There is a difference of opinion as to the efficiency of flushing by hose. In Philadelphia all alleys and streets whose width between curbs is too narrow to permit the use of street brooms are cleaned once each week with hose. When additional cleaning is necessary it is done with hand brooms.
Very says that hose flushing is ineffective and uneconomical, and that water does not reach the pavement in such manner as to give full effect and usually is doing no work at all.
One city report makes this comment: “Four or five sweepers hold a hose and play it in some sections as though the object were to wash away the asphalt block pavement and car tracks. Target shooting, with a stream of water, so-called flushing, will never supplant wetting and scrubbing.”
Very also claims that water to be effective must reach the pavement surface in a chisel shape and at a proper angle to remove and carry off the filth. He says that no man is properly constructed to hold the hose at a proper angle with the pavement to obtain the best results for any length of time. Commissioner Fetherston says New York’s experience shows that a hose gang consisting of two men is able to clean well from 23,000 to 25,000 square yards of the dirtiest Belgian block pavement in eight hours, and will clean upward of 30,000 square yards of smooth pavement of modern granite block in the same time, using 2-inch hose, which is that city’s standard size for use with its new hose reels. The amount of water required to clean 1,000 square yards is approximately 1,000 gallons.
Cleaning by Squeegeeing
The squeegee method is used on smooth pavements. Batteries of two and three squeegees are usually preceded by sprinklers, which use as much water as possible without flooding the pavement, while the squeegees use just enough water to create a wash. The idea of sprinkling the pavement is to soften the surface and enable the squeegee to cleanse the street of slime as well as coarser material. Squeegees are followed by men who sweep up windrows of dirt into piles and a sufficient number of carts follow to remove the dirt. In New York where no sprinkling cart is used they average 50,000 square yards per machine per day with the use of 200 gallons of water per one thousand square yards. In Washington with a sprinkling cart they get about 80,000 square yards per machine per day.
Parlin says that squeegeeing produces very effective results with a limited use of water on smooth pavements in good repair.
Very believes that squeegee machines have their value, and if the sprinkler cart is used in advance better results are obtained.
In Milwaukee machines are in constant operation on smooth surface pavements. In certain sections where streets are exceptionally wide, three machines are used in staggered formation and necessitate but one and one-half complete trips over a street to perfect cleaning. They are routed in such a manner that little idle travel is necessary and filling plugs are specified to prevent empty haul to any great extent. The same system is applied to territories where only two machines can be operated, except that four return trips are necessary to complete the work. In no wise are operators allowed to confine their work within a given block unless conditions prevent, but must continue until tanks are emptied, which usually occurs at end of second block. Two laborers are employed with these machines to keep gutters free from dirt and obstructing the water from flowing to the catch basins.
The average area cleaned in one year was 377,712 square yards at a cost of $96.35 per day or 25.5 cents per 1,000 square yards. Of the total yardage of pavement in the city 1,105,324 square yards are free from car tracks and subject to squeegee process. Some are squeegeed twice a week while others are cleaned but once and each have the additional service of White Wings and sprinkler.