Not quite, Norman. TTM has dual diaphragms in his brake cylinders (a spacer with separate air inlet pipe and second diaphragm makes effectively two cylinders one on top of another), and a separate air tank and dual circuit foot valve, so is a Dual-circuit system, but they are not spring chambers.
I'm looking at the possibility of spring brake chambers but not easy due to lack of "headroom" for cylinders. On a Scammell Constructor for example it is easy to put an extra brake actuating lever and spring chamber on, which is what I'm trying to scheme for the WLF. DT may be easier if more space available.