288 LOGGING 
track, for it is dangerous to run trains at high speed on a curved 
track which has a descending grade. In addition to their in- 
fluence on the hauling ability of a locomotive, steep pitches 
are a disadvantage on a road because the track tends to work 
towards the lower levels and not only is the expense of main- 
tenance greater than for a fairly level road but also the danger 
of wrecks is increased. 
(4) Where logging railroads must cross ridges or ascend or 
descend very steep grades in a short distance, ''switch backs" 
are preferable to doubling back with a curve since the latter 
method often necessitates a heavier construction expense. Switch 
backs and. inclines often are the only means at hand for securing 
timber from elevations above or below the main line. 
(5) Grades should not exceed 3 per cent and curves should 
not exceed 12 degrees on roads that are to be used for several 
years and over which a large amount of timber is to be hauled, 
although in a rough region these figures are often increased in 
practice. 
Location in a region without marked topographical relief, such 
as the flat pineries or the cypress swamps of the South, presents 
no special difficulties. The main object is to bring the railroad 
to the timber by the shortest and cheapest route. The con- 
struction cost is low on dry lands in these regions, because only 
limited quantities of material, chiefly earth, must be moved to 
make the roadbed. Where swamps are crossed piling is used 
and numerous bridges or trestles may be required, but even here 
the cost per mile is less than the average in a mountainous region. 
In the flat and gently rolling regions of the South the main 
lines often are located by the woods foreman, although in many 
cases, engineers could be employed to advantage. In a rolling 
or rough country, location presents difficult problems, because 
roads must be confined chiefly to natural drainage and often the 
only means of access to timber is over a route requiring heavy cuts 
and fills and expensive bridge and trestle construction. The loca- 
tion of logging railroads in a rough region should be done by a 
location engineer who is an expert logger. Good railroad engineers 
without logging experience are usually a failure at logging rail- 
road work because they are not able to subordinate some of their 
ideals regarding standard railroad construction to the demands 
of practical logging. Some companies have sufficient work to 
