This train is a S446. 446.051 is the correct numeration. This model serial number is called by the central car, which is the half of the even car (102), the odd one is the even one -1. You can easily see the difference between 446 and 447 in the letter "M" on the right of the car serial number, 447 is yellow and 446 is white (only on red units). In Madrid there is only 446.