In any existing grain elevator, malt house or similar building, the exterior walls of the marine tower, which is defined as that part of the structure in which is located the machinery for conveying grain from boats to the conveying bridge, and thence to the bins; and the exterior walls of cupolas and conveyor bridge, which is that part of the structure housing the conveying and elevating machinery above the fireproof bins, may, if the same require replacement, be replaced with galvanized corrugated steel, protected metal or asbestos corrugated material fastened to the steel structure by rust-proof bolts.
(Prior code § 92-105)