Diagram 4b in DBM

[landmeister]

A question about forming columns.

Why DBM's diagram 4b is not included in DBMM? Isn't legal such a formation now? Now contracting groups can wheel but all elements not behind the heading one just can move sideways. In DBM's diagram they are moving sideways AND moving forward. Is this possible in DBMM?

Thank you.

[landmeister]

Ehem.. just trying to hold your attention on my doubt, sorry. 

[Geoff Pearson]

Hi
I think the reason is that 4b is now not possible due to this line :-
"Elements of the group not yet in the column can move only sideways"
So only the single element wide column part of the group can wheel the last elements to join the column can only move sideways. see DBM 4a the "after" diagram A, B and C could become a kinked column but E, F,G and H could only move sideways to keep together in the group.

Best Regards
Geoff
 

[landmeister]

Ok. This is what I suspected. In effect, this sounds logic as rear elements distances are not measured when following the head one now. In this way you can have a kinked column and several elements not included in the column yet simultaneously as a single group.

Thank you very much.