Anti-Zombie Ladder

I've been thinking of technology that will help us to live long when the zombies come. Tonight I'll unveil the first piece of a long stage, low-key anti-zombie security system. I've based it on three basic principles:

• Long term survivors will be calmer than those who die off quickly.
• The primary distance between humans and zombies will be cognition.
• The best security measures will need to increase security, though not necessarily guarantee it absolutely, without constant vigilance in case the guards become occupied elsewhere.

This is also based on the idea that one could make this with a blow torch, some steel tubing, and a hammer. It's not something that requires really complex machinery to build.

The principle of the anti-zombie ladder is this: the ladder is composed of steel rungs that are rounded in some places and flattened to razor sharpness in others. The razor sharp places will be in a pattern, however obscure, that will be easily memorized by humans using the ladder to go up and down. Any zombie that attempts to climb the ladder will most likely lose fingers, thumbs, and toes to the blades until they are physically unable to continue the attempt. The ladder could be out over a good drop, meaning that any zombie that attempts the climb and has a hand sliced off will probably fall down into a pit and not litter the floor below. These ladders might not be the primary security, and should not be, but will enable humans to enter and leave in certain areas without the use of complex drawbridges.

The idea of patterns as protection can be expanded to include floors that are wired to electricity in some spots or any similar trap system.

One potential pattern (1122) is shown below, with the red lines being the razors.