I've mentioned in other similar themed threads that caution should be used when comparing anti-riot forces and historical formations such as those used by the Romans. I believe other than the obvious differences in training (riot training is usually not the primary aspect of police), environment (urban vs. open rural areas), and equipment (bludgeoning weapons and rubber bullets vs. sharp iron tipped and javelins, spears and swords), the main difference between modern riot police and Romans was intent; the riot police are certainly not trying to kill their opponents, just contain them or drive them off with minimal casualties, while the Romans must certainly were trying to kill their enemy using the most available and destructive hand carried weapons then available.
That said, I've been following the turbulent Kiev riots currently happening and have noticed a few interesting pictures that may shed some light on certain aspects of fighting in closely packed formations scuta/thureos shields. Humor me, please.
The shields:
[img width=500]http://blogs.ft.com/photo-diary/files/2013/12/ukraine.jpg[/img]
This is the standard Ukraine riot shield, which cosmetically is similar to an Imperial Roman scutum, like those portrayed on Trajan's column. Based off gross measurements taken from the above picture, the shield appears to be waist high, when rested on the shield bottom, and slightly larger than shoulder width with a thick winter coat, making it approximately 40 inches tall and 22 inches wide, with a small curvature to it to protect the individual's flanks. While the shape, curvature, and width are "similar" to a Roman imperial, the shield is a bit shorter than most Roman shields and is attached to the wearer by a horizontal mounting system, where the left arm is strapped to the shield, similar to an aspis or medieval heater shield, versus the centered horizontal hand grip of a traditional scutum (the mounting system of Ukrainian shields is not shown in this post but is based off of other pictures of Ukraine rioting). Additionally, the Ukraine shield is of sheet metal, not plywood, and contains vent holes in the top to see through. All told, other than the method of carrying, I'm sure any Roman would have LOVED to have carried the modern replica shield over their own plywood version.
Additionally, the riot police's main weapon for hand to hand combat is a 20 inch baton made of wood or possibly some sort of wood or hard plastic/metal mixture. While some may argue that the baton is meant to be stabbing with, no one can argue with the fact that a sharp sword takes about 1-4 pounds of pressure to pierce human skin and destroy muscle, veins, organs, etc, while a very hard strike with a solid baton might break bones or rupture a nerve plexus. The differences between an actual sharp sword and a bludgeoning club are really night and day in terms of their effects, but somewhat similar in terms of their usage. Similar short slashes and jab attacks with a baton are similar to the attacks possible with a Roman Gladius. With the same move done with each, a sharp sturdy sword requires less energy to be many times more destructive. Again, a clear indication that the riot police aren't trying to kill anyone, at least not at the tactic level or arming them.
In previous threads, certain members have been proponents of the idea that the standard Roman legionnaire combat formation would entail close ordered ranks, with little to no distance between shield edges, or with overlapping shields. When discussed, the assertion was made that these formations would not limit effective use of the sword.
Ukranian Riot Police in a "Testudo"-like formation, being attacked by a single club-waving adversary:
[img width=500]http://cdn.theatlantic.com/static/infocus/ukraine012214/s_u14_18167934.jpg[/img]
To present my argument, this picture needs to be taken completely in context. The riot police of the Ukraine Ministry of Interior clearly have weapons capable of defeating all the attackers present (a plethora of AK platform rifles) but remain hidden behind their shields, allowing brazen attacks by their adversaries. This could be the result of morale (not agreeing with gov'ts order to crush dissidents), orders (don't cause unnecessary bloodshed on live television, knowing everything is recorded for posterity), or simple tactics (the chief watched 300 and Rome on HBO too many times). From the above picture, I think it can reasonably argued that a closely arrayed fighting formation absolutely maximized defensive coverage, especially against missile weapons. For what their mission is, against the weapons and tactics most commonly used by the protesters, ineffectual individual attacks with a penchant for intense beserker attacks and by *relatively non lethal missile attacks, the above formation makes sense.
* I say this because I think there is an unspoken understanding between riot police and rioters that certain methods of attack, such as prevalent use of firearms or incendiary devices, can and will escalate the situation into something a little more than a riot, notably a massacre. Molotov cocktails are dangerous no doubt, but against individuals, rarely kill them. Same for chunks of concrete and clubs. If you bring pipe bombs to a street riot, all bets are off in terms of playing nice.
However, as earlier mentioned in previous threads, the above picture clearly shows that with overlapping or nearly touching shields, it seriously limits the availability of possible offensive attacks. Take away the overhead protection from shields in the second and after ranks, and it removes the roof of "testudo" but remains a shield wall. Of the dozens of thrusts and cuts possible to use with a 25-27 inch long Gladius Hispanensis, or a slightly shorter 22" Mainz, or even a 19" Pompeii Gladius, not to mention the possible offensive attacks using the umbo/shield boss of a scutum or its reinforced bottom edge, fighting in close ordered ranks limits attacks to an overhand stab, over the shield's top, against an enemy's face, neck or upper back. This maneuver will also mostly be blind, as the attacker will also be in the enemy's danger zone and therefore must remain hidden behind their own shield.
Should one of those riot police in the above formation decide to use his baton or shield in any method other than the above overhand downward attack, he would have to break away from his shield mates, opening up a hole in the line, which is against the whole reasoning to form a shield wall in the first place.
I posted the link to this gif earlier in this thread, I think it's a great example of the difficulty a closely ranked formation has crossing terrain obstacles:
[img width=500]http://static.dyp.im/wPE2vX7vv5/7f8cb9ae220b7a847a277c14e86b123d.gif[/img]
First, this gif shows an intimidating sight to behold, a large group of armed shield bearing riot police, advancing in unison, as a team. If I were a protester facing them, I would be scared, which is no doubt the whole point. However, it must be noted that the only reason they were able to pass over the obstacles in front of them, a poorly constructed barricade, was because this formation was NOT in contact with the enemy. Had it been pressured by intense missile fire or an opposing armed formation, the temporary confusion and loss of order would have been seriously detrimental to the overall integrity of a formation designed around integrity.
The barricades of short stacks of tires and overturned tables could very easily be substituted in ancient battles with dead bodies of men or horses, fallen trees, a large thorn bush, a small stream bed, a cleft in the ground, etc. My point is that the closer the distance that two shield carrying warriors are with one another, the more they will be jostled around when one of them takes a small step too close to the other.
This might be an example of why the Greek hoplite armies repeatedly fought battle after battle against one another in the same wide open fields, such as Mantinea or Chaeronea. Also it might be an indicator of why the Romans might have abandoned their early usage with hoplite formations in exchange for the later manipular tactics. While the advent of the Manipular army is often dated to the loss against a tribe of Gauls at Allia, some ancient sources and modern historian believe the Romans developed some of their tactics after fighting in the hill country of the Apennines against the Samnites, which showed them further deficiencies in their tactics.
So, again, I reiterate that while I do not discount the use of a closed ranks formation in certain circumstances, such as defense against missile bearing enemy or to hold key terrain, as an offensive formation, it doesn't seem to be very deadly, just safe. WWCD? (what would caesar do?)
Anyway, food for thought.