2688 Chapter 22 



POLES AND PILING 



In the South and Southeast, markets for poles and piling are dominated by 

 southern pine which is readily pressure-treated and obtainable in lengths and 

 diameters usually required; some oak piling is sold, however. Hickory and oak 

 roundwood has outstanding strength, stiffness, and ability to absorb impact 

 energy (table 22-26, see 8-inch roundwood), but these hardwoods are not as 

 readily treated as pine, and pine-site hardwood trees do not commonly yield long 

 straight stem sections. 



RIVER-BANK AND ROAD MATS 



Since before World War II, U.S. Army engineers have constructed wood 

 mattresses to control erosion of dikes and high banks of alluvial soil at bends in 

 the Mississippi River below Cairo, 111. Davis (1937) found that they annually 

 consumed in excess of 15,000,000 board feet of pine and mixed hardwoods — 

 mostly 1- by 4-inch boards. These wood mattresses are woven into great sections 

 from 40 to 100 feet wide and many times as long. When spiked and wired 

 together, they are sunk at critical points. The weaving of the mattress is done on 

 a barge which moves downstream as work progresses. The bank on which the 

 mattress is laid is given a gradual slope of not more than a foot downward for 

 every 3 feet horizontally. After the mattress is sunk into place, the bank is paved 

 with stone down to about the waterline covering the upper edge (apron) of the 

 mattress. Stone cast from the barge is used to sink the outer part. The entire 

 wood structure is anchored to the shore with cables. 



Logging mats have been, and continue to be, occasionally used in place of 

 gravel on temporary logging roads in purchased stumpage tracts, and at loading 

 decks, trailer set-out areas, chip- van concentration areas, and on localized soft 

 spots. These logging mats, made primarily from 4/4 oak lumber, are hand nailed 

 into 18- to 30-inch-wide, 16-foot-long assemblies. First two or three 16-foot- 

 long 1 by 6 or 1 by 8 runners are laid on the ground spaced to yield the 18- to 30- 

 inch width and then narrow slabs cut to 18- to 30-inch lengths are nailed on 4- 

 inch centers across the 16-foot boards. The assembly is then turned over, and the 

 nails clinched. The mats are then placed end to end in dual arrangement, with 

 crosspieces uppermost, to support the wheels of trucks. Because mats are used 

 before major rutting occurs, they lie relatively flat. Boyer,'^ who provided this 

 description, noted that after tracts are cut about 60 percent of the mats are 

 reusable; the major problem in using such mats is flat tires from nails remaining 

 in the bottom boards after crosspieces have broken. Boyer's analysis indicates 

 12 such reusable mats might be substituted for 60 tons of gravel at a saving of 

 about $270; gravel used on a road bed becomes a permanent part of the tract, 

 whereas the mats are removable. 



Oil well drillers operating in bottomlands of Louisiana and Mississippi use 

 significant volumes of 4/4 and 8/4 hardwood mats of similar construction. 



^^Boyer, R. L. 1977. Logging mats — an alternative to high-cost gravel. Paper presented at Spring 

 Meeting of the American Pulpwood Association, Appalachian Technical Division, Williamsburg, 

 Va., May 18-19. 2 p. 



