The tactical hard choice facing the defence of Grey Crag was a straightforward problem of artillery range asymmetry.
In the Citadel planning room, Giles Croft drew two nested circles on the thick parchment range chart with a pair of brass dividers.
“Grand Duke Val-Khorne’s balance weight trebuchets represent a specific tactical threat envelope,” Giles explained to Captain Kenneth Drake, Master Borin Bronze-Lung, and Garrick Holt. “A medieval balance weight trebuchet with an eight-ton balance weight box accelerates a three-hundred-pound dressed granite projectile across an effective maximum range of four hundred yards.”
Kenneth Drake tapped his iron-shod pacing rod against the timber floor, his brow furrowed.
“Four hundred yards is outside the reach of our defensive wall giant crossbows, my lord,” Kenneth said.
“Our heavy steel crossbows and twisting force catapults drop their bolts at three hundred yards. If the Duke establishes his siege park behind timber mantlets three hundred and fifty yards from our railhead, he can pound our trackbed, shatter our concrete abutments, and breach our defenses while leftover fully immune to return fire.”
Giles adjusted his dividers, expanding the legs until they spanned the entire outer valley.
“He’s immune only if we accept his weapon shape,” Giles said.
