284 LOGGING 



to them. The track is then ballasted with bark, edgings, saw- 

 dust and sawmill refuse of all sorts which is brought from the 

 mill in ''dunnage" cars. The dunnage is dumped on either side 

 of the rails, then thoroughly tamped under the ties and, when the 

 track is leveled up, it is ready for operation. Light-weight 

 locomotives, from 18 to 30 tons, are used because this type of 

 roadbed will not stand heavy trafitic. 



The labor cost of constructing dunnage roads including the 

 laying and taking up of steel is from $1300 to $1500 per mile. 



Cribwork. — A crib foundation may be used when logging 

 railroads cross low places that are too soft for a fill, and where 

 the lumber company is not prepared to put in piling. Logs 18 or 

 24 inches in diameter and 16 or 18 feet long are placed across 

 the right-of-way at intervals of 8 feet. On top of these, and 

 parallel to the roadbed, round stringers from 18 to 24 inches in 

 diameter are placed 56I inches, center to center. These are 

 notched into the cross-skids and drift-bolted to them. The 

 crossties are then laid on top of these stringers. The cross- 

 skids are given a greater bearing surface by placing "shims" or 

 poles from 4 to 6 inches in diameter and 8 or 10 feet long at 

 right angles under them. 



Labor on work of this character costs from $4 to $6 per thou- 

 sand feet of timber used. 



Corduroy for Logging Roads. — An excellent practice followed 

 by some loggers in the South is to corduroy unballasted spur 

 tracks on wet ground with 16- or 20-foot poles from 4 to 12 inches 

 in diameter (Fig. 80). A pole is placed in the space between 

 the ties and projects out far enough on either side to rest on 

 solid ground or roots. The poles provide a level support to 

 the track. Even though it does sink temporarily under the 

 weight of the train, it will go down on a level, so that there is 

 no danger of derailment, while shims placed under the ties par- 

 allel with the roadbed often allow the track to settle on one side. 



When spurs cross swampy ground, some loggers dispense with 

 ties, and cover the roadbed with poles 10 or 12 feet long to 

 which the rails are spiked. A road of this character will support 

 light traffic even on a very wet bottom. 



