Part 3 (1/2)
ROAD CONSTRUCTION
The question of the kind of road for hauling logs with the motor truck is a very important one. It is impossible to move a fifteen-ton load day in and day out unless there are good roads, and no motor truck operation of reasonably large proportions can be successfully maintained without a road that is well constructed and which will not give way during any kind of weather, under the loads that are carried. One cannot successfully and continuously operate on dirt or even gravel roads as they are good only when dry. Good roads are as important to the motor truck operator as the railroad is to the transportation of logs by rail.
The big handicap in motor truck logging in the past has been poor roads.
The same man who will survey, grade, carefully lay and ballast the steel for a logging railroad will many times put a truck and trailer on a poor dirt road and expect the truck to haul economically and satisfactorily.
A motor truck will haul over some mighty poor apologies for roads but it does not pay. A good road is an excellent investment. It makes larger loads and more trips a day possible, will save on tires and repairs, and will require less gasoline to the mile; the efficiency and output will be increased and the time and operating costs will be decreased.
[Ill.u.s.tration: Sub-grade for motor truck logging road.]
There have been some very successful operators who have secured a small body of timber at a low price on a public road who made the motor truck pay without building a road. This method of logging in a small way will continue to be carried on by small operators who will haul only during three seasons of the year or even less. However, the big future for the motor truck for logging is in the larger tracts of timber where it would not pay to put in a railroad but where a good type of motor truck road can be built cheaply and loads as large as the truck can handle be carried with no road restrictions as to the weight.
In general four types of roads are used by loggers: (1) the cross-plank road, (2) the fore and aft pole road, (3) the fore and aft plank road, and (4) the cement road. The puncheon road is a modification of the fore and aft plank road and will be taken up with the latter. The methods and cost of construction, the advantages and the disadvantages of these various types of roads follow in detail.
_Sub-Grade_: The sub-grade is put in the same way for each type of road.
The average width of the truck is seven feet and six inches, calling for a road about eight and a half feet wide, so that the sub-grade should be twelve feet in width. An ill.u.s.tration of the amount of grading necessary is shown on page 25. Too much care cannot be taken in the matter of ditches for draining. In a rainy climate, the water should be carried away from the hill side of the grade every fifty feet.
_Cross-Plank Road_: The cross-plank road is constructed by laying cull ties on hewn poles lengthwise of the road. Three rows, four feet apart are used and second grade ten foot plank, six inches thick and of random widths, are securely nailed to the ties. Great care must be taken to have the ties laid fairly smooth if the road is to be even. Plank less than six inches in thickness should not be used as the thinner ones very soon crack and go to piece under the excessive jar and vibration.
This is a very expensive road to build as it wastes material. Six thousand feet of lumber is necessary for every hundred foot station, at a cost of $222 a station for the material alone, without considering the cost of laying it. The maintenance cost also is very heavy because the nails pull out as a result of the vibration caused by the truck. This type of road is used only over short stretches, such as swampy ground in connection with the dirt road, and on steep grades and sharp turns in connection with the pole or plank road.
The Esary Logging Company at Camano Island, Was.h.i.+ngton, put in a cross-plank road for a short distance on a sharp curve and a steep grade, to see how it would affect the traction. It was found that cross planking was not necessary on curves where the grade is ten per cent or less when coming down with a load, providing trailer brakes are used. In the future the company will not use this type of road unless grades above this maximum are encountered. It is impossible to lay a cross-plank road smoothly because the stringers settle and make the road b.u.mpy. The resulting jar on the equipment and the fact that these stretches have to be taken at a much reduced speed, furnish ample reason to condemn its use.
The only real use for a cross-plank road is to secure better traction on grades exceeding ten or twelve per cent, and then it should be laid with a s.p.a.ce of about one inch between the planks. Even in such cases it would be better to use some other method for securing traction, such as sanding the track or winding the drive wheels with a light cable. The waste of material and the excessive vibration limit the use of this type of road.
_Fore and Aft Pole Road._ In the fore and aft pole road, poles from twelve to fourteen inches in diameter are hewn on one or more faces and laid longitudinally with the road, with one or more logs for each wheel track. This type of road is commonly used by motor truck loggers and is one that lends itself readily to their use. It is the most practical road that can be built unless there is a small saw-mill handy to saw planks for the fore and aft plank road. The smaller material growing along the right of way is used at an expense of only what it costs to fell it, hew it and put the poles in place. Hemlock poles may be used to advantage.
