TGV Atlantique 325

thingiverse

February 1, 1990 at 15:30, the train 325 returned to the Châtillon workshops for a long time. It had then established a new world record of 482.4 km/h on December 5, 1989. The technicians had until March 1 to carry out a new program of modifications to allow for the collection of new data and perform a public stunt around 500 km/h. This second phase of modifications was intended to take advantage directly of the experience gained during the first phase. The axles of the power cars 24049 and 24050 were removed and sent to the Bischheim workshops in Alsace on February 2 to be adapted to larger wheels of 1,090 mm. The head axle of power car 24049 was equipped with strain gauges and returned to Châtillon eight days later on February 22. Originally, the second axle was also supposed to be equipped in this way, but the deadline of March 1 did not allow it. To adapt to larger wheels, special brake shoes were machined for the power cars 24049 and 24050. With a thickness of 15 mm, only two emergency stops were guaranteed. On February 6, the trailers were lifted and trailer R6 was removed from the train. This brought the train 325 to the minimum composition possible since trailer bar R4 served as the "keystone" in the articulated design of the TGV. The train 325 now weighed 250 tons and measured 106 meters long. From February 7 to 14, the remaining three trailers underwent further modifications. The 25 kV roof line that powered the lead power car was replaced by a simple cable; this allowed the isolators that supported it between the cars to be removed and which disrupted air flow. Rubber membranes were installed to cover the space between the trailers and bogies, and Y237B bogies were raised by 40 mm. Large fairings were installed in the gap between power cars and trailers. These "snowplows" mounted under the attachments were designed to prevent the formation of a low-pressure zone between vehicles, which had caused significant drag during previous tests. On the power cars, metal sheet guards were attached to the bogies, and the front car was extended downward by 10 cm to compensate for the larger wheel size. Finally, a removable spoiler was installed on the nose of power car 24050. The aerodynamic improvements were expected to result in a 10% reduction in drag. During the previous test phase, atmospheric drag had reached a value of 9 tons at a speed of 460 km/h. On the new version of train 325, this value was not expected to be reached before 500 km/h. On February 27, 1990, after coupling the two trains, train 325 left the Châtillon workshops for the second time, with two days ahead of schedule. This time, it took 2000 hours of workshop work to make the modifications. The second test campaign, which culminated in the establishment of the world speed record of 515.3 km/h is summarized in the chronology of the record below.