MOTOR TRUCK LOGGING METHODS
BY
Frederick Malcolm Knapp
Student in the College of Forestry,
University of Washington.
SEATTLE, WASHINGTON
PUBLISHED QUARTERLY BY THE UNIVERSITY
APRIL, 1921
Entered as second class matter, at Seattle, under the Act of July 16, 1894.
CONTENTS
Page INTRODUCTION 5 HISTORY OF TRUCK LOGGING 5 First use of motor truck in logging—Development of logging trailer—Possibilities in the use of motor trucks. TRANSPORTATION OF LOGS—RAILROADS VERSUS MOTOR TRUCKS 7 Comparative advantages and uses of motor trucks and railroads—Relative cost of road construction—Advantage of flexibility of motor trucks. COSTS 8 Operating costs of a typical 5-ton truck—Actual cash outlay—Total expense—Variable charges—Recapitulation of work performed. ROLLING STOCK EQUIPMENT 10 Rigid versus flexible truck bodies—Chain drive versus worm drive—Weight of trucks—Speed—Depreciation. INSURANCE 14 Fire and theft insurance—Collision insurance—Liability insurance—Property damage insurance. TRUCK EQUIPMENT 14 Bunks—Tires—
INTRODUCTION
In this paper an attempt has been made to bring together some useful facts concerning the application of the motor truck to the logging industry. The term “motor truck” as here used is applied to the ordinary truck type of motor vehicle with trailer adapted to carrying logs, and does not include the “tractor” and the “caterpillar tractor.” These latter types present special problems of their own. In the following pages the discussion of motor truck logging is premised upon conditions as they exist in the forests of the Pacific Northwest.
HISTORY OF TRUCK LOGGING
Motor trucks in the logging industry are a comparatively recent development. As nearly as can be determined, the first use of a truck in a logging operation was made in this region by Palms and Shields near Covington, Washington, in the spring of 1913. Since that time various types of road construction suitable for heavy trucks have been devised and the use of the motor truck for logging has steadily increased until at the present time there are about six hundred trucks operating in the woods in the Northwest.
The first real progress in the use of the motor truck for logging purposes came with the development of the trailer. Although the motor truck has been brought to its present high state of perfection in eastern factories the problem of adapting it to the hauling of massive logs was solved in Seattle, Washington, with the perfecting of a trailer which could carry unprecedented loads and stand up under the speed attained by a motor truck. In the early attempts to design a trailer, it was found that too great tractive effort on the part of the truck was required if the trailer was patterned after older types with simply increased dimensions in all of its parts. Through successive improvements the modern form of heavy duty trailer was finally evolved. It has solved a serious problem by permitting the hauling of heavier weights with the aid of the trailer than is possible with the use of the truck alone. With the help of the trailer and an adjustable reach, the motor truck has successfully entered the logging field.
In the Pacific Northwest tracts of timber of sufficient area well situated for economical logging by old established methods are no longer plentiful. Almost every logging chance which exists today presents its own peculiar conditions and individual problems. An operator must therefore analyze the situation thoroughly before arriving at a decision as to the most economical logging methods that will apply in any particular case. Even in different sections of the same operation it is often necessary to use different methods. Since proper cost accounting systems are not usually kept by logging companies, particularly the smaller concerns, these companies often do not know that they are losing money upon one part of an operation because the success of the whole absorbs this loss.
Pioneer logging with a motor truck in 1913.
The use of a motor truck has proved to be practicable in many instances, and bids fair to become of increasing importance. It will therefore be advantageous for every operator to inquire into its possible applications. It should be emphasized, however, that the motor truck is not economically adapted to all conditions. There have been many failures. Each projected application of the motor truck in the logging field must be thoroughly analyzed and if a doubt as to its successful performance exists, expert advice should be sought.
TRANSPORTATION OF LOGS—RAILROADS VERSUS MOTOR TRUCKS
The principal methods of transporting logs are by rail, by motor truck and by animal power. The last of these methods is, for obvious reasons, impracticable in the Northwest, and so needs no further comment. While it is impossible to give specific details in a general discussion of this kind to show where the motor truck may be more economically suited to the conditions at hand than the railroad, a comparison of the fundamental principles involved should enable any operator familiar with logging to determine whether or not to use the truck for his particular chance.
