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 illustration 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, Washington, 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 bumpy. 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 space 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.