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Another English/Metric "Spacecraft" Problem

SuperDry writes "There's been another spacecraft failure that's been attributed to an English/Metric units problem, this time at Tokyo Disneyland's Space Mountain. An axle broke on a "spacecraft" (a.k.a. roller coaster train) mid-ride, causing it to derail (nobody was hurt). The final investigation report has been released, and the root cause has been determined to be a part being the wrong size due to a conversion of the master plans in 1995 from English units to Metric units. In 2002, new axles were mistakenly ordered using the pre-1995 English specifications instead of the current Metric specifications. Apparently size does matter, even if it's only a 0.86mm difference."

36 of 748 comments (clear)

  1. Proble? by waitigetit · · Score: 5, Funny

    It's more like an English spelling problem, no?

    --
    I could care less, but not without a lobotomy
  2. Disney by abh · · Score: 5, Funny

    How come everything Disney does ends up so Mickey Mouse?

  3. Who's at fault here, really? by ObviousGuy · · Score: 4, Funny

    The Japanese who, like the rest of the modern world, switched to metric years ago?

    Or the American designers who couldn't even do simple multiplication in order to convert from English to Metric?

    --
    I have been pwned because my /. password was too easy to guess.
    1. Re:Who's at fault here, really? by flewp · · Score: 4, Informative

      Well, if you RTFA, you'd see that the parts were ordered using older specifications, and the parts delivered were consistent with the designs that were ordered. The problem was they put it in an order for the wrong size.

      Consequently, two different drawings existed within our company after the changes were made and the old drawing showing the 44.14 mm diameter was used to order (in August 2002) the axles that were delivered in October 2002.

      --
      WWJD.... for a Klondike bar?
    2. Re:Who's at fault here, really? by agentZ · · Score: 4, Interesting

      So in other words it wasn't a metric/inches conversion problem, but rather just using the old blueprints instead of the current one?

    3. Re:Who's at fault here, really? by Stalus · · Score: 4, Informative

      The .86 error was because someone decided that they wanted round numbers, so when they changed the spec, they decided to round up. Well, in the process they forgot to throw out the old documentation. So, they ordered the correctly sized part for the old spec and got it wrong.

      Probably a good example for software engineering class. "See, changing the specification, once released, may result in bodily harm!"

    4. Re:Who's at fault here, really? by Rhubarb+Crumble · · Score: 5, Insightful
      Hey, I like the metric system. I really do. But sticking to the english system has never caused an aircraft to run out of fuel at altitude, a roller coaster to break, or a spacecraft to crash. The zeal to enforce metric conversion, however, has caused all of those things.

      Hey, I like the imperial/english/mediaeval/whatever system. I really do. But sticking to the metric system has never caused an aircraft to run out of fuel at altitude, a roller coaster to break, or a spacecraft to crash. The zeal to make specifications understandable to people who think in terms of the size of kings' thumbs and the area of land that can be ploughed by an ox in a morning, however, has caused all of those things.

      The simplest argument in favour of the metric system is that it's base-10... (or base-10^3 if you want to be picky...) Of course once all our civilisation is outsourced to India and China I guess we'd better get used to counting in 10^4 or 10^5... (wans and lakhs)

    5. Re:Who's at fault here, really? by hoofie · · Score: 5, Interesting

      Actually you are wrong !!!

      In 1983 an Air Canada flight ran out of fuel mid-flight. Disaster was averted due to a long-enough disused runway being available.

      Its now know as the "Gimli Glider" named after the abandoned air-force base where it landed. It was luck that one of the pilots was a glider pilot. Apart from the complete-cock up, it showed some fantastic flying and emergency management.

  4. Gotta ask... by thatguywhoiam · · Score: 4, Funny
    Another English/Metric "Spacecraft" Proble

    I'm Canadian, so I have to assume that 'proble' is the... imperial spelling... of problem?

    "I get five rods to the hog's head!"

    --
    If Jesus wants me it knows where to find me.
  5. See!! by Anonymous Coward · · Score: 4, Funny

    We need a one world government with one way of doing things! How many more people have to die because we have to hang on to old ways of doing things? Stop this madness now! Surrender your nationalist ideals. Borders exist in the minds of dimwitted politicians. Borders can't be see from space. We must unite and work together to advance mankind.

    Support the New World Order now!

  6. Miscommunication by Anonymous Coward · · Score: 5, Informative

    From the Article:

    In September 1995, the design specifications for the size of the axle bearing for Space Mountain vehicles was changed from inches to the metric scale. Accordingly, the axle diameter was also changed, in this case from 44.14 mm to 45.00 mm. However, appropriate action to revise and maintain the design drawings was neglected. Consequently, two different drawings existed within our company after the changes were made and the old drawing showing the 44.14 mm diameter was used to order (in August 2002) the axles that were delivered in October 2002.

