years ago

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.

Firehed• 14 years ago

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.

hsmyers• 14 years ago

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!

gyardley• 14 years ago

The Readability browser extension is awesome for cases like this. I use it all the time.

raldi• 14 years ago

I downvoted your comment, but only because of its first seven words.

drcube• 14 years ago

Funny enough, I really like it. What hurts my eyes are sites that are predominately blindingly white.

chubot• 14 years ago

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.

mikeash• 14 years ago

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.

pixl97• 14 years ago

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

http://www.fujikura.com.sg/hv_xlpe.htm

At the the maximum voltage over XLPE was 110kV.

Sticking 2 of these cables side by side would have other interesting effects.

http://www.emfs.info/Sources+of+EMFs/Underground/multiple.ht...

It appears oil and paper systems are still used, but I don't think they use the high pressure oil system like the one in the paper.

http://www.hitachi-cable.com/about/publish/review/__icsFiles...

elteto2• 14 years ago

There is no "simple mechanism" to transport 600-800 amps across 10 miles. That amount of current alone is just mind blowing.

rdl2• 14 years ago

I think this would depend on voltage. Transporting 800 amps 10 miles is done all the time -- a normal house has 100-200A service.

The issue is that this is 230 KV, vs. 230V.

79522• 14 years ago

In London they are digging a 32km tunnel using TBM's to carry 400kV AC lines.

pavel_lishin2• 14 years ago

> e.g. civil engineers know how to build a bridge and deliver it on time.

Tell that to the Texas Department of Transportation, where any given highway project will typically run over time and budget.

angersock2• 14 years ago

To be fair, all those Aggies have to end up somewhere. :)

205guy• 14 years ago

I believe that is a feature and not a bug. At least for the contractors and their friends in governmnet.

purephase• 14 years ago

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.

sbierwagen• 14 years ago

  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.

http://www.howtospotapsychopath.com/2010/03/10/today-on-surf...

  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?"

pestaa• 14 years ago

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.

jrockway• 14 years ago

"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?"

This is actually a good idea.

arjunb• 14 years ago

"I don't see why every web site makes you create a new account. Why not log into everything with my facebook account?"

Actually for many web sites this is a pretty good idea too.

mhb3• 14 years ago

Chesterton's thoughts on those ready to reform that about which they know little:

http://stuartbuck.blogspot.com/2004/05/chesterton_14.html

greenyoda2• 14 years ago

This is sort of like the electrical engineering equivalent of the Tacoma Narrows Bridge collapse:

https://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940)#C...

greenyoda2• 14 years ago

"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.

giardini• 14 years ago

"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.

ZeroGravitas• 14 years ago

"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:

https://www.youtube.com/watch?v=9tzga6qAaBA&feature=yout...

imgabe• 14 years ago

> 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.

ColinWright7• 14 years ago

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.

ChuckMcM2• 14 years ago

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 what are you saying?

ColinWright7• 14 years ago

    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.

mhb3• 14 years ago

You may also be intrigued by the comments from when it was posted 1677 days ago:

http://news.ycombinator.com/item?id=193112

ColinWright7• 14 years ago

Well found - thanks.

scott_s2• 14 years ago

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.)

ColinWright7• 14 years ago

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.

Thanks.

hooande• 14 years ago

Is this the study you had in mind? http://www.princeton.edu/~mjs3/salganik_dodds_watts06_full.p...

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.

duaneb• 14 years ago

A sample size of 2 is much too small to inductively reason.

bashzor• 14 years ago

IT'S GREEN :|

http://www.readability.com/articles/dcsyvhkh

dbbolton• 14 years ago

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.

kiallmacinnes• 14 years ago

    I have to reset my difficulty meter for engineering problems now.

I know how that commenter feels!

scheff• 14 years ago

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.

rootbear• 14 years ago

Wow, I remember reading that back when it happened. Great story of some amazing engineering.

angersock2• 14 years ago

In case anybody is confused about the "paper tape", transformer paper is likely what they're referring to ( http://en.wikipedia.org/wiki/Electrical_insulation_paper ).

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.

gvb• 14 years ago

http://www.youtube.com/watch?v=hIkNY5xjy5k Youtube video of a 500KV substation breaker popping - one of the three legs did not quench properly. Impressive!

jason_adleberg• 14 years ago

spoiler: there is no actual pornography in this link. just sayin

shmerl• 14 years ago

> 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.

bitdiddle• 14 years ago

Love the symbolics.com address

Engineering Pornography (2002)

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