Board Thread:Warhammer 40k General Discussion/@comment-4851119-20140719123726/@comment-86.174.92.43-20160501201318

Battle of Macragge - The Ultramarines and allied units including fleet assets defended Macragge successfully. This was a large hive fleet and a large but not massive defence force. They were massively aided by detonating the warp core of a battle ship in the path of the hive fleet, destroying a large chunk of it.

This is not too dissimilar to the use of burning ships used by the English against the Spannish Armarda.

If I were looking to defend against a hive fleet, I would draw from long term moth balling, older ships of the line and using scout units, plot the path of the Hive fleet. I'd then drift the striped vessel into the paths. Drifting would have the added benefits of not been anywhere near as noticable (running cold, dark and silent...) as a 'live ship'. Recon in force would active the drift fleet, presenting enough of a target to draw enemies into the kill zones and cut down enemies numbers, without the abilty to recoup their losses, with (relatively) minimal blue force units.

Use of drift attacks was documented in several sources, including the Sons Of Horus attack on the orbital defences before the battle of Molech. So it should be known to the battle commanders.

You also have the benefit of reduced fallout/risk of at ground level, compared to use of tactical nuclear, chemical or biological weapons.

Regarding exterminus grade weapons, fairly sure that one of the sins of the Astral Claws was to build and stock pile more than they should. So I have a feeling they are able to be made, maybe just not as easily as we want but still useable.