Fire Risk and Insurance. When reinforced concrete first came to the front for factories and warehouses, the insurance companies hesitated to assume such buildings as first-class risks. However, examination and tests have gradually convinced the most skeptical of their true fire resistance, until now structures of this material are sought after and given the lowest rates of insurance.
Mr. L. H. Kunhardt, Vice-President and En gineer of one of the oldest of the factory mu tual insurance companies—which have for years played a leading part in the development of mill construction and of the science of fire protection engineering and the consequent reduction of fire losses—presents very instructive figures com paring the costs of insurance upon several types of factories for various classes of manufacture. Mr. Kunhardt also indicates the means by which concrete may be utilized in reducing even the present low rates of insurance upon buildings protected by efficient fire apparatus.
From the statements there given, we may conclude that a well-designed reinforced factory with continuous floors (1) offers security against disastrous fires and total loss of structure; (2) reduces danger to contents by preventing the spread of a fire (3) prevents damage by water from story to story; (4) makes sprinklers un necessary in buildings whose contents are not inflammable; (5) reduces danger of panic and loss of life among employees in case of fire.
Mr. Kunhardt says : "In consideration of the question of insurance on reinforced concrete factories, the problem simply resolves itself into a determination of what the fire and water damage will be in the event of fire, compared with that in other types of factory buildings.
"For this purpose concrete factories may be divided into two classes : "(1) Those having contents which are not inflam mable or readily combustible. In this class, if wooden window-frames and partitions, etc., have been eliminated, the building as a whole becomes practically proof against fire, provided there are no outside exposures, protection against which would require special precautions.
" (2) Those having contents which are more or less combustible, and which have in their construction small amounts of inflammable material, such as wooden win dow-frames and top floors. In this class the burning of contents is the cause of damage to the building, the extent of which is determined by the character of the contents.
"Of the two, the latter class is the one ordinarily met, and with which the question of insurance cost is there fore usually concerned. The character of the occupancy, details of construction, and conditions of various kinds inside and outside the factory, and in the various com munities, have such direct bearing on rates that any statement as in Table IX of comparative cost must be extremely approximate, but perhaps of value as showing somewhat the relative costs. The costs are estimated upon the basis of a building without a standard fire equipment, which condition is, however, now rare in the case of first-class factories and warehouses, even if of fireproof construction.
"Table IX illustrates in a general way the gain by the use of the better type of construction; but in factory work, it has long been recognized that there is a distinct hazard in the manufacturing operations and infiammablc contents, which is greater in degree than in other classes of property. The science of fire protection with auto matic sprinklers and auxiliary apparatus has therefore attained such a degree of perfection that the brick or stone factory with heavy plank and timber floors is ob taining insurance at rates which are lower than those that are possible on any of the fireproof buildings with out sprinklers. The real reason for this lies in the fact that the contents, including machinery, stock in process, and finished goods, constitute by far the larger part of the value of the plant; and these the building alone can not be expected to protect when a fire occurs within, except in so far as the absence of combustible material in construction may assist in so doing. Fire protection is therefore needed for safety of contents, even if the build ing itself is practically fireproof.
"As illustrating the value of fire protection, I would state that in the Boston Manufacturers' Mutual Fire In surance Company, and others of the older of the Factory Mutual companies, the average cost of insurance on the better class of protected factories has now for some years averaged, excluding interest, less than seven cents on each one hundred dollars of risk taken; and on first class warehouses connected with them, one-half this amount. These figures can be compared with the table as illustrating the gain by the installation of proper safe guards for preventing and extinguishing fire.