RMweb Gold rodent279 Posted August 2, 2017 RMweb Gold Share Posted August 2, 2017 I'm curious to know how km posts are laid out on LGV lines, particularly the PSE line. Are they in whole km, 1/4, 1/2 & 3/4km, or 0.1 km intervals? I ask because I've dug up some timings from 1984, of a TGV on the PSE, heading towards Paris, from km 123 to km 100, and from km 47 to 34. Some of the times are a litlle astray, leading to speeds wavering between 257km/h & 276km/h, consistently, across whole km's. Now this could be due to timing inaccuracies on my part, or maybe I was mistaking a whole km for an xx.9 or xx.1km? Â cheers N Link to post Share on other sites More sharing options...
Guest pboeast Posted August 18, 2017 Share Posted August 18, 2017 The WTTs are probably accurate, as in the beginning, the trains did waver a lot. My friend's cousin is a retired SNCF timetabler, who was working on the LGVs from 1982 (LGV Sud-Est) to 1997 (New LGV Nord WTT) and he says that the trains wavered because the full provision at LPD (Lyon Part-Dieu) and PGL (Gare du Lyon) and the intermediate main stations- more Lyon through trains were stoppers at Dijon than now! The other thing is that French WTTs of the time included likely, recurring signal checks, which would slow the train down. It would help if you could send me the timetable, so I can check for you. Link to post Share on other sites More sharing options...
RMweb Gold rodent279 Posted August 18, 2017 Author RMweb Gold Share Posted August 18, 2017 Here is a transcript of my notes from that day. My method was very crude-I set the stopwatch running on leaving Toulon or Marseille, and at various points just noted the elapsed time. I only wrote down what is here. Why I went from recording 10th's of a sec to whole secs after km 100 I don't know. I'm not sure that would explain the wavering between 257 & 276km/h after km 44 though. I know my method is crude, but I'd still like to know whether LGV Sud-Est has posts every km, or 1/2km or 1/10km? Â cheers N TGV_Jul_1984_v2.xlsx Link to post Share on other sites More sharing options...
Guest pboeast Posted August 22, 2017 Share Posted August 22, 2017 LGVs were built differently, some on PSE and Med are upgraded, some not. Link to post Share on other sites More sharing options...
Guest pboeast Posted August 22, 2017 Share Posted August 22, 2017 Yes, it is correct, the posts are usually given in WTTs to the KM, but posts are often to the 50m. The train's wavering is roughly consistent, km 116-115 is delay prone, since Dijon line trains join the LGV here. Link to post Share on other sites More sharing options...
RMweb Gold rodent279 Posted August 22, 2017 Author RMweb Gold Share Posted August 22, 2017 So, if the posts are evey 50m, I could have mistaken a whole km for an xx.95, or xx.05? I'll have to do some working out, but it may explain the wavering between 257 & 276km/h, if I was recording times over 900m, or 1100m. Â Not that it matters now, it's 33 years ago! Link to post Share on other sites More sharing options...
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