at the terminus "boulogne – pont de saint-cloud (rhin et danube)", because of the proximity to the seine, there are no tracks behind the station to allow the train to reverse directions. instead, trains are received alternately on each side of the platform and leave directly in the opposite direction. due to the narrowness of the "rue du château", under which line 10 passes, the stations "boulogne – pont de saint-cloud (rhin et danube)" and "boulogne – jean jaurès" have only one central platform used for both directions. after this last station, tracks run for to reconnect trains to "auteuil". tracks 1 (towards "austerlitz") must successively pass under the boulevard périphérique, followed by the platforms for the connections to "auteuil" and "murat" before ascending to service the station "michel – ange – molitor". in order to achieve this, ramps reaching a descent of up to a 40‰ grade are used. tracks 2 (towards boulogne) are separated by the loop on the level of the avenue du général-sarrail with a bend and a slope of 40‰.