Standardize Your Hose Couplings!

Standardize Your Hose Couplings!

How This Can Best Be Done—Great Progress of Work in Last Few Years—What Has Been Accomplished

NO real reform was ever accomplished without there first being a demand and a necessity for it. This is true of the remarkable work done in the standardization of fire hose couplings throughout the country. The following information, abstracted from the Bulletin issued by the Insurance Department of the Chamber of Commerce of the United States, shows graphically what has been achieved in this movement, and emphasizes the need that made this accomplishment possible:

A recent study of fires occurring in large cities of the United States discloses the interesting fact that one per cent of the total number of fires is responsible for sixtysix per cent of the total fire loss. Thus it is evident that primary consideration in community fire prevention effort should be directed toward those hazards or defects which might, under certain conditions, develop small fires into large ones and large fires into conflagrations. Fortunately, the United States has sustained relatively few mammoth conflagrations, although the potential danger of complete or partial destruction by fire is inherent to many American communities.

The conflagration hazard has been recognized in its true light by fire protection engineers and means have been devised by them to assist in preventing the rapid spread of fire throughout a community. It is not the purpose of this article to discuss the subject generally, but to point out one effective method involving little expense which would do much to insure the average American city the advantages of adequate fire protection in the event it is so unfortunate as to develop a fire of conflagration proportions.

Importance of Outside Assistance in Large Fires

The fire department of an urban community is very seldom of sufficient strength to cope successfully with a conflagration. As a result when such a large fire does occur, the first impulse of the fire department officials is to call for assistance from nearby cities. Such requests are always heeded and many record runs have been made by fire departments in answering summons for aid from cities threatened with destruction. Since motorized apparatus and paved highways are now in gen -eral use, the time necessary to make the run from one city to another has been greatly shortened and, consequently, outside assistance can be brought in within a comparatively short period of time.

Hazard of Non-Standard Hose Coupling Threads

Only too often, however, has this fine spirit of cooperation been nullified to a large extent because the outside apparatus has been unable to connect its fire hose couplings with the hydrants of the cities they come to save. With the development of municipal water systems, the installation of fire hydrants and the acquisition of pumpers by municipal fire departments each city seemed to have adopted a thread for its fire hose and hydrant couplings without regard to the thread used by other communities. Consequently, in the great Boston fire of 1872, the Baltimore conflagration of 1901 and the Augusta disaster of 1916, just to mention a few, the appaiatus which responded from the outside to the call for assistance was unable for the most part to be of any real service, clue to the fact that the couplings used on its hose and engines could not he connected with the local hydrants. Being thus without a water supply, pumping units which might have saved hundreds of thousands of dollars worth of property, were forced to remain out of action while the fire swept on.

Progress of Hose Thread Standardization. Standard Thread Used in Shaded Sections

The experiences of the past have settled beyond all doubt that a city or town having fire hose threads which are not interchangeable with those of its neighbors, is in constant jeopardy of serious losses in life and property values by fire. This has been recognized in some cjuarters for more than half a century as evidenced by the continued efforts which have been made to secure uniformity and standardization in fire hose threads.

Situation Prior to 1920

After the Boston fire of 1872 a thread somewhat coarser than the present National Standard was extensively adopted in Eastern Massachusetts. Other sections of the country, little realizing that they were dealing with a subject of country-wide importance, went at this problem independently. New York City selected a much smaller and finer thread which through more general use became a local standard in nearby New Jersey and New York State municipalities. Philadelphia, departing widely from the general practice, introduced a snap coupling which was afterwards brought into use by a number of cities and towns in that section of the country. Baltimore used a screw coupling of unusually large diameter and Washington the same as that in Eastern Massachusetts. The extreme West, following the precedent set by San Francisco, adopted an intermediate thread.

So it came about that not only in different sections of the country but in all the states and frequently in the same municipalities, there existed widely different and non-interchangeable threads. As a matter of fact today only five per cent of the cities and towns with non-standard equipment have a definite record of the thread which they are using. Two different sizes of threads are used in some cities while in one community four types are to be found.

Float Teaches Lesson of Proper Venting In the Safety Parade held in Baton Rouge, La., the fire department won second prize for their float which is illustrated. It was designed and constructed by Victor Charles, left, and E. B. Doiron. right. The display was mounted on a piece of reserve apparatus. The float was intended to convey the danger that lies in improper venting of gas heaters. Both Chief R. A. Bogan and his department feel very proud at having won the silver loving cup, the award as second prize.

The only logical solution for correcting this inexdisable situation was arrived at nearly 25 years ago by the National Fire Protection Association through its Committee on Hose Couplings and Hydrant Fittings, of which the late F. M. Griswold, Chief Inspector of the Home Insurance Company, was for ten years chairman. The coordination of efforts on the part of national fire fighting, water works, and fire protection associations, resulting in the adoption and widespread endorsement of the “National Standard Fire Hose Coupling Screw Thread,” was largely due to Mr. Griswold, and the notable achievements in recent years are a fitting memorial to the valuable service he rendered.

The chaotic conditions so long existing in the field were not materially improved, however, until the work of carrying on this standardization movement was taken up by the National Board of Fire Underwriters through its Committee on Fire Prevention and Engineering Standards. This latter organization is rendering an invaluable service through its close affiliations with the water utilities, fire departments, underwriters’ bureaus, state fire marshals, insurance departments, federal and local trade organizations, and national associations in securing a unity of action which is spreading the work of standardization to country-wide proportions.

