Yes George, very well in tension on clockwise rotation, which is why this style of brake was used on hoists such as Cranes, Draglines.
To get this to work equally in both directions requires a rocking link in the leverage, lesser band contact of 220° and more space to occupy than I actually have; also which I can't compute the required points without dismounting the drum from the axleset and developing a working setup on a pegboard. All those calculations needed are required to effect the most braking effort without distortion of any components. The original Mancha design of screw activation closed the band in a clasp movement and it is better for me to move on and attempt that.
The Post Brake was developed for Mine Hoists where repetitive accurate positioning of the cage/skip, I would attempt to copy those if I had more time but for all intent and purpose clasp type brake blocks of the type we see on older diesels would be quicker and easier and also less complicated.
However since the RR clasp type brake requires some larger surface(wheel dia.) than I have in my brake drum, I'm persisting with the band, have just rebuilt that with centre pivot point and modified ears to allow a reeved cable to draw the ears together. Whether it works, I won't know until after the cable has been made up sometime this week.
The Mancha Mk4 band brake setup. Note that this mechanism is vertically inline with the Flywheel mounted drum, not at all like my Brakedrum on axle setup. To fit this would again require the modification to fit Scissor levers to impart the clasping movement 90°.
This has been a rather interesting and challenging time.