Another English/Metric "Spacecraft" Problem 748
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."
Proble? (Score:5, Funny)
Have You SEEN The Size Of A Millimeter? (Score:3, Insightful)
A 1mm gap/variance leaves bearings, seals, valves, and gears unusable in most situations.
Re:margin of error? (Score:3, Insightful)
I was getting a haircut the other day. I didn't want a whole inch off. So I asked for a centimeter taken off. The stylist had to ask me how long a centimeter was.
Disney (Score:5, Funny)
Who's at fault here, really? (Score:4, Funny)
Or the American designers who couldn't even do simple multiplication in order to convert from English to Metric?
Re:Who's at fault here, really? (Score:2)
Re:Who's at fault here, really? (Score:3, Informative)
Re:Who's at fault here, really? (Score:2, Insightful)
Re:Who's at fault here, really? (Score:5, 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!"
Re:Who's at fault here, really? (Score:5, Informative)
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.
Re:Who's at fault here, really? (Score:5, Interesting)
It had nothing to do with the conversion directly. (Score:5, Informative)
The Japanese did the conversion. (Score:5, Informative)
http://www.laughingplace.com/News-ID108300.asp [laughingplace.com]
Great set of columns, by the way. I've always been a fan of how some of the disney technology was invented and implemented.
Re:Who's at fault here, really? (Score:5, Insightful)
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)
Re:Who's at fault here, really? (Score:5, Interesting)
In 1983 an Air Canada flight ran out of fuel [mines.edu] 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.
Re:Who's at fault here, really? (Score:3, Informative)
Gotta ask... (Score:5, Funny)
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!"
See!! (Score:4, Funny)
Support the New World Order now!
Re:See!! (Score:3, Funny)
Kodos or Kang?
Re:See!! (Score:2, Informative)
Miscommunication (Score:5, Informative)
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.
English units? (Score:5, Insightful)
Re:English units? (Score:4, Informative)
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....)
Re:English units? (Score:3, Interesting)
Until they pry miles and pints from our cold, dead hands.
Seriously, I was never taught any imperial measures, and had to work out a lot of conversions myself, particularly as we have a hybrid system in place that mixes different units according to application. I'm long since out of the school system, but I was born in 1972.
The odd thin
Re:English units? (Score:5, Insightful)
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.
Re:English units? (Score:5, Funny)
Your Geek Pass has been revoked. You have one hour to clear your desk and leave the building. Thank you for your co-operation.
Imperial, not English... (Score:4, Insightful)
Re:Imperial, not English... (Score:2, Informative)
To add confusion to the mix, "Imperial" to a Canadian is the same as "English" to an American - i.e. not the same as "Imperial" to an Englishman.
Re:Imperial, not English... (Score:4, Informative)
Maybe, just maybe, we can start using the metric system? Isn't 100 years enough time to transition?
Re:Imperial, not English... (Score:5, Funny)
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.
Re:Imperial, not English... (Score:3, Informative)
Re:Imperial, not English... (Score:2)
Yep. That'll round so much more easily now...
Cheers,
Ian
Re:Imperial, not English... (Score:3, Funny)
(yeah, I meant imperial/metric measurements)
The right term is "U. S. Customary" (Score:5, Informative)
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."
How many Rods to the Hogshead?... (Score:5, Funny)
Or if that info. isn't available, how many stone per fortnight this ride has in lifting capacity.
TDz.
Re:How many Rods to the Hogshead?... (Score:5, Funny)
That depends if the ride is European or African.
0.86mm? That's a HUGE difference! (Score:5, Informative)
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.)
Re:0.86mm? That's a HUGE difference! (Score:2, Insightful)
Actually you'd be WAY better off it was 3 feet off. Even if it was say 10mm off, then the axle probably wouldn't fit or would be VERY noticably loose.
Instead you get the situation of something just fitting enough that it seems OK to the mechanic...
Re:0.86mm? That's a HUGE difference! (Score:5, Informative)
Re:0.86mm? That's a HUGE difference! (Score:5, Funny)
Lemmeee tell 'ya....
Here at Hyundai -
Our cars can take it!
