A German manned torpedo carried its weapon underneath

Did the German manned torpedo use two torpedo bodies in line?

No. It used one extended manned carrier with a separate torpedo mounted underneath.

The unusual silhouette can look like two weapons joined end to end. The upper body carried the operator and provided the means of approach. The live attack torpedo was mounted beneath it for release against the target. This arrangement made the system a small delivery craft rather than simply a torpedo with a pilot sitting inside the warhead path. The layout provides a useful visual key for identifying German midget-attack equipment.