When a train enters this tunnel, it is brought to a complete halt. The electro-magnetic propulsion from a Linear Synchronous Motor (LSM) launches the train out of the tunnel, but instead of launching the train forward like the initial LSM launch out of the station, the LSMs in the tunnel first propel the train backward. The momentum from the launch is enough for the train to travel partially back up this dive loop, but gravity quickly pulls it back into the tunnel. While there, the LSMs fire again and boost the train's speed, adding forward momentum on the second launchW. This additional increase in speed is needed because, after the train leaves the tunnel, it perform a left turn and then makes the big climb up and over the massive vertical loop.
©2016 Joel A. Rogers.