Proving once again... (Score:3, Funny)
Re:Proving once again... (Score:2)
See, you did it wrong as well. 0.1.2.3.4.5.6.7.8.9
Re:Proving once again... (Score:2)
Yes, but the average American can spell.
English/Metric (Score:5, Informative)
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.
Re:English/Metric (Score:2)
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.
That is exactly what they were doing! Space mountain is also a very old ride, I have no idea as to the age of that contraption, but it's probably safe to assume it is older than 25 years.
Re:English/Metric (Score:2, Funny)
Also, since C is more difficult to remember (and use) than Visual Basic, I propose that C be outlawed once and for all.
Re:English/Metric (Score:2)
Actually, they did, around 1972, but they also introduced a virtually unlimited transition period so that people aren't confused with the new units. But so far, hardly anybody has switched to the better, scientific, superior, European SI units!
Re:English/Metric (Score:3, Troll)
Let's see here. Ok, distance is in miles and miles per hour. Liquid measurements are liters except when talking about beer, then it's a pint. Weight is in *stones* for christsake, a person's height is talked about in feet but a building/mountain height is usually in meters.
Re:English/Metric (Score:2)
Re:English/Metric (Score:2)
Integrated circuit pins and PCB track metrics are still measured in thousandths of an inch. Whether this is an americanism, or because of the difficulty in switching enough components simultaneously to drive demand, I don't know. But don't underestimate the power of Legacy - I'm sure this isn't the only example.
Re:English/Metric (Score:2)
Should we throw away everything with an English thread away?
We need to replace ALL of our sockets & drivers (yes, even the metric ones, because they're still 3/8", 1/2", or some other English drive size).
Want me to tear down my house because it's built to English specs too?
What about my water pump that's rated in psi?
My computer case needs to go because it'
Re:English/Metric (Score:5, 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!
Re:English/Metric (Score:3, Interesting)
This is one place where English units *definetely* make much more sense than Metric/SI units, *especially* for everyday use:
Tha problem is that a cEntigrade/Celsius degree is just too damn big to really be useful, espe
Re:English/Metric (Score:4, Insightful)
When water freezes is extremely relevant in "the real world". Whether there will be rain/wet or snow/ice outside is extremely relevant - at least where I live.
Having 100 as the boiling point of water isn't quite as important, but still pretty sensible. Usually, one degree C is small enough to be sufficient in accuracy (I have really never seen anyone change the thermostat by half a degree, as you claim), and having two points on a scale that sort of relates to the same thing (water, in this case) is pretty intuitive...
Re:English/Metric (Score:3, Insightful)
Re:English/Metric (Score:3, Informative)
In fact, the Kelvin scale is based on the Celcius scale. 0 degrees Celcius = freezing point of water, 100 degrees Celcius = boiling point of water. How hard is that?
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. So, for simplicity's sake, the fr
Fahrenheit's reasons (Score:5, Informative)
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.
Re:English/Metric (Score:3, Funny)
Google knows all:
14.4375001 [google.com]
Re:English/Metric (Score:3, Insightful)
The only really important historical exceptions I can think of are the Romans who used base-5 (but the way they wrote numbers was so horrendous that it didn't survive) and the Babylonians, who used base-60 (becaus
The horror (Score:4, Funny)
Mod points (Score:3, Funny)
Google's Cache (Score:3, Informative)
The US needs to catch up (Score:5, Insightful)
Re:The US needs to catch up (Score:4, Insightful)
Re:The US needs to catch up (Score:3, Funny)
So do we! When we say how many children the average family contains, it's always like 2.4, not "two and two fifths".
Just use google calc (Score:5, Funny)
HAHAHAH! No one uses hands anymore to measure distance! How ARCANE!
We use feet.
You don't ride horses, do you? (Score:3, Informative)
About time America left the stone age (Score:5, Interesting)
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...
About the same time /. posters actually RTFA? (Score:4, Insightful)
Also, there is nothing inherently better about the metric system of measurement, vs. the english system of measurement vs. any other standardized system of measurment. If something is measured at 1.5 inches or 38.1 mm, it's the exact same length. The only advantage is commonality and not having to do conversions (which is an advantage, I admit). But there is no inherent advantage as to how well one system can perform over the other.
