Quote:
Originally Posted by maxnz
Let me ask this: Where exactly was the problem on the portcullis? I know what the problem is but I just want to know what part of the portcullis caused the problem. Then we could try to think of a new portcullis that removes this problem.
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The problem is, the springs on each side are 40 pound constant tension springs which means the actual door within the portcullis is 85 pounds total. With the springs attached, the door can be easily raised to about 10 feet at which point the assembly becomes very top heavy and tippy. Without the springs attached, the door can be lifted even higher and I understand that may have caused an incident or two. The springs themselves are metal ribbons with, while not a sharp edge, and edge that can cut ungloved fingers as the door moves up and down. Think of someone running 4 feet of the edge of a tape measure across your fingers. The wheels at the bottom of the door present a crush hazard as they roll up and down as well.
The assembly when finished is very easy to tip and has no hand holds or way to lock the door in place.
So, an improved portcullis is:
- lighter.
- has no exposed counterweight components.
- has fewer sharp edges.
- has a door that can be locked in place during transport.
- has handholds for the field reset folks.
I'm sure there's more.