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Politics : The Environmentalist Thread -- Ignore unavailable to you. Want to Upgrade?

To: maceng2 who wrote (19921)	1/30/2008 4:24:37 PM
From: neolib	Read Replies (3) \| Respond to of 36918

This must lead to all sorts of problems. Yes, it lead Hugh to make the idiotic statement that Kg x m = work. This is because in the English system they are very sloppy with "mass" and "weight", using pounds (lb) for both. If you are careful you use lbm for mass and lbf for force. In SI, Newtons are Force = mass x accel = kg m/s2. Sloppy Hugh thinks Kg will do, so he has now decided he can lop off m/s2 (three units) in defining work, whereas before he tossed in 1/s (one unit) at his whim. I give up with him. He is most definitely going downhill.

To: maceng2 who wrote (19921)	1/30/2008 5:35:17 PM
From: Thomas A Watson	Read Replies (2) \| Respond to of 36918

I don't know what a long time is, but all work I did for Nasa used English Units. Torque and Load were measured in Lbs. The equipment doing the work was calibrated in Lbs and Ft-Lbs. But a units error did not cause the big Challenger Bang. acute.ath.cx On January 28, 1986, at 11:38, Mr. Watson was at lunch with a group of students. The students were taking a course authored by Mr. Watson on the use of Computer Aided Schematic capture and netlist database generation. In the restaurant the TV station broke to live coverage of the the launch of STS Challenger. Challenger exploded 73 seconds after takeoff. Television film footage captured the tragic explosion and its aftermath, as smoke trailed out of the craft and it fell to the ocean. All seven crew members died due to a faulty "O-ring" seal failed in the solid-fuel rocket on the shuttle's right side. Flames escaped through the failed seal. The flames burned through the shuttle's external fuel tank and a support attaching the rocket to the tank. The rocket broke loose and pierced the tank. Liquid hydrogen and liquid oxygen fuels ignited, tearing the shuttle apart. The shuttle launch program was not resumed until designers made modifications and National Aeronautics and Space Administration (NASA) management implemented stricter regulations regarding quality control and safety. The accident and the ensuing investigation into its cause temporarily halted the space shuttle program. Shuttle missions resumed on September 28, 1988, with the flight of the shuttle Discovery. In 1990, as a result Challenger accident NASA contracted with the PowerDyne Division of Raymond Engineering for the development the Hydraulic Ultra Sonic Bolting System. Mr. Watson as a Consultant to Raymond Engineering designed and developed the HUBS control program. The HUBS program was a real time embedded control program for the controlled sequential bolting of the joints of the solid rocket boosters. The program maintained a database of the bolting process and provided complete calibration of pressure and ultrasonic load measuring instrumentation. To provide realtime signal emulation Mr Watson designed and fabricated the HUBS Electronic Emulation Simulator.

To: maceng2 who wrote (19921)	1/30/2008 10:47:11 PM
From: neolib	Read Replies (2) \| Respond to of 36918

Yes, NASA lost one Mars craft due to English units, but IIRC, the Euro's lost an Ariane 5 rocket due to a similar type of screwup. The controller used some factors or constants from the Ariane 4 rather than the correct ones for the Ariane 5. Ouch!

To: maceng2 who wrote (19921)	1/31/2008 8:08:31 AM
From: HPilot	Read Replies (1) \| Respond to of 36918

I noted that many people still use imperial units in the USA. This must lead to all sorts of problems. This was a big eye opener... The auto industry has converted to SI for the most part. I have lately been working on a Ford Taurus, all of the engine, not just the bolts are metric, most of the bolts under the hood are metric, but some components are not. The nut for the power line from the alternator is for some reason not. Of course all American cars have American Standard lug nuts on the wheels for some reason. The aviation industry is in transition but really only the newer jet aircraft and space craft. The rest is all American Standard which is the English system with our own standards of thread and bolt size. I work in the heating and refrigeration industry and its is all English. It does cause problems, I preferred SI in college.