Did the Macedonian Phalanx practise othismos with its sarissas?

[Justin Swanton]

Except it won't work with any peltae that are not nearly flat- hense "not too deep".  See why you cannot overlap deep peltae below; two methods of overlap.  The only way to have a straight line like you show is to have the peltae angled anyway. I am actually not against an angled line, as long as both lines angled obliquely, they still meet even. It also adds the tendency to win on the right, or leading edge, but it would look much different that your image above.  My bigger problem is that overlapping on such a sloped and rimless shields would not be very effective. There is no need to  make too much of overlapping in any case, a shield wall functions fine without it. The main benefit is the tighter physical link between men that makes moving in unison easier.

A shieldwall without overlapping may work but I prefer to take the sources at their word - close order 48cm-wide files and shields at least 60cm wide, which makes overlapping shields mandatory unless you try that peculiar idea of holding the shields angled at something like 60 degrees to the forward facing of the phalangites. My own impression is that the phalangite shields faced forwards but were angled a bit when overlapping to keep the line straight, as you suggest.

I still wonder why Macedonian shields were so deep. Must have been for a reason.

[Patrick Waterson]

I still wonder why Macedonian shields were so deep. Must have been for a reason.

Did they form a 'bowl' around the left elbow?  I have in mind the Swanton experiments with the left elbow seeming to fit naturally through the armgrip at the centre.

[aligern]

Perhaps it is related to deflecting thrusting weapons? A spearman , with the spear in the right hand and the shield on the left arm can move the shield to deflect incoming spears. However, holding a pike in both hands means that the user cannot influence deflection as easily. Perhaps a flat form to the  pelta might mave made it easier for incoming spears to penetrate.
Roy