HARDWOOD RECORD 



27 



multiplied by 1,440, and divided by 33,000 to 

 get it into horsepower, will be nineteen brake- 

 horsepower, required around curves and bad 

 sections of track. You still have a reserve, 

 due to the adhesion of the locomotive, of 

 about ten tons for heavy curves and grades, 

 but the motors will take care of this, because, 

 being series-wound, they can slow down and 

 deliver powerful torque when making such a 

 grade. A fair average service about the yard 

 will fall a little below 19 H. P., and so" two 

 TVi H. P. motors, which are the nearest 

 smaller size below the 10 H. P., will do very 

 well. It is very essential to keep the motors 

 as small as possible, as larger ones simply 

 waste the precious current of the storage bat- 

 tery in the controller resistance. 



The size of the battery will be the next 

 thing. You want it to work ten hours, and 

 at least half of that time it will be standing 

 still, or running light, hauling empties. The 

 average working current will be about 75 

 amperes for the time the locomotive is work- 

 ing, which will give about 350 ampere-hours 

 as the size of the battery, and this is as large 

 a battery as can be put on a 6-ton 

 locomotive without giving it considerable over- 

 weight. The reason the average falls so far 

 below the maximum amperage is because, in 

 the nature of yard service, heavy trainloads 

 of eighteen tons are never hauled more than 

 for a short distance at full speed, and, for 

 the greater part of the time, the work is 

 lighter, or at slower speed, or the locomotive 

 is negotiating a switch or a turnout, or 

 coupling. So the time goes by without using 

 the full amperage, which averages up at about 

 half for even the working time, which itself 

 is only about half of the ten-hour day. Our 

 locomotives come in pretty well run down, 

 and during the day transfer about 110 cars 

 loaded and the same amount empty. This is 

 about two five car trains hauled and returned 

 Jvery hour. 



A sample order for a six-ton locomotive 

 would be: "One electric storage-battery loco- 



SIX TON STORAGE BATTERY LOCOMOTIVE. 



motive, weight six tons ; maximum draw-bar 

 pull 2,250 pounds; equipped with 110-volt, 

 350 amp. -hour storage battery; two 7^/-; H. P. 

 series motors arranged to be used separately 

 or together; maximum height from top of 

 rail to top of cab, 5' 6" ; maximum width, 

 o' 3"; gauge of track, 36"; locomotive to be 

 complete with cab, inside wheels, brakes, cir- 

 cuit-breakers, tools, headlights and charging 

 board, and guaranteed to perform all services 

 as set forth in our attached specifications of 

 even date. ' ' 



The locomotive is usually shipped with the 

 batteries all set up and charged. If. for 

 transfer reasons, it is shipped with the ele- 

 ments packed, it is necessary to wash all of 

 them clean, and assemble the groups of plates, 

 the negatives being always gray, and the 

 positives brown. There is always one more 

 negative than pcsitive in a group. The elec- 

 trolyte is pure sulphuric acid of 1.S4 specific 

 gravity, mixed with distilled water to the 

 specific gravity of 1.200. The cells are filled 

 with it, and connected up and given an initial 

 charge of 72 hours, during which time the 

 gravity will slowly rise to 1.225. It is then 

 full charged, and the battery should be gas- 

 ing freely, and the voltage be up to 2.7 volts 

 per cell. It is now- ready to go out on the 

 job, and should discharge to the motors at 

 two volts per cell, plus a trifle, or 102 volts 

 for a 48-cell battery. At the end of the day 

 it will be down to about 90 volts, and should 

 never be allowed to get below 88, as stated 

 at the beginniug of this article. It is at once 

 put on charge at a charging rate of about 

 35 amperes, and it will be found that the 

 charging voltage will gradually have to be 

 raised from 103 volts up to 123, to keep the 

 current at 35 amperes during the first six 

 hours. At the end of that time it will sud- 

 denly jump to 135. and will take two hours 

 more to get up to the maximum of 137 volts, 

 when it is fully charged, and the gravity 

 should be up to 1.225 again. 



Every fifteen days the locomotive should be 



laid off for about four hour's time, and the 

 gravity and level of the electrolyte adjusted. 

 It will be found that the evaporation of the 

 water in the electrolyte will run the level 

 down from an inch above the plates to two 

 inches below their tops. Meanwhile the grav- 

 ity will have become high, as there is no 

 evaporation in the sulphuric acid. As the 

 acid is all down in the crevices between the 

 plates it must be siphoned out and brought 

 down to 1.225 outside before replacing in the 

 cells. Simply pouring in more water will not 

 answer. This cannot be done at night, for 

 the battery should be fully charged when the 

 gravity is adjusted. If it is still low in the 

 cells, after bringing down all that was 

 siphoned out to 1.225 by the addition of dis- 

 tilled water, do not add sulphuric acid, except 

 as a last resort. Fill up with distilled water 

 to an inch above the plates and give the bat- 

 tery an extra charge of three hours for sev- 

 eral nights running. If the gravity is still 

 below 1.225 you can then add enough sul- 

 phuric acid to bring it up. 



At the end of about six months' steady 

 service the locomotive will suddenly begin to 

 fall off badly in her work, and will come in 

 at about two o'clock, entirely run down, and 

 no amount of charging will remedy matters. 

 The trouble is that the mud-cellars in the bot- 

 toms of the glass cells have gradually filled 

 up with fine particles of lead-oxide, jarred 

 off the plates in service, and act as bridging 

 across the bottoms of the battery plates, thus- 

 connecting the negative and positive plates 

 below and draining out the current as fast as 

 it is charged in. In the earlier types of 

 storage batteries, where the plates were lead 

 grids with pockets filled with pastes of lead 

 oxides, this trouble was chronic, and prevented 

 any decent service at all in such rough work 

 as yard stock handling. But of late years 

 this type of plate has been replaced with 

 those in which a great surface of lead is 

 formed on the plate mechanically, either by 

 burring up the surface like the teeth of a 



