legion marching formations

[A_Volpe]

One possibility is having the ranks 'staggered', somewhat like a checkerboard, being that the 2nd row of troops are 'offset' to the side behind the first row of troops. It likely was based off of, or influenced, or, evolved? from the "Quincunx" formation seen during the Republic, say during the 2nd Punic Wars.

Sort of like this:

^ front line ^

0-0-0-0-0-0-
-0-0-0-0-0-0
0-0-0-0-0-0-

( 0 = Legionary; - = space between, as I can't get it to look the way I want)

The idea likely being 3-fold: 1. it maximized your "volume" or spread of Pila when thrown 2. it maximizes the amount of 'fighting space' per legionary 3. It allows easier maneuvering in the 'countermarch', where the rear-ranks move forward and refresh/relieve the front rank who had been fighting. (It has been estimated at about 5 minutes worth of fighting per 'change') - but for a countermarch also allows a 'continuous fire' if you will, for the Pila as well.

Certainly the Romans employed several tactics and maneuvers, and they certainly can branch off from this one.

To 'deploy' in something like this, would probably been very simple, being that when marching perfectly aligned:

0 0 0 0 0
0 0 0 0 0
0 0 0 0 0

When the order is given, the 2nd rank steps to the left or right to align with the 'space' between each Legionary in their row, that can be done standing or marching, and probably was done both by the Romans.

That spacing, or interval, by the way, has also been suggested to be 3 feet between each Legionary. (I think the spacing is noted by Polybius or Vegetius?)
A number of reenacting units use a pretty simple 'dressing' technique, extending the right arm to it's full length, with knuckles just barely touching the scutum of the fellow Legionary to your right, dressing or pushing down the left side. - This being taken partly from "Pike and Shot" techniques in the 17th century in Arms/Drill manuals, such as Hexom (1637) and DeGheyn (1620's)....Which are in turn, influenced from Classical sources such as Caesar and Alexander the Great, and 'manuals' like Aelian's Tactics, Tactitus, Polybius, and Vegetius.

It's mentioned (although I forget which manual/author at the moment, I want to say Hexom), that the [pikemen] are to space themselves "akinbow" ("a keen (el)bow"), being elbow-to-elbow with hands on hips. That is for "Order" spacing ("Open Order" for marching not under threat, fingertip-to-fingertip; when packing in tightly to 'receive a charge of horse' (cavalry charge), the Pikemen move in and close shoulder-to-shoulder, at the "Close Order".)