When that route first went up in the early 50's it was the hardest in the country. The team was making little progress per day (only inches). They didn't want to rap back to the ground each night so they invented the port-a-ledge. It still hangs in its original place today. God bless them and their design which ushered in new sleeping developments and therefore more difficult climbs on Big Walls such as the one in your picture.