ARMY WATER PURIFICATION UNITS
Motor Driven Water Trucks for Chlorinating and Filtering the Supply for the A. E. F.— Experimentation Did Not Affect Basic Principles of DesignDescription of the Unit
THE World War brought forth many novel developments in every line of endeavor, and, although the water supply field was but one of many, it is pleasing to present before this convention of water works men, a discussion of the units developed and manufactured in this country, by members of this association, to be operated in France, and elsewhere, by other members engaged in delivering safe water supplies to our military forces. The portable motor truck mounted water purification units about to be described present nothing new in the fundamental principles of water purification, but show the applicability of the principles used in stationary domestic plants, to portable plants for military use.
In 1914, the necessity for a specially organized water service was not recognized by any of the allied forces, water supply functions being the duty of engineering troops. The purity of the water was determined by the medical department. The water supply conditions presented in France and in Belgium, and the problems of water supply met in trench warfare, were entirely different from problems presented in previous wars. The soils of Northern France and Belgium were for the most part highly cultivated, fertilized for scores of years with night soil.” and other refuse, so that water supplies normally obtained in the battle area were highly polluted. Then, too, the German forces in passing over the country indescribably polluted all water left behind when retreating, making special measures necessary for purification.
It is reliably reported that the 1915 Champaign Campaign of the French army broke down largely due to the inadequacy of water supply arrangements, and at the close of this campaign, the French war office organized a special water service for the second French army, under the direction of Major Bunau-Yarilla, well known through his endeavors to construct the Panama Canal with French financial support.
Chlorination of All Water Supplies by French
The chlorination of all water supplies used for drinking and cooking purposes was required by the French Military authorities. Calcium hypochlorite, or sodium hypochlorite, was applied in such quantities that fifteen minutes after treatment, there remained two-tenths parts per million of residual chlorine. It should be pointed out that such excessive amounts of residual chlorine, greatly in excess of American practice, left objectionable tastes and odors in the treated water, so that the troops were apt to take the more palatable, but dangerous, untreated water from flowing streams, shell holes and the like, when possible.
*Excerpts from a paper prepared for the annual convention of the American Water Works Association, at Buffalo, on June 9-11, 1919.
American Water Supply Regiment
The United States forces in entering the conflict, taking advantage of the lessons learned by the Allied forces, created a water supply regiment, the 26th Engineers, which was officered by experienced water works men, most of whom are members of the American Water Works Association. This regiment had charge of the water supply of the American forces, both in the advance area, and in the rear. Early in the war, the need for portable water wagons for the purification of supplies was presented, and bulky equipment with filters and devices for treating the water with hypochlorite were put forth. In 1916 the availability of apparatus of American manufacture to control liquid chlorine made possible the first efficient motor truck mounted water purification unit.
First Unit Gives Satisfactory Results
When this country entered the war, we believed that the experience we had gained through co-operation with our British house in construction of equipment for the British forces, should be placed at the disposal of the military authorities. With this in view, equipment based on the British unit, but modifying the typically English characteristics to introduce American methods and equipment, was constructed and tested under varying conditions at Maplewood, N. J. Water was taken from the west branch of the Rahway River, a grossly polluted stream. This first unit was equipped with rotary pumps, which did not prove suitable, and subsequent units were equipped with gasoline operated force pumps.
Various members of this association, who were officers in the Engineer Corps, or in the Sanitary Corps of the army, offered helpful suggestions and contributions toward the development of this unit, which, when placed in operation, gave highly satisfactory results.
Separate water analytical laboratory trucks were contemplated, and it was ultimately concluded to modify the design to permit the incorporation of suitable laboratory equipment. By building a separate room in front of the truck, using small cylindrical tanks for contact and storage chambers, and placing these tanks under the laboratory benches, a marked saving in the space required was effected.
Description of Operation
The water is pumped through a fifty-foot suction line of two-inch steel-woven suction hose fitted with bronze check valve and strainer, by the gasoline engine operated pump, located at the rear of the body. A very heavy dose of chlorine is applied in the pump suction, from a manually operated solution feed chlorinator, located on the rear wall of the laboratory room. When waters o low alkalinity are treated, soda ash is applied with the chlorine solution into the pump suction. Passing through the pump, with a relief valve set to operate at fifty pounds pressure, the water is passed to a specially designed pressure filter, being treated with alum through the standard dash-pot arrangement en route.
From the filter the water passes through an inch and a half water meter, thence through a diaphragm pressure regulating valve, to maintain constant back pressure on the chlorinator water supply line, thence through the storage and contact tanks located beneath the laboratory benches, to the point of discharge at the forward left hand corner of the truck. Just at the point of discharge, the water is treated with sodium thiosu’phate solution regulated and controlled by a special dechlorinating equipment.
Absolutely Sterile Water at Point of Discharge
These units were designed, having in mind the grossly polluted and befouled waters that would have to be treated and. based on the British practice and experience, high doses of chlorine were introduced into the raw water. The filters served to clarify the water, and at the trial tests, absolutely sterile water was obtained at the point of discharge.
