Full size breakers vs tandem breakers?

When two breakers are interconnected in various systems the simultaneous closure thereof may be dangerous, or even disastrous Thus, in a multiphase alternating

one slot chording From bar one the conductor goes to the top of slot one , than to bottom of slot four and then to bar two breakers similar to those

two breakers in one slot It will then slip in without being pushed into position 9 delete the slot on the panel covering the breakers Reinstall the panel Switch the

two slot Tandem breakers are only allowed in number and slots that they are aproved for Most 40 slot panels are only approved for 40 poles I am looking