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, 1J 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 engines 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 