    They actually changed the specs. The conversions were all done correctly but they failed to update everyone.

  7. English units? by Anonymous Coward · · Score: 5, Insightful

    I don't know about you, but us English call the measurement system the Imperial system. Isn't the American version slightly different, in respect to fluid units, etc?

    1. Re:English units? by Anonymous Coward · · Score: 4, Informative

      Isn't the American version slightly different, in respect to fluid units, etc?

      Only with respect to fluid units. And the base unit, the ounce, is the same. Measurements based on the pint are different: a US pint is 16oz an Imperial pint (the only legal Imperial measure left in the UK!!!!) is 20oz. A gallon is 8 pints, a cup is a half-pint, but a US gallon or cup is 4/5 of the British counterpart.

      I thought the Brits moved glacially since the UK has been metric since 1971... officially (except for beers. I don't know how long road measure will remain Imperial). Then I found out that the US has been co-metric since Ben Franklin (http://www.nist.gov).

      No system of measure is inherently better or worse than another. But, when everybody you trade with uses a different system, it might be time to reconsider (not that the UK should adopt the Euro....)

    2. Re:English units? by Hogwash+McFly · · Score: 4, Funny

      The system is fascinated with 1/16ths and 1/32s which gets really hard to work with

      Your Geek Pass has been revoked. You have one hour to clear your desk and leave the building. Thank you for your co-operation.

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    3. Re:English units? by sketerpot · · Score: 4, Insightful
      Hear hear. I find Imperial units extremely painful to do conversions with, so I propose that we go to the much easier Metric system! It's all for the better! You can do conversions in your head! Complicated conversions! We will CRUSH OUR ENEMIES WITH THE METRIC SYSTEM!

      Besides this rather geeky calculation, people who use and defend the use of the imperial system don't know how to use it! I was talking to someone about DSL, and I said something like, "even if you're 15000 feet from the CO, and you're much farther, performance would suck." and she had no idea how far that is in miles (it's a little less than 3, for our metrified friends).

      That's exactly what I'm talking about. I live in the US, and I couldn't for the life of me do that conversion without the aid of a reference and a calculator. With metric, it would be so easy that I could just say it in meters or kilometers without missing a beat.

  8. Imperial, not English... by arafel · · Score: 4, Insightful

    Why do you call them 'English' units, when everyone else knows them as Imperial units? :-) We stopped using most of them some time ago.

    1. Re:Imperial, not English... by deitel99 · · Score: 5, Funny

      For example, the inch is now _defined_ as 2.54 cm, it has nothing to do with some king's thumb or anything.

      Personally I think 2.54cm is pretty arbitrary. Then again, cm are based on a fraction of a wavelength of a certain coloured light, which is, yet again, arbitrary.

      The first attempts for standardising the inch were many hundreds of years ago, since it's so vital to have correct measurements for trade. Despite what most posts here seem to think, the Imperial Inch does not change every time the English monarch does.

  9. How many Rods to the Hogshead?... by Anonymous Coward · · Score: 5, Funny

    It wasn't mentioned in the article, but for my own reference, I'm wondering how many Rods to the Hogshead this ride gets?
    Or if that info. isn't available, how many stone per fortnight this ride has in lifting capacity.

    TDz.

    1. Re:How many Rods to the Hogshead?... by flewp · · Score: 4, Funny

      how many stone per fortnight this ride has in lifting capacity.

      That depends if the ride is European or African.

      --
      WWJD.... for a Klondike bar?
  10. 0.86mm? That's a HUGE difference! by cnelzie · · Score: 5, Informative

    In the automotive industry being off by that 'gigantic' mile of a discrepancy can be the difference between an entirely safe system or a potentially dangerous event just waiting to happen.

    Anything from rubbing away the lining of important wires or hoses, different stress locations resulting in tear apart pieces that shouldn't be tear apart can happen by being off by that much...

    0.86mm might at well be 3 feet off. A part that comes out that far off is nothing but scrap material. (Well at least in our area of automotive work.)

    --
    If you ignore the other uses of a tool, does that make the tool less useful, or you less useful?
    1. Re:0.86mm? That's a HUGE difference! by Gordonjcp · · Score: 4, Informative

      Well, 1mm of play in something like a trailer coupling probably won't make a difference. 1mm of play in a wheel bearing would make the wheel and hub wobble appreciably (on a car it would make it very unpleasant to drive), and that same 1mm in an engine's main bearings would cause the engine to hammer itself to bits in minutes.

