Talk:TGV world speed record

Bridge over Loir measurements wrong

Bridge over Loir is stated as "175 m (1100 ft) bridge". This is wrong in multiple ways,

1. 175 m is 574 feet (or 1100 feet is 335 meters)
2. this is probably the length of the bridge not the height (if you look at the map at TGVweb map here its rather flat)

It is wrong in the source. Any French train fanatics know the answer ? (I'd sign-in but I'm on another PC and forgot my password) 79.0.193.28 17:38, 4 April 2007 (UTC)

It is 175 m, and I got the conversion to feet wrong back when I wrote the TGVweb article in 1995. Good catch. --Ctillier 04:51, 6 April 2007 (UTC)

TGVweb

Most of this article is from incredibly detailed articles borrowed from TGVweb. While it's not a copyvio, it's still totally out of place in Wikipedia, and since it's available elsewhere on the web, there's little reason not to delete huge chunks of it to make the article more readable, as currently it's totally impenetrable. --82.45.163.4 04:14, 12 April 2007 (UTC)

As the author of TGVweb, I generally agree, although you should not count on TGVweb being around forever. I haven't maintained that website in several years, and I am hoping that Wikipedia can take over as a better source. A major copy edit and pruning is in order to make the material more suitable to an encyclopedia. If I only had the time... --Ctillier 07:15, 16 April 2007 (UTC)

Catenary tension

Can the author of this page produce some more citations about the track modifications required to support the speed record runs? The article discusses the increase in mechanical tension applied to the catenary to increase its mechanical wave speed above the planned speed of the train. Figures as high as 3200 daN (deca newtons, i.e., 32,000 N) are given. The cross-section of the copper contact wire is given as 150 mm^2. This corresponds to a tensile force of (32,000 N / 150 mm^2) = 213 MPa (megapascals). But the yield strength of 99.9% pure copper is given by Ultimate tensile strength as only 70 MPa. Would some of this tension be taken by the 65 mm^2 bronze support wire? Bronze is harder than copper, but I would expect the force to be applied to the contact wire because it's the one being pushed by the pantograph. Does the contact wire perhaps have a steel core? Steel (and even some aluminum alloys) have a vastly higher yield strength than copper, so it would only have to be a fraction of the wire's area. Karn (talk) 01:31, 4 July 2011 (UTC)

Good catch. Wouldn't it be better to let the perturbation trail the pantograph, lowering line stress? — Preceding unsigned comment added by 86.106.92.152 (talk) 08:51, 22 April 2012 (UTC)

The typical material for high-speed overhead contact lines is a copper-magnesium alloy with a magnesium content of 0.5% by weight. The yield strength of this alloy is 4900 daN.. See here.--Pechristener (talk) 16:26, 23 December 2023 (UTC)