Oiled Roads (2)
The initial cost of park and boulevard work in purchase, shaping, grading, planting, building of drives and so forth is a heavy one and the average taxpayer feels when that is settled he has paid it all. But the cost of maintenance is never ended. And after all, it is the efficiency of maintenance of the work completed that makes friends and fosters park and boulevard sentiment. A good, smooth road, neither dusty nor muddy, we must have at all times.
How can we best accomplish this result?
It is believed that through liberal use of oil on well-built macadam roads a step forward has been taken, securing thereby not only the most economical but also the most satisfactory dustless drive.
In our early experimental days with oil we had public opinion against us. One didn't need to keep an ear very close to the ground to know how the people felt about it. They didn't want it and they didn't hesitate to tell us so. Our files show letters and petitions asking us not to put that "nasty oil" on the boulevards, followed later by ones from the same people asking for it. Today you would have to search diligently in Kansas City to find opponents to our use of oil on the roads. Like the original "park kickers" they, too, have passed away, passed away even beyond the confines of our county, for the farmers know a good thing when, they see it and are demanding oiled roads, so that when they come to the city with wagon loads of produce or with their families in their automobiles, it is not to travel in a cloud of dust but to make a pleasant journey over smooth, dry, dustless roads. Our county commissioners show that they are progressive and up to date in giving to their rock roads the treatment of oil.
Until last year we sprinkled with water, which we found cost us approximately two and one-half cents per square yard, over $14,000 a year and this meant either mud or dust, often both at the same time. Complaints were numerous. Sprinkling with water did not give us satisfactory roads. We wanted something better. Our landscape engineer, Mr. Kessler, endorsed and advised the use of oil.
In the fall of 1906, our first experiment was made with light residuum oil. This not only proved of value as a dust layer, but as a protection to the macadam from water through the winter and spring months.
The test was so satisfactory that our president, Mr. Hudson, who is and has been an oil advocate from the first, together with our superintendent, Mr. Dunn, not only talked oil but early in the spring of 1907 got out and hustled for the best and most available road oil. In this rich empire of the West, it is not necessary to go far from home to find anything you want. If it's not on the surface, our rule is to dig down and find it. Over in Kansas they found and contracted for heavy oil at eighty cents per barrel of forty-two gallons, f. o. b. Kansas City and this is the oil we are still using. It is not the crude oil as it comes from the wells, as our crude oil has but little value as road oil. It is a residuum from which the distillates naphtha and kerosene have been removed and has a paraffin base.
In Los Angeles they have native oil with asphaltic base which they use direct from the wells. Oil with asphaltic base is a better road oil than one with a paraffin base. Our oil has a specific gravity of 20 to 21 Baume.
Oils and other substances which are lighter than water are referred to reading on the Baume hydrometer. This is an instrument used in technical work to obtain relative specific gravity. Distilled water is used as a standard and its reading is ten on the hydrometer. The heavier the oil is, the closer it approximates to ten, all readings being kept at a constant temperature, 15°C or 60° F. Our oils were at first all tested by the city chemist, but as his reports were of little value, owing to scientific statements contained, we finally purchased a hydrometer and make our own tests for specific gravity.
For the advantageous handling of oil we put in a switch track on the Belt Railway and built two steel receiving tanks of 8,000 gallons capacity each at a cost of $715. These tanks were built at such an elevation as would permit of unloading from tank cars into them by gravity, thence into sprinkling carts by same method.
In 1907, beginning in May, our entire system of macadam roads was treated with an application of oil and during that year most of them were given two applications. We used thirty-three cars of oil and the cost, including oil and labor, was $10,671.44, or about two-thirds as much as the old method of sprinkling with water. The results were in every way more satisfactory. It gave us dustless roads, impervious to water and held in place the finer material as cover to the macadam, which, under the sprinkling with water practice, was torn loose by automobiles and washed into the gutters by rain and sprinkling, or blown away by the wind as dust.
No water from rain or snow penetrates the oiled surface and the road is dry as soon as the rain ceases or the snow melts. The freezing and thawing of the winter and spring breaks the surface but little.
The first application of oil to a road is the most expensive. More care and work are required to prepare the street and more oil is used. In the first application, the oil penetrates further than in subsequent ones. We figure the cost of the first treatment at one and one-half cents per square yard, against one cent per yard for later applications. One gallon of oil covers from three to four square yards of surface.
Before applying, the road should be swept as clean as possible to insure better contact and penetration and to lessen its picking up. For this we use the ordinary rotary street broom, although it can be done as well with the hand push broom. The sweepings are left along the edge of the gutter to protect the cement work from the oil.
Oiling a road is dirty work, and. care must be taken to protect the crossing to the public, keep the workmen from tracking up the cement work, and to preserve and restore the street as quickly as possible. To do this, the best practice is to barricade one-half of the street in the block to be oiled, before any oil is spread. As soon as the half block is oiled and broomed until there are no bare spots or pools of oil, the sweepings along the gutter, together with sufficient limestone screenings to form all absorbent, should be flirted over the freshly oiled surface. It is good practice to follow this dressing with a light road roller, especially if the travel over the road is light. Where there is much travel, the rolling is not so essential and we do not always do it, but open the street at once. The other half of the street may then be treated immediately in the same manner, or left for some more convenient time.
The pavement should of course be dry, as oil and water just won't mix, and the hotter the pavement, the better. In cool weather we find it necessary to heat the oil so it will flow freely. For this purpose we have each of our receiving tanks piped with ¾ inch steam pipe from a four horse-power boiler, purchased for that purpose at a cost of $67.50. This is set up close to the tanks and enclosed in a knock down boiler house. When, as it often happens, the oil stands in the sprinkling cart over night and is too heavy to flow well, we heat it in the cart with a steam hose from a road roller. My advice would be, always heat the oil; it penetrates better, picks up less and covers more.
For distributing the oil on the road, we use the ordinary street sprinkler, discharging the oil into a perforated tin trough under the outlet valves, which is hung parallel to the wagon axle. This trough is about seven feet long, six inches wide and six inches deep. The size of the perforations depends on the kind of oil used. One-quarter inch holes about one and one-half inches apart serve for such oil as ours. This simple contrivance works very satisfactorily.
We feel that if we had an oil of asphaltic base available for our use, it would do away with one objectionable feature on heavy grades. That is, a tendency to become slippery. We are making experiments now and expect to keep at it until we are able to overcome that condition. It may interest you to know what we are doing, but as we only began these tests last Saturday it is too early yet to discuss results: Our first experiment was made on a block of new macadam on Valentine Road, between Wyoming Avenue and Genessee Street. Our second on old macadam on Broadway near 31st Street, by using a mixture of Utah asphalt, known here as "Sarco" with residuum oil, the proportion of "Sarco" being about ten percent. To get a mixture of these two, we have had built an open top steel heating tank, holding 250 gallons, with a fire box underneath and mounted on low trucks, with a short handle attached.
The asphalt is first put in and heated until it is thin. The oil is then added and thoroughly stirred, while the heating is continued. The tank is built with a vertical paddle rod or mixer in the centre, having a geared crank shaft with a handle for turning by hand. When hot and well mixed, we spread it from buckets.
As you see, we are yet in an experimental stage in the use of oil on macadam roads and we are doing things in a crude way. We hope and expect to arrive at better methods and better results from its continued use, such as a cheaper cost of succeeding applications with a longer life of road and smaller cost of maintenance.
In appearance, the roads will speak for themselves, and you are to form your own opinions of them.
From the publication:
AACS - Proceedings of the 22nd Annual Convention
Held at Kansas City, MO
August 11, 12 and 13, 1908