    2. Re:0.86mm? That's a HUGE difference! by zulux · · Score: 4, Funny



      Lemmeee tell 'ya....

      Here at Hyundai - .86mm is barely noticible. It just means you have to push harder to get the part to fit.

      Our cars can take it!

      --

      Moneyed corporations, non-working 'poor' and criminal prisoners are turning productive citizens into tax-slaves.

  11. English/Metric by Ianoo · · Score: 4, Informative

    Please don't say English/Metric units. The UK is effectively metric now, all schoolchildren are only taught metric units and everything has to be priced in metric units. I don't even have intutitions about how long feet are or how heavy a stone is. Pretty much everyone under the age of 25 only deals with litres, metres and kilograms. The only exception is vehicle speed, which is still measured in mph (and hence all our road signs are in mph). You won't, however, catch any British Engineers or scientists using Imperial units.

    Better ways to describe them would be "Imperial" (what we call them), "American" or "Archiac". I think it's about time the US caught up with the rest of the world and ditched these stupid and difficult-to-remember units once and for all.

    1. Re:English/Metric by CaptainAlbert · · Score: 4, Informative

      The UK is effectively metric now, all schoolchildren are only taught metric units

      Except by their parents, who will teach them the Imperial units anyway.

      My experience is at odds with this assertion that all the youngsters talk metric. Although when at work, just about everything is metric (except if it's American :)), everyone I know (including those younger than me) measures their weight in stones and pounds, and their height in feet and inches. And, more importantly, their beer in pints!

      I much prefer units I can relate to, personally. If the metric system has given us nothing else (which it hasn't), at least we have the Centigrade scale. I'm all for keeping the old-fashioned units alive, but really! Who thought water freezing at 32 and boiling at 212 was a sensible scale?

      I know the significance of 0F as being the lowest acheivable temperature where salted water remains liquid, but can anyone explain the rest? It still completely baffles me!

      P.S. Slashdot ate my ° markup, sorry!

      --
      These sigs are more interesting tha
  12. The horror by netfool · · Score: 4, Funny

    >Apparently size does matter, even if it's only a 0.86mm difference. At this very moment there are hundreds of geeks around the world trying to think of a great punchline for this.

    --
    Left 4 Dead Gaming Group - http://www.l4dgg.com
  13. It had nothing to do with the conversion directly. by bluprint · · Score: 5, Informative

    If you had read the article, you would know that the problem was, while converting to metric, they also changed the specification of the axle size, but didn't record the new axle size correctly. So, the problem really had nothing to do with any mathematical error, just an error in incorrect documentation.

    --
    A modern day witchhunt.
  14. The US needs to catch up by Listen+Up · · Score: 5, Insightful

    The US needs to catch up to the rest of the world. The entire world uses Metric people. And it makes an infinite amount more sense to use Metric than the US system. If we don't, trade will continue to suffer as well as accidents such as this one.

  15. The Japanese did the conversion. by mookoz · · Score: 5, Informative
    Bob Gurr (ex-Disney Imagineer) tells the story of the Tokyo Disneyland conversion here:

    http://www.laughingplace.com/News-ID108300.asp

    Great set of columns, by the way. I've always been a fan of how some of the disney technology was invented and implemented.

  16. Just use google calc by beej · · Score: 5, Funny
    10 meters = 98.4251969 hands

    HAHAHAH! No one uses hands anymore to measure distance! How ARCANE!

    We use feet.

  17. About time America left the stone age by GileadGreene · · Score: 5, Interesting
    Sigh. When is America going to ditch its archaic measurement system and use the same standard as everyone else? I work in the space industry, and I see this idiocy going on all the time: half the team works in metric, the other half in english. Most of the time everyone manages to keep it straight. But every now and then, a mistake happens. Scientists all use metric. Most engineers are trained in metric. Let's just switch to metric for everything and be done with it.

    A side note: in New Zealand (and possibly other Commonwealth countries - I haven't checked) they don't even refer to "English units". Their term is "Imperial units". Which tells you how long it's been since they made the switch...

  18. America versus the rest by Anonymous Coward · · Score: 5, Interesting

    Some things that would be nice to standardize (but will probably not happen in my lifetime)

    - imperial - metric
    - Letter paper - A4
    - Fahrenheit - Celcius
    - AM/PM - 24 hr notation
    - month/day/year - day/month/year

    Anything I left out?

  19. The right term is "U. S. Customary" by dpbsmith · · Score: 4, Informative

    (And the right term for "metric" is "SI").

    SI units are legal in the United States and have been for a very long time. The inch was set at precisely 25.4 mm _by definition_ in July 1959.