It was thought necessary to make provision for removing the excessive residual chlorine that would be in the water after passing through the contact tanks, and a proportional pressure feeding thiosulphate dosing device was developed. It should be mentioned that provision for dechlorinating was made in accordance with the British experience, who used the process of dechlorination by the application of compressed sulphur dioxide gas in all their portable units. On the British trucks the sulphur dioxide was controlled by a standard direct feed manually controlled chlorinator, of American manufacture.
In the American truck, the chlorinator used was of the standard manually controlled solution feed type. Control valves for the soda ash and thiosulphate solutions were in the rear of the laboratory below the chlorinator so that all chemical application should be centrally controlled by the laboratory operator.
The first several trucks were constructed with horizontal pumps, and it was found that special provision was required to eliminate excessive vibration in the laboratory. With this in view special spring supports were developed. On the later trucks a vertical force pump was used, and this so eliminated the vibration as to obviate the necessity of special spring supports.
Modification, But no Change in Basic Principles
The development, construction and testing of the first lot of trucks, and the tests and recommendations of the Board of Inspecting Officers, representing the office of the chief of engineers, the engineering depot, and the Sanitary Corps of the army, resulted in many modifications of design and rearrangement of equipment, but not in any change in the basic principles involved.
The value of these units became so apparent that increased facilities were required for their manufacture. An admirable factory in Camden, N. J., was obtained, and herein conjunction with our construction work, a school for Sanitary Corps men, members of the water tank train, and officers who were to have charge of the trucks in operation, was conducted.
Fig. 1 shows the complete details of the unit, as finally developed, both plan and elevation.
Fig. 2 indicates the rear of the completed truck, with the rear and side gates let down for operation, showing the gasoline storage tank to the right of the pump, and provisions made for carrying and chaining the suction hose. The filter, central control valve for operating the filter, soda ash solution tank, alum pot, dechlorinator, etc., and further details of the pumping room are indicated in Fig. 1.
In Fig. 1 may be seen in the upper right hand corner, a tool box in which a complete set of pipe cutting and fitting tools are kept in addition to hand tools needed about a machine shop, and beneath this tool case is the chemical bin, for storing alum soda ash, and thiosulphate.
Laboratory Arrangement of Final Truck
The laboratory arrangement in the final truck is shown in Figs. 3 and 4. The provision made for carrying chemical bottles is indicated, as is also the sink for washing glassware, and a hand air pump for creating pressure in the storage tanks when the pumping equipment is not in operation. A 37 degree incubator for bacteriological samples, oven for sterilizing glassware, and electric lighting equipment, are illustrated, while in the rear of the laboratory is shown a standard solution feed chlorinator, and beneath it the thiosulphate and soda ash controls. On the bench beside the chlorinator is a pressure auto clave for sterilizing purposes.
On the first page cover of this issue is shown one of the trucks in operation at Cooper Creek, Camden, N. J. The very best materials available were used in the construction and assembly of the units. The first several trucks were mounted on three and one-half-ton White truck chassis, but by far the largest number were mounted on five-ton seventeen-foot wheel base PierceArrow chassis. Novo three-horsepower gasoline engines were used^ with Gould five-inch by five-inch force pumps. The filter was constructed by the Roberts Filter Manufacturing Company; the electric lighting equipment by the Vesta Storage Battery Company. The rated capacity of the unit was 1,000 gallons per hour, although the actual delivery was nearer 1,500 gallons.
Support of Filter a Problem
The support of the filter, which weighed 2,400 pounds without the water, presented problems that required careful study. The final solution was to fasten fiveinch steel H beams to the chassis frame by U bolts, bolting the filter to the H beams by feet cast on the special filter base.
In addition to the equipment shown in the drawings, 1,031 articles were carried. Still, much to our dismay, when the trucks were first placed in operation, we found that we had overlooked the very obvious item of a box ot matches, These units rendered valuable service under actual military operation in France. Some of them were injured by shell-fire and some of the Sanitary Corps men were wounded in operating the units near the firing line.
Acknowledgement must be made of our appreciation of the co-operation extended by the surgeon general’s office, the Sanitary Corps, the office of the chief of engineers of the army, the engineer depot and particularly to the following officers: Colonel F. F. Longley, Lieutenant-Colonel Edward Bartow, Major H. McC. Yost, Captain Morris ScharfT, Captain Gerald W. Knight, Captain W. F. Wells, Captain J. J. Newmann, Lieutenant A. H. Wagner, Lieutenant H. H. Scott, Lieutenant T. W. Smith.
Without the suggestions and co-operation of Mr. M. F. Tiernan and Mr. C. F. Wallace, of our organization, these units could not have been constructed, and special thanks are due to two members of our staff, now in service in France—Captain A. R. Murphy, who materially contributed to the development of the first unit in the tests at Maplewood, N. J., and Captain R. V. Donnelly, who was in charge of their construction at Camden, N. J.
Thanks are also due to the engineers of the Roberts Filter Manufacturing Company for their especial cooperation.
The Board of Water Commissioners, of Holyoke, Mass., has under consideration petitions for salary increases from