In N.M. Paterson & Sons, Limited v. City of Chicago (7th Cir. 1963), 324 F.2d 254, the seventh circuit court of appeals held that the district court erred in invoking the doctrine of comparative negligence in an admiralty action involving a collision between a steamer and a bridge. The court held that the equal-division rule should have been applied. That rule provides that even if the ship contributed two-thirds of the total fault, as opposed to one-third on the part of the City, the co-defendants would have to divide the damages.