Re:About the same time /. posters actually RTFA? (Score:3, Insightful)
how many inches in a mile?
Re:About time America left the stone age (Score:3, Funny)
-Rick
Beat the rush, switch to base 8 now!
US Conversion to Metric (Score:2, Interesting)
Noticable difference ? (Score:2)
I don't think that the average girl would notice that small a difference.
Re:Noticable difference ? (Score:3, Funny)
America versus the rest (Score:5, Interesting)
- imperial - metric
- Letter paper - A4
- Fahrenheit - Celcius
- AM/PM - 24 hr notation
- month/day/year - day/month/year
Anything I left out?
When will this stop? (Score:4, Interesting)
This incident (although caused by a transition TO the metric system) leads us to the question how many more years until we finally get rid of the imperial system. The US standard bureau has a page [nist.gov] that describes their effort in the conversion. They quote the metric conversion act of 1975, but i don't know how much has happened since then. How many years do I have to buy US stuff here in Europe that is half metric and half imperial? For god sake, even the UK has switched! Does anybody know a real time-table for the transition??
Obligatory Pulp Fiction quote:
If you ever run into a imperial system freak ask him to calculate how many square inch there are in a square mile
Not a metric/imperial drawing (Score:4, Insightful)
Someone ordered the wrong part. That's it.
This is why drawings should be controlled. Only current known valid drawings should be used for anything.
This problem is as basic as someone using patches for linux kernel 1.2.13 on a 2.6 series kernel
English units? (Score:3, Informative)
Messes up my own projects too (Score:3, Insightful)
Moan, moan moan... The metric is alive in the US. (Score:3, Insightful)
Karma Whoring Info Post (Score:4, Interesting)
A friend of mine in college in the late 80's did an internship with Disney Imagineering. At the time, they were redrawing plans for several attractions that were to be copied almost exactly from California and Florida version for use in Euro Disney. There was great concern that the Imperial to metric round-off would be a problem. The contractor's union in France mandated that they only use metric units in the blueprints, which is reasonable. But if you're trying to duplicate a ride that was originally designed in Imperial units, you need to keep in mind quite a few significant digits when you're measuring. For example, a section of track in a given ride might be 10 feet in the US. In metric that's 3.048 m. Would the French contractors really measure to that precision? Or would they round off to 3.05 or event 3.0? They were concerned that roundoff might be systematic causing the errors to accumulate in one direction. This was a big concern, and there were debates over whether some rides needed to be redesigned in metric from the start and possibly give up economies of standardized parts.
That this happened in Space Mountain is also interesting, because Space Mountain was the first rollercoaster to have ATIS (automated track inspection system). Since it was a tightly wound coaster in a confined space it was difficult to do visual inspections. ATIS uses two techniques to detect problems with the track. The rails are actually tubes and they're pressurized in sections. When small cracks start to develop, the pressure drop is detected. Sensors also time cars through different sections of the track. If there is a trend of cars slowing through a section over time, it indicates that the ties between the rails are starting to give. ATIS is so much better than visual inspections at detecting problems early that it's used on most modern roller coasters.
Canada: the metric, imperial and american systems (Score:3, Informative)
Mixing paradigms (Score:4, Interesting)
What bugs me is when they then only halfway use the Imperial paradigm.
Case in point: when the iPod Mini was announced, I went to the web page [apple.com] to check out the specs. 2" x 3.6". Not having any intuitive feel for what that might mean, I wandered around the office trying to borrow a ruler, and once I'd found one, started to draw an iPod-sized square on a piece of scrap paper.
A 2" line across the bottom was easy. Then I set about drawing the vertical. 3", then another 6 gradations... oh, wait a minute, each inch is subdivided into 16ths. Tricky. Grab calculator.
So please, either use mm, or go the whole hog and state 3 inches and (10/16)".
It's what I've been saying all along [humor] (Score:3, Funny)
These damned foreign countries. Don't you understand that the US run's the world. If the metric system were so great, wouldn't we be using it by now? Of course.
