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--Relative advantages of different types of tires --Laws governing operation of motor vehicles--Legal limit of weight of load--Chain drives--Tops. TRAILERS 17 Draw-bar pull of motor trucks--Effect of grades on draw-bar pull--Advantage of trailer--Description of trailer--Brakes on trailer--Air brakes on trailers. LIFE AND DEPRECIATION 20 COST DATA 20 Operating expenses for 3½ and 5-ton trucks--Fixed charges-- Total expenses. ROAD CONSTRUCTION 24 Sub-grade--Cross-plank roads--Fore and aft pole roads--Cement roads--Guard rails--Cost of road construction. BRIDGES 36 TURNING DEVICES AND TURNOUTS 37 Construction of turn-tables--Turning of trucks. TELEPHONES 39 INCLINES 39 Snubbing methods--Practicability of inclines. YARDING 41 LOADING AND HAULING 41 Methods of loading trucks--Loading with boom--Rigging of boom--Unloading. TIME STUDIES 45 CONCLUSION 46 Future use of the motor truck--Motor trucks and forestry. BIBLIOGRAPHY 48 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