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ProfessorF
What's a life?
Joined: Thu Apr 23, 2009 7:56 pm Posts: 12030
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Thermite welding is widely used to weld railroad rails. The weld quality of chemically pure thermite is low due to the low heat penetration into the joining metals and the very low carbon and alloy content in the nearly pure molten iron. To obtain high-quality railroad welds, the ends of the rail being thermite welded is usually preheated with a torch to induce a good fusion with the working pieces of metal. Because the thermite reaction yields relatively pure iron, not the much stronger steel, some small pellets or rods of high-carbon alloying metal are included in the thermite mix; these alloying materials melt from the heat of the thermite reaction and mix into the weld metal. The method was patented by John H. Deppeler Jr. in 1928 while working for the Metal and Thermit Corporation. It is United States patent number 1671412. Typically, the ends of the rails are cleaned, aligned flat and true, and spaced apart 25 to 75 mm (1 to 3 inches). A mold made of graphite is clamped around the rail ends, and a compressed-gas torch is used to preheat the ends of the rail. The proper amount of thermite with alloying metal is placed in a refractory funnel, and when the rails have reached a sufficient temperature, the thermite is ignited and allowed to react to completion (allowing time for any alloying metal to fully melt and mix, yielding the desired molten steel or alloy). The reaction crucible is then tapped at the bottom (leaving the aluminium oxide in the crucible), the molten steel flows into the mold, fusing with the rail ends and forming the weld. The entire setup is allowed to cool. The mold is removed and the weld is cleaned by chiseling and grinding to produce a smooth joint. Typical time from start of the work until a train can run over the rail is approximately one half hour.
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Wed Oct 28, 2009 12:20 am |
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forquare1
I haven't seen my friends in so long
Joined: Thu Apr 23, 2009 6:36 pm Posts: 5153 Location: /dev/tty0
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I learnt that Madness' "House of Fun" was about buying condoms...Perhaps obvious, but I overlooked that one for many years...
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Mon Nov 30, 2009 10:01 am |
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l3v1ck
What's a life?
Joined: Fri Apr 24, 2009 10:21 am Posts: 12700 Location: The Right Side of the Pennines (metaphorically & geographically)
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Mon Nov 30, 2009 11:34 am |
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oceanicitl
Official forum cat lady
Joined: Fri Apr 24, 2009 8:04 am Posts: 11039 Location: London
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The video of him going in to the chemist to buy condoms didn't give it away then? 
_________________Still the official cheeky one 
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Mon Nov 30, 2009 12:27 pm |
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John_Vella
I haven't seen my friends in so long
Joined: Fri Apr 24, 2009 7:55 am Posts: 7935 Location: Manchester.
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Neither did the lyrics, apparently 
_________________John Vella BSc (Hons), PGCE - Still the official forum prankster and crude remarker  Sorry  I'll behave now. Promise 
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Mon Nov 30, 2009 12:30 pm |
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finlay666
Spends far too much time on here
Joined: Thu Apr 23, 2009 9:40 pm Posts: 4876 Location: Newcastle
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Ed Byrnes last DVD (I think it was Pedantic and Whimsical) sold fewer copies than the WAG's Workout  Apparently this was because Ed Byrne bought the WAG's Workout 
_________________TwitterCharlie Brooker: Macs are glorified Fisher-Price activity centres for adults; computers for scaredy cats too nervous to learn how proper computers work; computers for people who earnestly believe in feng shui.
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Mon Nov 30, 2009 12:41 pm |
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Fogmeister
I haven't seen my friends in so long
Joined: Thu Apr 23, 2009 7:35 pm Posts: 6580 Location: Getting there
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Today I learnt that no matter how many times you tell people something they will always forget it!
First rule of Heldesk: NEVER BELIEVE WHAT THE USER TELLS YOU! If they say that somethings goes wrong when you do xyz then FRICKING DO xyz and see if it goes wrong!
