To become an STMS, you need to do the TTM worker course, then the TMO course, plus practical assessment. Then to STMSU for two days, then to STMS Cat A and Cat B, then to a practical assessment in both categories. That would be a day’s training in TTM worker, another day’s training in TMO, two days for STMSU, a day of each Cat A and B, then one day for practical assessments for both Cat A & B.