[split] Phalanx warfare: use of the spear

[Dan Howard]

2cm thickness? that would make it quite heavy i suppose..

Which is why people went to the trouble and expense of using metal. Any other material that provides similar protection is considerably thicker and heavier.

any tests been made against such armor?

I can't think of any that have been published.

but was it actually doubled?

It is doubled on the upper chest, which, when in formation, seems to be vulnerable to a spear thrust angled from above.