With a good road of this type and a bearing surface of thirty inches, the trouble and expense of a guard rail may be eliminated. When a light truck is used for a small body of timber such a wide and heavily constructed road is not practical. In this case, a four inch plank with a fifteen inch surface and an eight inch pole for a guard rail would be used. Here again the track must be made wider on the sharp curves, often as wide as three and a half feet. Usually, the inner rail is made wider than the outer one. On very sharp curves the track may have to be planked solid to keep the trailer from running off. By sawing out chips from one-half to one inch wide two-thirds of the way through the plank, and about six feet apart on the inner side, a long plank may be bent around quite a sharp curve. The ties, of course, should be placed so as to allow the cut sections of the plank to rest squarely on them. This does away with the short pieces and so strengthens the track. The company logging at Camano Island, Washington, operates over a road of this type, an illustration of which is shown on page 38. The difficulties encountered in the construction of this particular road were very considerable as a cut through very hard shale, in some places as much as seven feet, was necessary. The maintenance on this road is heavier than is usual. Two men are employed to work on it continually. The work consists of blocking up the loose ties and plank, making any necessary repairs and keeping sand and gravel on the steep grades. The cost of this work is good insurance as it keeps the road in the best of condition at all times and saves on other operating expenses. [Illustration: Detailed view of fore-and-aft plank road, showing method of wedging.] _Cost._ The first cost of a road of this type is high but it more than pays in the long run if a large body of timber is to be hauled over it. The timber used in its construction amounts to about 160 thousand feet per mile. Second grade material can be used at a cost of approximately $5,500 a mile for the plank. The total cost per mile varies from $6,000 to $8,000. The plank road at Camano Island cost $20,000 for two and three-quarter miles, which includes the cost of the plank, the grading and labor of putting the plank in place. This is at the rate of about $7,275 a mile, or approximately $138 a hundred foot station. The overhead charge for the road at this operation is $.75 a thousand feet of timber hauled over it. Plank roads of lighter construction have been built for $4,000 a mile. The length of life is about the same as that of a pole road, three to four years.