In an episode of the former Television series, Mission Impossible, the team has to rescue kidnapped scientists. They fake an earthquake, so they can rescue the people. After crawling through a tunnel the come to a sewer with the ladder to the street, and it shows a metal ladder screwed to the wall which is found in a sewer. But when one of them reaches the man hole and is being helped out, you see very plainly the top of a step ladder..I doubt very much they use step ladders in sewers.