The Value of Iron Building Construction.
Under the above heading, Firemaster Fred. Lenz publishes a timely article on the subject in his Der Nord-Deutsche Feuerwehrmann. He says that for a number of years it has been pointed out by professional firemen that the favorite iron constructions are only to a small extent fireproof. Nor do the highly vaunted and solid-looking granite constructions, especially for staircase wells or shafts, possess that reliability with which they are accredited. The writer mentions having seen such a “thoroughly substantial” staircase shaft or tower, which suffered only by the licking flames at the entrance doors, crumble and fall together. Every fire brigade of any experience will know that it is a mistaken idea to regard iron of itself as a fireproof material. The T bearers and columns not provided with an isolating protection very seriously endanger the part of the edifice lying either above or adjacent to them by their expansion or bending. It would be excellent to remember this fact when, as is at present so often the case, ground floors are altered or rebuilt into stores and the stories lying above them are left, as it were, suspended in the air. Architects have, during the past too years, found various fireproof, or almost fireproof, building materials, especially for staircase shaft. Recently a house carpenter publicly instituted a fire test for ascertaining the reliability of staircase constructions. For this purpose he erected two staircases. One of the two was of iron with perforated steps ; the steps of the other were covered with sheet iron, upon which lay wooden boards. (Unhappily, the foregoing description is rather vague in the original, but the translator has rendered it to the best of his understanding, viz., that one pair of stairs were iron, the other wood; the footboards of the latter were covered with sheet-iron over which other wooden boards were placed.— Trans/.) A large quantity of wood heaped under the two different stairs was then set on fire, but in spite of the very intense fire the wooden stairs remained entirely uninjured. About fifty minutes after the starting of the fire, and when the iron staircase was red hot and had lost all shape, a young man had the temerity to mount the composite staircase.
“ In conclusion,” says Mr. Lenz, “ it is my experience that an old oaken staircase house can stand an exposure to the licking flame for at least fifteen minutes, sometimes thirty, without catching fire, even if unprotected by any kind of cement or other favorable conditions. It is well, therefore, not to attach too much value to iron, and not to trust it by using it for fire quenching and life-saving apparatus.”