THE WEIGHING OF MARKET HAY. 25 



to a stop upon the scale and the weigher is then compelled to " catch " 

 the weight as the car passes slowly over it. Weight's obtained in 

 this manner are likely to be inaccurate, are not fair to anyone con- 

 cerned, and should not be used as official weights. 



The correct way is to weigh the car standing still and uncoupled 

 at both ends. As the scale track, when a car is on it, is lower than 

 the track adjoining at each end, if the slack is taken up taut, espe- 

 cially in a long string of cars, the weight indicated will be less than 

 the actual weight. Conversely, in a long string, with no slack taken 

 up, the weight indicated will be greater than the actual weight. 



Care must be taken also in weighing cars during a high wind, 

 as the weight of a car may vary several hundred pounds between the 

 highest and lowest pressure of the wind. 



Some railroads have installed automatic weighing devices at scales 

 where considerable weighing is done, which greatly facilitate the 

 weighing and guarantee correct weighing if properly operated. The 

 device or recorder is attached to the end of the weight beam and 

 eliminates the use of the poise weight. The movement of the beam, 

 which is regulated by balance weights in the mechanism, causes a 

 wheel upon which weight designations are set in type to revolve until 

 the number indicating the weight of the load is in position to print 

 the amount upon a ticket. 



Tripping levers are placed alongside the car rail at each end of the 

 scale which indicate the passing of the car onto and off the scale and 

 also operate the printing mechanism. Cars which are to be weighed 

 are pushed upon the scale or rolled onto it from a slight incline or 

 hump. A ticket is placed in proper position in the recorder mechan- 

 ism. As the car passes clear of the first tripping device onto the 

 scale, the beam comes to a balance automatically and the printing ar- 

 rangement is released and stamps the weight in 100 pounds upon the 

 ticket. As the car passes off the scale the second tripper is operated 

 and sets the weighing attachment for the next car. 



It is claimed that this weighing mechanism will weigh and record 

 the weights accurately so long as the car does not pass over the 

 scales at a speed greater than 5 miles an hour. It is necessary for 

 cars to be free from each other, however, and unless the first car has 

 passed the second tripping arrangement the following car can not be 

 weighed. 



THE TARE WEIGHT. 



When cars are weighed by railroad companies the tare weights 

 stenciled on the cars are usually used, as there is no opportunity to 

 weigh the empty car. Railroad cars are weighed when put into serv- 

 ice and usually after any extensive repairs have been made. New 

 cars are also generally reweighed after they have been in service 



