234 transactions of royal scottish arboricultural society. 



Preserving Sleepers from Decay, 



The Atchison, Topeka, and Santa F6 Railroad has recently 

 put into operation at Somerville, Texas, a large plant for treating 

 railway sleepers. The process used is that known as the 

 Rueping. The seasoned timber is first subjected to an air 

 pressure of 60 lbs. to 75 lbs. per square inch, after which creosote 

 is forced into the pores of the wood at a pressure of from 150 lbs. 

 to 250 lbs. per square inch, according to the nature of the wood, 

 until the fluid has penetrated all the cells. The pressure being 

 then withdrawn, the air contained under pressure in the cells 

 forces out all superfluous fluid. There is thus required only so 

 much of the impregnating fluid as is sufficient to coat the cells. 



The impregnation cylinders, of which five are now installed 

 with provision for a sixth, are 132 feet long by 74 inches in 

 diameter, and are adapted to withstand a working-pressure of 

 250 lbs. The end doors are hinged to heavy cast steel flanges, 

 and a part of their weight, which amounts to 4 tons, is 

 carried by a wheel running on a T-rail as the doors are 

 opened or closed. The doors are also secured to the flanges 

 by 36 hinged bolts which enter slots in the edges of the door, 

 and may be released and thrown out of the slots after a few 

 turns of the nuts. The pressure on the door when working at 

 the maximum is 537 tons. Rails run the entire interior length 

 of each cylinder, and between the rails are steam coils for 

 heating the oil to about 180° F. The cylinders rest upon 16 

 cast-iron saddles, to one of which they are secured. On 

 the other saddles are rollers to provide for movement under 

 expansion and contraction. Each cylinder will hold 16 cars 

 loaded with 37 sleepers each, making a total charge of 592 

 sleepers for each cylinder. The capacity of the plant is from 

 10,000 to 15,000 sleepers in twenty-four hours. 



There are now installed two pressure cylinders with provision 

 for a third, the intention being that one pressure cylinder shall 

 supply oil to two impregnating cylinders. These are 6 feet in 

 diameter and 106 feet long, each having a capacity of 22,500 

 gallons. They are adapted to a working-pressure of 100 lbs. 

 per square inch, and are fitted with steam coils, providing about 

 800 square feet of heating surface. 



Pressure for the impregnating cylinders is obtained by four 

 plunger pumps with pot valves, which are required to work at a 



