Whether it was ratlines in the sailing ship era or vertical ladder in the steam era, sailors have had to climb considerable vertical distances with no protection from a fall. This would have to be done at all times of day or night and in every type of weather. Throughout time countless sailors have been maimed or killed from falling during a climb. Oh well, you can't make an egg without breaking a few eggs, their political masters would say. Send out the press gangs! Finally navies wised up and realized that a trained sailor is a valuable commodity and the sailor's morale would improve if they saw their safety mattered. In most modern navies, if there is a long run of vertical ladder, there is a safety cage encircling designed to prevent a sailor from falling outward. L'Arsenal has had the foresight to care for your miniature sailors in 1:400 scale. Jacques and the gang have produced brass photo-etch set AC400-39, which includes six safety cage vertical ladders. Simply use a small diameter tool, such as a pipe cleaner as a template around which to roll the cage.