In general the choice between railroad and motor truck logging depends, fundamentally, upon two things: (1) comparative cost, and (2) adaptability. Sufficient motive power and rolling stock can be obtained much more cheaply for motor truck logging than for a railroad. There are, of course, many situations where the locomotive and car costs, as well as those of constructing a logging railroad, are obviously prohibitive, and the question revolves entirely upon the adaptability of the motor truck to existing conditions. There is no question at all that the logging railroad is not adapted to small, isolated and scattering tracts, and to certain portions of larger operations. There are almost innumerable tracts situated close to public highways, or where temporary roads can be built,
Wherever the item of road construction is important, it may be stated in general that the time required and the cost of building roads for motor trucks are very much less than for a logging railroad. This is due to the lesser importance of grades, curves, ballasting, bridges and other construction work, all of which is much cheaper and takes less time. In case a pole road is built the material found adjacent to the right of way can be utilized for what it costs to fell it.
From the standpoint of adaptability the motor truck is very flexible. It can operate on grades and curves that are impossible with the railroad. The whole logging equipment, including the donkey engine, can be loaded on the truck and trailer and easily moved from one setting to another. By replacing the log bunk with a platform the truck can take out all the smaller marketable material, such as shingle bolts, poles and cordwood. The modern truck can also be provided with the necessary equipment for use in snaking out the logs in stands of small timber and when used with a winch and an “A” shaped boom, will load itself. If the truck becomes mired in a mud hole, the winch may be used to pull it out. Finally, the item of fire risk is practically negligible.
COSTS
In order to arrive at definite figures as a basis for a comparison between railroad and motor truck transportation costs, the following case is cited as an example representing average good conditions:[1] A 5-ton truck with trailer was used, operating on a seven and one-half mile haul over ordinary unpaved roads. An average of four trips a day were made and the actual running expense for hauling was $.901⁄2 per thousand feet. Adding to this the overhead expenses of interest, depreciation, etc., the total cost of hauling was $1.44 per thousand feet. The statement of this cost is as follows:
[1] West Coast Lumberman. Nov. 1, 1916, page 266. Labor, gas and oil have since advanced in cost.
Actual Cash Outlay in Hauling 128,420 Board Feet of Logs
Gasoline, 284 gallons @ $.19 $53.96 Oil, 3 gallons @ $.60 1.80 Oil, 201⁄2 gallons @ $.45 9.23 Incidentals—One electric light globe .35 Hardware 4.03 Blacksmith 3.00 Driver, 11 days @ $4.00 44.00 Total $116.37128,420 feet @ $116.37, or $.901⁄2 per thousand feet.
Total Expense of Hauling 128,420 Board Feet of Logs
Investment: Chassis $4,900.00 Trailer 700.00 Total Investment $5,600.00Variable Charges
Gasoline, 284 gallons @ $.19 $53.96 Oil, 3 gallons @ $.60 1.80 Oil, 201⁄2 gallons @ $.45 9.23 Tires, $.071⁄2 per mile on 615 miles 46.12 Incidentals 7.43 Total variable charges $118.54Depreciation (based on 15% per annum on $5,600, less $560, the cost of the tires, or $5,040.00) $1.34 9 Interest on amortized value at 7% .63 Storage, $5.00 a month .20 Driver @ $4.00 a day 4.00 Total fixed charges $6.17 9
Total variable charges $118.54 Total fixed charges at $6.179 a day for 11 days 67.97 Total cost $186.51
128,420 board feet of logs @ $186.51, or $1.44 per 1000 feet.
Following is a recapitulation of the work performed by a 5-ton logging truck, Jan. 20 to Jan. 31, 1916, inclusive. The logs were hauled from O’Neill’s Camp on the Bothell-Everett road 71⁄2 miles and dumped into Lake Washington at Bothell.
Date Trips Mileage No. Ft. Hauled Gas Used Oil Used 1/20/16 4 60 10,768 30 2.25 1/21/16 4 60 11,888 24 2.25[2] Freight truck in the ditch. Four hours lost getting the road cleared.
[3] Two hours lost at the landing due to a spring slipping out of place, which made it necessary to unload and load again.
Many loggers who have used both the steam railroad and the motor truck claim that the latter is preferable in some cases and often is the only method by means of which logs can be gotten to the mill at a reasonable cost. Where the stand is scattered and of poor quality, the building of a railroad is not practical. In such a case the motor truck may offer the only solution.
The motor truck makes the best showing when hauling from one “side.” With a two or three side operation the railroad is by far the more practical. It must be remembered, however, that the railroad and the motor truck are not competitors in the logging industry—they are allies.
