1)
How many visible bolts were there altogether on each wall?
1.
Rashi: There were two bolts on each wall, each comprising two halves, 1 each of which ran along half the length of the Mishkan on the outside of the boards and met in the middle. 2
2.
Rashbam: There were five bolts on each wall that ran through the five rings that were fitted on the outside of each plank along the wall, one underneath the other.
1
Rashi: Measuring fifteen Amos each.
2
Rashi in Shabbos, 98b, concurs with the Rashbam here (Refer to 26:27:1:2 & 26:29:1.1:1.
