Bicycles - fitting a disc brake on a frame not designed for one, torque and force fun

Hello everyone, I am a new member here. Nice place you have; I have been reading on here again and again and figured it would be the right place to ask you about a problem I just can't get sorted out myself.

It is about bicycles and disc brakes. I have an aluminum track frame that I want a rear disc brake on. The frame does not have disc brake mounts. However it does have a mount for a "normal" 1-bolt road type caliper brake.
The frame looks pretty much like this: http://i.ebayimg.com/t/Unknown-Lv2-55cm-Track-Frameset-Cane-Creek-Headset-included-/00/s/MTIwMFgxNjAw/%24(KGrHqFHJEgE-muhtjmCBPz8dLEK%2B!~~60_57.JPG

I have searched the internet over and over for retrofitting disc brakes, have looked at countless adapters and diy-solutions. I have made some drafts of concepts I have been thinking of, here they are:



I think the pictures are basically self-explanatory, so I will just ask you what you think of these designs and where you see possible drawbacks or disadvantages.
The adapting system should be as light and as safe as possible while not altering the frame.

I would be very grateful for any input on this. Thanks so much!

 

Thanks berkeman. I have spent the last weeks gathering information around this topic and I think I have seen most of the retrofit disc brake solutions that can be found on the web. The point where I seem stuck is how to estimate the forces or, since they can be calculated, rather how to estimate the ability of the frame to handle the forces present in the numerous concepts and what concept is the most sensible.