National Standard Fire Hose Coupling Screw Thread

Early in 1924 sponsor organizations consisting of the American Society of Mechanical Engineers, the American Water Works Association, and the National Board of Fire Underwriters presented to the American Standards Association for adoption a standard setting up the manufacturing and inspection limits of coupling screw threads and developing a complete set of gage dimensions and tolerances. This standard had been prepared with the active cooperation of the National Screw Thread Commission, and received the approval of the American Standards Association in May, 1924. It is now known as “National (American) Standard Fire Hose Coupling Screw Thread.” This is an amplification of the standard adopted in 1907 by the National Fire Protection Association and subsequently by all the leading organizations interested. Pamphlets procurable from the American Society of Mechanical Engineers, 29 West ,59th Street, New York City, and the National Screw Thread Commission, U. S. Bureau of Standards, Washington, D. C, give the thread characteristics and limiting dimensions, with cuts of the threads and inspection gages, all in strict accordance with the best manufacturing practice.

Progress in Standardization

It was not until 1920, when through the initiative of the National Board of Fire Underwriters, Michigan and New Jersey first undertook to eliminate misfits in fire hose threads, that the correction of the existing field conditions may be said to have gotten under effective headway. With the continued assistance and helpful influence of sectional and state underwriting organizations, national associations, fire chiefs, state fire marshals and state fire commissioners, railroads, and other interests, this movement has since continued to attain increased headway.

At present thirty-five states are enrolled in this work of standardization. In the United States about 8,000 cities and towns have fire protection in the form of hydrants and fire hose. Of these over one-half now use the National (American) Standard Thread and of the remainder seven-eighths have threads that can be readily altered so as to be interchangeable with the standard. The work of conversion has now been successfully completed in about thirty cities of over 100,000 population, among which are Boston and Fall River, Massachusetts; Hartford and New Haven, Connecticut; Indianapolis, Indiana; Trenton, New Jersey; Washington, D. C.; Baltimore, Maryland; Kansas City, Missouri; Columbus and Youngstown, Ohio; Grand Rapids, Michigan; Memphis, Tennessee; Dallas and Fort Worth, Texas; and Seattle and Spokane, Washington. Legislative bodies in four of our states have passed bills making it mandatory that all public fire protection equipment shall be equipped with the National Standard 2 1/2. inch fire hose thread.

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Thus it is seen that after a half century of effort, the results obtained in a short period of eight years have brought the desired goal of nation-wide uniformity in the indispensable fire hose threads within comparative easy reach. The accompanying map which is reproduced through the courtesy of the American Society of Mechanical Engineers indicates the progress made in this field throughout the country.

Value of Standardized Couplings

In February, 1928, the city of Fall River, Mass., was threatened with complete destruction, by virtue of a fire originating in a group of mill buildings which were being dismantled. As the fire spread with great rapidity calls were sent to nearby cities for assistance. Twenty-four communities responded by sending 37 pieces of apparatus. Due to the standardization work which had been completed three years before in Fall River, the hose carried by all of this outside apparatus was connected directly to the Fall River hydrants or hose lines. With an adequate amount of working apparatus available the fire was brought under control after the destruction of parts of six blocks, as compared with the possible burning of the entire city which might have ensued without the outside assistance.

Another outstanding example of the value of standardized couplings was a call foe aid made by the Washington, D. C., Fire Department within recent months when an incendiary had, within a few minutes, set off several fires in the city which overtaxed the resources of the local fire department. Apparatus from Baltimore and other nearby towns arrived in a short time after being summoned and was ready to protect the city from further destruction. How different this was from the Baltimore fire of 1904 when Washington’s apparatus was helpless because it was impossible to connect with Baltimore’s hydrants!

A Field for Local Chambers

In any community in which the National Standard has not yet been adopted, the fire prevention committee of the local chamber of commerce may logically sponsor a movement to change the threads so that they will conform to the National Standard. This activity has been recognized in the Inter-Chamber Fire Waste Contest as one for which credit is given and consequently any committee doing work in this field will be given due recognition for it in the Contest. Inquiry on the part of the local committee will soon develop whether or not the municipality has adopted the National Standard Thread or soma so-called local standard. If the city is not safeguarded by the use of the standard the subject might be taken up with the municipal officials for the necessary authorization to get the work of conversion actually under way. The cost of standardizing the existing fittings in the average city is negligible.

How Standardization Can Best Be Accomplished

With the cooperation of the manufacturers complete sets of tools have been perfected for changing (by resizing and rechasing) the existing non-standard fitting so as to make them standard. Distributed throughout the country are about 100 sets of resizing tools, purchased largely by state supervisory organizations. In almost any locality arrangements could doubtless be made not only for the loan of a set of tools, but also for a demonstration.

The Insurance Department of the National Chamber will gladly assist any community interested in such a demonstration. Invitations to attend demonstrations should be sent to the municipal officials, heads of fire and water departments and representatives of civic bodies, not only in the city where the demonstration is being held, but in the neighboring communities that would be called upon to render aid in the event of a large spreading fire. Samples of the threads used in the several communities should be exhibited to show the existing variations and with the resizing and rechasing tools these samples should be made to conform to the National (American) Standard. Any local skepticism or indifference theretofore existing will thus be supplanted by enthusiastic support. Having obtained the tools and necessary authorization, it is then a matter of providing an experienced mechanic to supervise the work with the help of fire and water department mechanics, thus accomplishing standardization at a very small cost.


The final adoption of the National Standard Thread and the changing over of existing equipment to conformity with the standard will not alone insure for all time in the future the matching of the fire hose fittings of a community. This can only be accomplished through constant vigilance which begins with careful inspection of all the threads of each new lot of fire hose and fire hydrants as they are purchased. It is obvious that this inspection must be more than a casual examination of the threads and the screwing on of an old mating part to the new coupling or nipple. Hardened steel models or gages are available at moderate cost through the use of which newly purchased equipment may be tested before acceptance. Through this means absolute uniformity will be insured.

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