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Spain builds submarine 70 tons too heavy by putting a decimal in the wrong place

o.canada.com

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Re: Spain builds submarine 70 tons too heavy by putting a decimal in the wrong place

#31

Post by priv_acy »

In the aerospace business there is a guy known as the Mass Properties Engineer who gets to rule the project with an iron fist. He is responsible for knowing the estimated, calculated or measured weight of every part on the spacecraft from concept through to launch. It's not a very fun job, but it's very important. Some people actually made careers out of it. You simply cannot get this stuff wrong and not pay dearly for it later. There are reviews, arguments, dealings, and handwringing over all of this.

Now, I have no idea if the Spanish sub business runs anything like that, but it surprises me that it apparently doesn't or didn't in this case. It's not like you just let some engineer in the corner calculate the weight and then go build it. This is a systemic fuckup, not a shifted decimal point.

Re: Spain builds submarine 70 tons too heavy by putting a decimal in the wrong place

#32

Post by damoncali »

jsolson wrote: post #17
ars wrote: post #11

Earlier quoted context omitted.

With the advent of computers and programming languages that only use decimal points, I wonder how long countries will hold out and continue using decimal commas. I would not be in the slightest surprised to see that engineering would standardize 100% on decimal points (even if the public used commas), just like how in the US engineering (except houses) uses metric, even though the public uses imperial. (Also, presuma…

> US engineering (except houses) uses metric, even though the public uses imperial. I don't know that I'd make this claim, in general. Everything from bikes to American cars can still be found with imperial nuts and bolts. Even the robotics work I did in school was mostly in imperial units due to the greater availability of, for example, 1/4" 6061 Aluminum stock. People will stick to whatever system is most convenien…

When I worked at NASA, nothing was metric unless it came from overseas. Everything we built was imperial. I preferred it for a few reasons, one of which was that it's harder to make a decimal point error with imperial units.

Re: Spain builds submarine 70 tons too heavy by putting a decimal in the wrong place

#33

Post by sliverstorm »

dm2 wrote: post #22
muzz wrote: post #14

Earlier quoted context omitted.

no, that's not the cost to fix the $14M is just for "an assessment of the problem with the S-80 submarine program and the scope of the work that would be required to correct it"

ok, so $14M + parts and labor

I wonder what book time is?

Re: Spain builds submarine 70 tons too heavy by putting a decimal in the wrong place

#34

Post by damoncali »

akiselev wrote: post #26
fosap wrote: post #20

Earlier quoted context omitted.

I'm almost 100% sure engineers use the SI system. (unlike physicist that use a system that seems to be fitting). And the SI system says that 100.000 and 100,000 are the same. The Si system only uses space to group numbers like 12 343,123 12 for twelf thousand and so on.

My thought was that anything that used the decimal comma could be confusing when dealing with vectors. However, I wouldn't go so far as to say they use SI across the board. I know aerospace engineering in the US can often switch between imperial and metric depending on which contractors work on the project (this resulted in a mission failure on at least one occassion: http://en.wikipedia.org/wiki/Mars_Climate_Orbiter…

You'd be right. At NASA we could use whatever we wanted. There was no directive to do one thing or another (at least not one I ever knew about) - only the conventions that allowed you could communicate with your peers. Much of the technology we used had evolved over decades. Changing it to metric would have been insane.

An interesting line from that wikipedia article: This error has since been known as the "metric mixup" and has been carefully avoided in all missions since by NASA.

This is categorically not true, as I worked before and after that, and it had zero impact on the units we used or how we checked them. Most of the time nothing was metric, so it didn't matter.

Re: Spain builds submarine 70 tons too heavy by putting a decimal in the wrong place

#35

Post by teamonkey »

Jare wrote: post #16
ars wrote: post #11

Earlier quoted context omitted.

With the advent of computers and programming languages that only use decimal points, I wonder how long countries will hold out and continue using decimal commas. I would not be in the slightest surprised to see that engineering would standardize 100% on decimal points (even if the public used commas), just like how in the US engineering (except houses) uses metric, even though the public uses imperial. (Also, presuma…

Decimal points vs decimal commas is a common problem here (and other countries with similar locale details) with software, when exporting numbers in text format to be processed by other software. Over the years I have had to correct for this in 3DSMax and Excel scripts. Very annoying.

It doesn't matter which format of CSV file you choose, or what settings you use, what Excel actually saves will be different depending on the language profile of the individual user. Not useful in a bilingual office, especially if you want a script to parse that CSV.

My simple hack was to create a macro button that saves to CSV, because the macro function ignores the language settings (probably a bug?) and always saves in the English format.

Re: Spain builds submarine 70 tons too heavy by putting a decimal in the wrong place

#37

Post by gmrple »

priv_acy wrote: post #31

In the aerospace business there is a guy known as the Mass Properties Engineer who gets to rule the project with an iron fist. He is responsible for knowing the estimated, calculated or measured weight of every part on the spacecraft from concept through to launch. It's not a very fun job, but it's very important. Some people actually made careers out of it. You simply cannot get this stuff wrong and not pay dearly f…

My electrical engineering professors were constantly trying to ingrain in us the tendency to estimate the solutions to problems long before solving them. Why? because if you know the ball park solution you'll be able to catch gross errors before they happen. Thus you will be less likely to pull a Homer Simpson at the power plant or end up transmitting too much power from your antenna. I'm thankful to be in an industry where catastrophic failure does not have such harmful results.

Re: Spain builds submarine 70 tons too heavy by putting a decimal in the wrong place

#38

Post by Anechoic »

ars wrote: post #11
tzs wrote: post #4

> And a former Spanish official says the problem can be traced to a miscalculation — someone apparently put a decimal point in the wrong place Sloppy reporting. Spain uses a decimal comma.

With the advent of computers and programming languages that only use decimal points, I wonder how long countries will hold out and continue using decimal commas. I would not be in the slightest surprised to see that engineering would standardize 100% on decimal points (even if the public used commas), just like how in the US engineering (except houses) uses metric, even though the public uses imperial. (Also, presuma…

just like how in the US engineering (except houses) uses metric

Copying from a previous comment: This isn't true in my experience. Of course my experience certainly isn't comprehensive, but in my work I interact with a lot of US fields (environmental, manufacturing, civil & mechanical engineering, etc) and I almost never see metric units. The Federal Highway Administration tried to encourage state DOT's to go metric for design and engineering work back in the late 90's but they eventually gave up. If you ever worked on an American car, you still find a mix of metric and Imperial bolt sizes! About the only field where I found that metric units are used extensively is wind energy.

Even my mechanical engineering PE exam used Imperial units exclusively (pounds force vs pounds-mass... sigh)

I imagine that your statement is probably most true for the military though.

Re: Spain builds submarine 70 tons too heavy by putting a decimal in the wrong place

#40

Post by lostlogin »

derekp7 wrote: post #27
bigiain wrote: post #25

Earlier quoted context omitted.

We've been "fully metric" here in Australia since the early '70's - I still find it amusing when seeing things like the building industries "standard sizing", where everything comes in 900mm increments and lumber all comes in sizes like "50 by 100mm nominal". Everything is still built out of 3, 6, and 12 foot two-by-fours and 3 by 6 foot 1/2 ply sheet - all labeled with metric dimensions of varying clarity.

Same with the Mexican Coke bottles that we get in some US stores (Mexican Coke is made with real sugar). It is a 12 ounce bottle, labeled as 355 ml.

We get 355ml cans here in New Zealand - I had no idea it related to anything at all. Thank you.
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