this map is from 1941
(it was used as military map in that year,although you will see real time is 1937
,but in the down right place is note that map is edited in October (I believe) by General Staff of the Red Army.Very rare, and thanks to year 1937 also available to share.
So I you can see,there is no bridge in Stalingrad at that time,however today one bridge exist south of Winnovka(Akatovka is under Winnovka)
But it is a modern bridge:
(image is big,so I placed a link)
other transporter bridge (cool thing) was constructed in 1955 but later it was demolished.
So that I know about "real" bridges,and if you ask me none existed at the time,only thing available were ferries.
@Janos...most of western bank,including one factory,but Russians held out in Rynok,small place on the extreme north of Stalingrad.(coincidence or not but modern brigde is not war grom there)