ROLLING STOCK EQUIPMENT
In general two plans are followed in building a motor truck. The first is to build a rigid truck so that it will resist all shocks and distortions that come from rough and uneven roads. The second plan is to build a flexible body so that the chassis will “give” rather than resist when subjected to hard strains. Although the rigidly-built truck may be entirely satisfactory for most forms of trucking, it is practically impossible to build one on the rigid principle that will stand up under the heavy strains to which a logging truck is subjected unless it is to be operated over good paved roads. When only ordinary unpaved public roads are available, flexibility is one of the most important characteristics to look for when selecting a truck. Where the operator is hauling over his own pole or plank road this consideration does not play so important a part, as the road bed then is more likely to be free from holes and irregularities.
All makes of trucks are more or less alike in general construction, differing only in minor details, so that the personal whims of the buyer will largely determine the kind he will select. It is advantageous to have as long a distance as possible between the driver’s seat and the bunk over the rear axle, in order to allow more of the load to be carried by the truck, and less by the trailer, giving better traction to the drive wheels, but necessitating extra strong rear springs and axles.
The type of power transmission best suited to the use of the logging truck is a question that has received a great deal of attention. There are three general methods of transmitting the power: (1) by chain; (2) by worm drive, and (3) by internal gear drive. Each has its advantages. It is claimed by many that the chain drive saves many hours of “shut-down time” due to the fact that if anything breaks in the transmission, it will be a link in the chain as this is the weakest point. It is then only a matter of a few minutes to insert another link. With the worm driven vehicle, a break in the transmission requires an expensive shut-down before the matter can be repaired. The worm drive, on the other hand, very seldom breaks if proper care is used.
The chain drive also allows the replacement of the sprocket with one of a larger or smaller diameter thereby giving a higher or lower gear ratio, which cannot be done with the worm gear. This seems to be of some advantage to an operator when changing his setting from one with a short haul and steep grades where a low gear ratio is required, to one where the haul is long and fairly level, and where speed in transit is an advantage.
On the other hand, in starting on slippery grades or wherever the traction is poor, the worm drive will give better traction than a chain drive because there is difficulty in taking up the slack that is always present in the chain before letting in the clutch fully. The slightest jerk given to the wheels when the slack is taken up is likely to cause them to spin, thereby losing all the tractive power of the drive wheels. In the worm gear there is no slack to take up and the power can be applied more gradually, thus reducing the chances of spinning the wheels and losing the traction.
The question of the weight of the truck used for logging purposes is not as important now as it will be in the future. Laws are being passed in nearly every state limiting the maximum weight to be carried on each wheel by trucks using state or county roads so that the total weight of the truck without load will be important. When operating over state or county roads the load is limited to from 2400 to
Whenever the legal weight limit does not enter into the problem, as in operating over a pole or plank road for the entire distance, it is, of course, advantageous to carry the largest loads possible. In such cases a 5-ton truck with an 81⁄2-ton trailer is the most profitable investment. This allows a much larger load to be carried in proportion to the overhead charges. The disadvantage of the 5-ton truck is that it is very heavy and unless the roads are good, it will easily sink into the ground and cause trouble. A common fault of the 5-ton truck today is the overweight of the front end, which is too heavy for the width of tire on the front wheels. This can be very easily overcome by the use of wider tires.
LIFE AND DEPRECIATION
The life of a truck is directly proportional to the care that it receives, hence, a good driver is a most important consideration. If the right man can be secured his wages should be a secondary consideration.
The charge to be made for the depreciation of a truck is an uncertain question. Some loggers figure on the basis of four and a half years, others on as much as seven years. The depreciation charge on a truck used in the logging industry should depend largely upon the type of road over which it is operated. Loggers in general over-rate the life of their equipment because they do not fully realize the severity of the work. Over a fore and aft plank road or a cement road, where the jar and vibration are reduced to a minimum, the wear and tear on the equipment is very much less than where the truck is operated over a cross-plank road or an unpaved public road. The matter of depreciation, then, will depend largely upon the type of road over which the truck is to operate. In general a four-year depreciation charge less 25% sale value at the end of that time should be used as a basis for figuring costs unless the hauling conditions are very favorable. Only under very rare circumstances should more than four years be allowed. It should be remembered that the depreciation on a truck is very heavy during the first year, and the sale value at the end of a year is only half the original price. Many truck operators now hauling over good roads who are depreciating on the basis of five years say that a four-year depreciation would be more nearly correct. Another factor in favor of a four-year depreciation charge is that methods of logging are changing constantly and that trucks in that time may be improved upon to such an extent that the use of the old equipment would be unprofitable and inefficient.