“一年战争”后期,联邦军军力不足,由 于刚开发的RGM-79“吉姆”数量不可能满 足前线的需要,为了在短时间内赶上自护的战 力,联邦军决定在宇宙施工机械“SP-W03” 上追加装甲及武器,并将其改造成小型机动堡 垒“铁球”。机体上只装备了一门“RX-75”用 120毫米低后座力加农炮。“铁球”作战能力极 为低下,但是与RGM-79“吉姆”协同作战 时的效果相当不错,又因为制造成本相当低 廉,所以联邦军将“铁球”大量生产并配备了 In the latter part of the Year of the War, the military strength of the Confederation was insufficient. As the number of newly developed RGM-79 / Jim could not meet the needs of the frontline, in order to catch up with the self-care ability in a short period of time, the Federal Army decided Add armor and weapons to Cosmic Construction Machinery “SP-W03 ” and transform it into a mini-motorized fortress “iron ball”. The body is equipped with only one “RX-75” with 120 mm low recoil cannon. “Iron Ball ” very low combat capability, but when the RGM-79 “Jim ” the effect is quite good, and because the manufacturing cost is very low, so the federal army will “iron ball ” mass-produced and equipped It’s