Some operators use the single large pole placed on cross-ties eight or ten feet apart and use lighter eight-inch poles placed on the outside for a guard rail to keep the truck from leaving the track. The main pole is laid in a ditch about eight inches deep, leaving it half buried. This helps to keep the poles from spreading and increases their firmness and strength. The pole is notched into the cross-ties, which are made of logs not less than eight inches in diameter, and is securely nailed or bolted to prevent it from rolling. The outside guard rail is laid on the surface of the ground close to the main track and is securely braced from the outside by means of posts sunk into the ground or it may be spiked to the main pole or to the ties. When running with the trailer on this narrow type of road, the guard rail is very necessary.
After the poles have been laid, the sub-grade should be ditched in the center deep enough to carry away the water that falls in the middle of the road. The success of the road depends to a large extent upon good drainage.
The Meicklejohn and Brown Logging Company near Monroe, Was.h.i.+ngton, operate over a pole road with three poles for each wheel. The poles are from ten to twelve inches in diameter at the small end and are hewn to a six inch face, giving an eighteen inch bearing surface for each wheel.
(See ill.u.s.tration on page 29.) The minimum sized pole that should be used for roads of this character is one eight inches in diameter at the small end. The road is constructed the same way as the single pole road and the poles are laid on cross ties twelve inches in diameter placed from eight to ten feet apart. Where the road is off the ground as when crossing over a small depression, these sleepers must not be over five feet apart. The guard rails at this operation are held in place by means of a wooden brace nailed from each end of the rail to a near-by stump.
The ends of the poles used for the track are adzed so that they match evenly. By breaking the joints and hewing them the road presents a level surface with no b.u.mps.
In planning the curves, it is necessary to make the tracks somewhat wider than on straight stretches in order to keep the trailer from running off. The track should be three feet wide on sharp curves and provided with a stout guard rail if there is any danger of the truck leaving the track. The curves are banked on the opposite side from that used on railroad curves. That is, the inner rail is raised about three inches. This is to throw the load to the outside away from the inner guard rail, making it easier to make the turn without the rear wheels binding. In this way a 35 degree curve may be negotiated with forty or fifty foot logs. As the curves have to be pa.s.sed at a much reduced speed, there is little danger of the logs rolling off due to the raised inner rail.
The grading for a road of this construction is usually light. The grades should, if possible, be kept below five per cent. A truck will operate better on a ten per cent grade in dry weather than on a five per cent one in wet weather. On a road of this type, grades up to ten per cent can be operated over unless there is snow. When the grades are above this and the weather is wet, traction still may be secured by sanding the road or by tacking an old half inch steel cable to the road in the form of a figure ”s”. If this is sanded in addition, the truck may safely be taken up a steeper grade than it would be safe to bring it down without sanding.
The pole road could be greatly improved by hewing the faces of the poles where they come together side by side so that an even fit is made. The details of this improved form of construction are shown in figure 1, page 30.
[Ill.u.s.tration: The most common type of motor truck logging road--a fore-and-aft pole road.]
[Ill.u.s.tration: Figure 1. Cross section of pole road. Scale--1 inch equals 2 feet.]
At the present time this is not done and there are one or more ruts in the surface of the road due to the rounding off of the poles where they are placed side by side. The front wheels of the truck are constantly dropping into these ruts, tending to spread the track apart and making it harder for the driver to steer. The tires also suffer from uneven wear. With this deep groove in the track, a certain amount of the traction of the rear wheels is also lost. Hence a much better road would be one with the inner faces of the poles hewn so that a tight fit is secured.
This road can be built of two large poles or three smaller ones to give a flat track two and a half feet wide for each wheel. Laid nearly flush with the ground the guard rail can be eliminated with this width of track, except on sharp curves and other locations where there would be danger if the truck left the track. On such a road the traction will also be increased, better time can be made, the truck will be easier to steer and hence safer to operate, and there will be less wear on the tires. Such a road can be very easily and cheaply built by bringing in a portable sawmill and slabbing the material on two sides to the desired face.
The life of a good pole road is from three to four years if kept in good repair. The maintenance cost is very light if the road is properly constructed in the first place, consisting chiefly in removing a pole here and there that shows signs of too much wear, and in bracing guard rails where they weaken. The use of two or three hewn poles laid lengthwise for each wheel without cross-ties does not pay as the poles soon get out of place even when trenched, and the loss of traction due to the irregularities and of time and money in the upkeep of such a road more than justifies putting in a good road in the first place.
The cost of a fore and aft pole road varies with the accessibility of the material and the cost of the labor. In the past they have been built for as low as $2000 a mile, but with the present prices costs will range from $5000 to $7000 a mile. One company within the year contracted the grading and construction of the road for $70 a hundred foot station, not including the cost of clearing and chunking out the right of way. The total cost was about $125 a station or $6600 a mile.