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Mon Nov 30, 2009 1:26 pm |
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pcernie
Legend
Joined: Sun Apr 26, 2009 12:30 pm Posts: 45931 Location: Belfast
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That my job (in the sense of where I'm located now) is safe 
_________________Plain English advice on everything money, purchase and service related:
http://www.moneysavingexpert.com/
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Mon Nov 30, 2009 1:35 pm |
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fakesnake
Occasionally has a life
Joined: Fri Apr 24, 2009 6:30 am Posts: 138 Location: lost in the wilderness
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 |  |  |  | ProfessorF wrote: Thermite welding is widely used to weld railroad rails. The weld quality of chemically pure thermite is low due to the low heat penetration into the joining metals and the very low carbon and alloy content in the nearly pure molten iron. To obtain high-quality railroad welds, the ends of the rail being thermite welded is usually preheated with a torch to induce a good fusion with the working pieces of metal. Because the thermite reaction yields relatively pure iron, not the much stronger steel, some small pellets or rods of high-carbon alloying metal are included in the thermite mix; these alloying materials melt from the heat of the thermite reaction and mix into the weld metal. The method was patented by John H. Deppeler Jr. in 1928 while working for the Metal and Thermit Corporation. It is United States patent number 1671412. Typically, the ends of the rails are cleaned, aligned flat and true, and spaced apart 25 to 75 mm (1 to 3 inches). A mold made of graphite is clamped around the rail ends, and a compressed-gas torch is used to preheat the ends of the rail. The proper amount of thermite with alloying metal is placed in a refractory funnel, and when the rails have reached a sufficient temperature, the thermite is ignited and allowed to react to completion (allowing time for any alloying metal to fully melt and mix, yielding the desired molten steel or alloy). The reaction crucible is then tapped at the bottom (leaving the aluminium oxide in the crucible), the molten steel flows into the mold, fusing with the rail ends and forming the weld. The entire setup is allowed to cool. The mold is removed and the weld is cleaned by chiseling and grinding to produce a smooth joint. Typical time from start of the work until a train can run over the rail is approximately one half hour. |  |  |  |  |
That takes me back I spent 10 years on contract with irish rail, the welding used to make quite a show when done in the dark.
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Mon Nov 30, 2009 4:25 pm |
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oceanicitl
Official forum cat lady
Joined: Fri Apr 24, 2009 8:04 am Posts: 11039 Location: London
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The fault is usually between the keyboard and the chair 
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Mon Nov 30, 2009 4:46 pm |
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EddArmitage
I haven't seen my friends in so long
Joined: Thu Apr 23, 2009 9:40 pm Posts: 5288 Location: ln -s /London ~
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That'd be the 10-T error. (8-p)
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Mon Nov 30, 2009 4:47 pm |
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ProfessorF
What's a life?
Joined: Thu Apr 23, 2009 7:56 pm Posts: 12030
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The Giant Octopus can weigh up to 600lbs and may have a bite pressure of up to 1000lbs.
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Mon Nov 30, 2009 6:14 pm |
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EddArmitage
I haven't seen my friends in so long
Joined: Thu Apr 23, 2009 9:40 pm Posts: 5288 Location: ln -s /London ~
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That's not a pressure! Booooooo!
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Mon Nov 30, 2009 6:18 pm |
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ProfessorF
What's a life?
Joined: Thu Apr 23, 2009 7:56 pm Posts: 12030
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Hey, I know, I was wondering what the distribution of that weight is, but it's taken from here: Source. Anyway, sharks go up to 4 tons of pressure. 
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Mon Nov 30, 2009 6:19 pm |
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EddArmitage
I haven't seen my friends in so long
Joined: Thu Apr 23, 2009 9:40 pm Posts: 5288 Location: ln -s /London ~
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Do we assume PSI then? Do those values seem remotely sane? I'm not very good with imperial 
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Mon Nov 30, 2009 6:21 pm |
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