204 BULLETIN 711^ U. S. DEPARTMENT OF AGRICULTURE. 



{d) The principal part of the maintenance of way is the labor of 

 section crews. Ordinarily five men under a section foreman should 

 keep 6 miles of main line logging railroad in good condition. 



With the exception of a small expenditure for tools and rail fas- 

 tenings, the rest of track maintenance is made up of tie replace- 

 ments. The life of ties is taken up in the discussion headed "Track 

 materials " in this section. 



EQUIPMENT. 



The equipment in the main consists of locomotives and cars or 

 trucks. 



(1) Locomotives. — There are two general types of locomotives 

 used, rod or straight connected, and geared. The type used in a 

 given case is determined largely by the grades and curvature of the 

 road. 



The rod engine is universally used on the common carrier rail- 

 road. In it the power is transmitted from the cylinders to the 

 drivers by means of a connecting rod. Rod locomotives have a 

 longer wheel base than geared locomotives, and so can not take as 

 sharp curves. They make better time, however, and cost less for 

 maintenance, proving the most satisfactory type on relatively long 

 hauls and where the road is smooth, well maintained, and of easy 

 grade. To secure good service with a rod engine, the maximum 

 grade empty should not exceed 3 per cent; the maximum grade 

 loaded, 1^ per cent. However, there are a number of rod engines 

 working on roads having grades of 5 per cent. The maximum 

 curves permissible are about 25 degrees. 



A special form of rod locomotive is used to a limited extent in the 

 region. Its essential features are two sets of sngines mounted under 

 the boiler, each connected to two independent groups of drivers. 

 This has the effect of materially shortening the wheel base, permit- 

 ting the use of heavy rod locomotives on roads having curves that 

 are too sharp for the regular type of rod locomotive of the same 

 weight. It is claimed that this engine can start greater loads than 

 the ordinary rod engine of the same weight. One weighing 121 tons 

 is operated on a road having 35-degree curves and 8 per cent grades. 

 There are several makes of rod locomotives on the market. 



Bryant, in " Logging," states that the first geared locomotive was 

 constructed about 1885 by E. E. Shay, a Michigan logger; and this 

 type of locomotive, with some modifications and improvements, is in 

 extensive use to-day. Two other forms of geared locomotives are 

 now in use in the region. 



Most of the locomotives used in logging in the region are of the 

 geared type. This is because sharp curves, heavy grades, and rela- 

 tively rough roadbed, which the geared locomotive is designed to 