But we're not. Resistance is futile. You know why we don't use metric? Because it was invented by the French. Now, I love France -- cheese, Bordeaux wines, wonderful cusisine, art -- don't get me wrong. But the Froggies should stick to what they're good at and not try to mess with basic units of measurement. If your units were so great, why were you invaded by Germany twice in the last century? And who bailed you out? The Americans. And what units do we use? Not metric, mes amis, but good old SAE.
Convert to SAE. The lives of space probes, amusement park patrons, astronauts, and la France depend on it!
No Longer "English" units. (Score:3, Informative)
I buy beer in pints but I know that 1 pint is approximately 568ml (except in the US where pints are only 0.8 "English" pints). There are probably other things that we still measure in the same way that pre-industrial Brits did, but I can't think of any. The only other situation where pre-metric units have any relevance is in speed limits. Many tourists think they are "quaint".
I expect I am older than many people here - I can remember Neil Armstron walking on the moon. My wight is 114kg and my height is 1.82m. I could not care less about what it is in units of measure that would have been familiar to Henry VIII.
The English, and the rest of Britain are managing to move much of their units into the 20th/21st century. It is curious to see the USA stuck in the 19th...
Re:Standard system (Score:2, Funny)
Re:English units? (Score:4, Funny)
Re:The source of the problem (Score:5, Funny)
Mmm-hmm. So, clearly, defining length in terms of the feet of a 1200-year old dead Frankish king is a better choice?
Re:The source of the problem (Score:3, Informative)
Re:The source of the problem (Score:2, Informative)
MANY persons, otherwise well-informed upon general topics, believe that railroads were constructed especially for locomotives, as the best-adapted road for the accom- modation of that peculiar machine and its train of cars. They never call to mind that a locomotive is a modern invention, and, for want of access to works such as we have referred to, they are not informed that a railroad is an ancient institution (if we may ap
Re:The source of the problem (Score:2, Funny)
Re:The source of the problem (Score:3, Informative)
1. An imaginary great circle on the earth's surface passing through the North and South geographic poles. All points on the same meridian have the same longitude.
2. Either half of such a great circle from pole to pole.
So, the distance between the north pole and the Paris meridian == 0
Aren't these standards-based posts just wonderful for brining out the pedant in all of us?
Possibly you meant 'Parisian latitude'
Re:The source of the problem (Score:4, Informative)
Using Google... (Score:2)
Re:If the U.S. hates the french so much (Score:5, Insightful)
It would serve the french and the americans right!
See how stupid all this french or american bashing is?
Grow up, people.
Re:Pre-emptive rant reply (Score:3, Insightful)
Those of us to your north (or east, in my case) are somewhere between the european beurocracy and the american laissez-faire approach, but we haven't been hit with the recession in the same way. We do blame SARS and BSE with slowing the growth, but metric!?
And to state what a few dozen engineers have thought but not spelled out in the English vs. Imperial rant
Blah blah US economy blah blah (Score:5, Insightful)
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.
Re:for those of you that can't see the light.... (Score:4, Funny)
Re:Imperial measurements rock... (Score:4, Insightful)
Some of them are, some of them are not.
1 pound = 16 oz
1 stone = 14 pounds
1 foot = 12 inches
1 yard = 3 feet
1 US pint = 16 US fl oz
1 UK pint = 20 UK fl oz
1 Gallon = 1 pint
You're deluded if you think this mess has any value beyond familiarity (and, being unfamiliar with it, I had to look up all those conversions with Google Calculator...)
Maybe you'd like to go back to Imperial coinage too? 12 pennies to the shilling, 20 shillings to the pound, two shillings to the florin, 2 shillings and sixpence to the half crown...
Base 12. Right. (Score:3, Insightful)
A yard is 3 feet. A rod is 5.5 yards. A chain is 4 rods. A furlong is 10 chains. A mile is 8 furlongs. A league is three miles. A cable is damn nearly metric, at 10,000 links, or a bit more than 12 miles.
A pound is 16 ounces. A stone is 14 pounds. A hundredweight is 8 stone. A ton is 20 hundredweight. I would break the ounce down into drachm