    The additional units, such as inches, miles, quarts, pounds, etc. which I believe are all legally defined by reference to SI units, are officially and properly referred to as "U. S. Customary" units. They have, of course, a strong historical connection to English units.

    Unofficially, "Metric" and "English" are the U. S. customary designations for "SI" and "U. S. Customary."

  20. Re:If the U.S. hates the french so much by Progman3K · · Score: 4, Insightful

    If the U.S. hates the french so much, they should dynamite the Statue of Liberty, because that was a gift from the french to the U.S.

    It would serve the french and the americans right!

    See how stupid all this french or american bashing is?

    Grow up, people.

    --
    I don't know the meaning of the word 'don't' - J
  21. Fahrenheit's reasons by medscaper · · Score: 4, Informative
    The only reason why the Fahrenheit scale used a non-zero value for the freezing point of water was that people of the time didn't have a strong grasp of the concept of negative numbers.

    Bzzzzt. Thanks for playing!

    From boson.physics.sc.edu :

    At the beginning of the eighteenth century, the Danish astronomer Ole Roemer (famous for making the first measurements that showed that the velocity of light is finite) devised a temperature scale of his own for use with the alcohol-in-glass thermometers that he constructed. His thermometers attracted the attention of Gabriel Fahrenheit (1686-1736), a manufacturer of meteorological instruments in the Netherlands. In 1708 Fahrenheit traveled to Copenhagen to meet Roemer and see his thermometers, which were based on two reference points. For one reference Roemer used a mixture of ice, water, and salt to reach the lowest temperatures then attainable in the laboratory, which he called zero. His other reference was the boiling point of water, which he arbitrarily designated as 60 degrees.

    Fahrenheit returned home to make thermometers like Roemer's. In 1714 he overcame technical difficulties with alcohol thermometers by substituting mercury as the expanding liquid. The use of mercury extended the range of temperature measurements from well below Roemer's zero to well above the boiling point of water. Furthermore, mercury expanded and contracted more uniformly than the other liquids then in use. As a result, Fahrenheit could mark his mercury thermometers more accurately and with finer divisions.

    By 1724 Fahrenheit had adopted a new scale, similar to Roemer's but with much finer divisions. For the zero point he chose the same reference as Roemer. However, since his thermometer was intended for meteorological observations, he wanted a second reference point that would be nearer the maximum observed temperature for weather. He chose the normal temperature of the human body as the upper reference point, which he called 96. Fahrenheit gave no reason for his choice of 96, but it may have been due to his desire for a finer scale and because 96 is evenly divisible by 2, 3, 4, 8, and 12.

    Why didn't Fahrenheit choose the freezing point of water for his zero reference, as Newton had done before him and as Celsius did later on? Perhaps Fahrenheit was influenced by Roemer, or he may have wanted to avoid the inconvenience of repeatedly using negative temperatures during winter. Also, in the early 1700s it was widely believed that water did not always freeze at the same temperature. Soon, using his newly calibrated thermometers, Fahrenheit learned that water always froze at 32 on his scale. He immediately added this third reference point to his instruments.

    --
    Any sufficiently well-organized Government is indistinguishable from bullshit.
  22. Re:The source of the problem by saforrest · · Score: 4, Funny

    Is that the metric system is flawed. It is defined in terms of the size of 18th century railroad tie sizes, which is totally arbitrary.

    Mmm-hmm. So, clearly, defining length in terms of the feet of a 1200-year old dead Frankish king is a better choice?

  23. Blah blah US economy blah blah by Imperator · · Score: 4, Insightful

    Don't give me that crap about how much better the US economy performs than the EU. The median standard of living in the EU is higher than in the US. The US economy is great at producing wealth at the top, but conservative Americans have an aversion to using the economy to solve social problems ("communism! class war!"). I think this is a major reason why Europeans view the US as "backwards". Yes, both the US and the EU have economies that have solved the problems of food, shelter, and medicine. But the US has not seen to distributing those solutions to the people.

    Many Americans have an ingrained sense that the only job of the economy is to grow. Things like social nets and environmental protections interfere with the ability of the (total) economy to grow at the fastest rate possible, so they must be inherently bad. This is the unifying economic philosophy of the conservative Republicans: government itself is inherently bad precisely because it siphons money (taxes) away from investment and consumption. If you believe in Reaganomics ("a rising tide lifts all boats") this makes some sense. But in the real world, it leads to a morally bankrupt society obsessed with money.

    </rant>

    So in conclusion, there are 36 inches in a yard.

    --

    Gates' Law: Every 18 months, the speed of software halves.