Thread:Shas'o'Kais/@comment-5880884-20121225092851/@comment-3580035-20121226110106

Tau Energy shields work differently to Imperial Void Shields in that they don't absorb incoming fire, but rather seek to deflect as much force away, or spread it out over the wider surface area of the field (based on inference from various Tau sources of Tau spacecraft). Blasts can still penetrate the shield though, but this won't collapse the shield itself unless the shield generators are damaged (again, based on inference; this can prove entirely false).

The Apocalypse expansion, though, represents Energy shields in the rules by using a set invulnerable save rather than the standard void shield rules; which is the biggest clue. The rules in Battlefleet Gothic, however, are simplified to make gameplay easier (as I don't think there is anything similar to a armour/invulnerable save equivalent rule in BFG). Also, Battlefleet Gothic is somewhat outdated in terms of timeline (as it uses the old Tau ships) and also only featrues Mantas in the fleet lists as escorts without complete rules/fluff for them.

However, it would help if you can help clarify the rules for void shields in BFG as I only have the Tau section of the book and I'm not familar with BFG's gameplay. If they state that shields do collapse and can be raised again on spacecraft, then it may be a error. As the Manta is more akin to a Titan-level construct, however, I am merely basing my comparisons around that level of shielding, that is; Manta energy shields and Titan Void Shields.