WHAT TO DO WHEN THE TENDER IS FOUND EMPTY BETWEEN STATIONS.
The most natural cause for pumps or injectors ceasing to work, is absence of water from the tender. This condition comes round on the road occasionally, where engineers neglect to fill up at water-stations, or where there are long runs between points of water-supply. When an engineer finds himself short of water, and the means of replenishing his tank too distant to reach, even with the empty engine, he should bank or smother the fire, and retain sufficient water in the boiler to raise steam on when he has been assisted to the nearest water-tank. This will save tedious delay, especially where an engine has no pumps. Occasionally, from miscalculations or through accidents, the fire has to be quenched, and insufficient water is left in the boiler to start a fire on safely. In this event, buckets can be resorted to, and the boiler filled at the safety-valves, should there be no assistance, or means of pumping up. Every possible means should be exhausted to get the engine in steam, before a runner requests to have his engine towed in cold.
A TRYING POSITION.
I once knew a case where an engineer inadvertently passed a water-tank without filling his tender. He had a heavy train, and was pushing along with a heavy fire, on a severe, frosty night, when every creek and slough by the wayside was lost in heavy ice. Presently his pump stopped working, and he spent some time trying to start it before he discovered that the tender was empty. By the time this fact became known, his boiler-water was low, and a heavy fire kept the steam screaming at the safety-valves. He had no dump-grate, and the fire was too heavy to draw. It seemed a clear case of destroying the fire-box and flues. But he was a man of many resources. First, he tried to get water through the gauge-cock—he had only one gauge—to quench the fire, but found the plan would not work. Then he filled up the fire-box nearly to the crown-sheet with the smallest coal on the tender, and partly smothered the fire. He then partly opened the smoke-box door, and started for the water-station. After getting the engine going, he hooked the reverse-lever in the center, and kept the throttle wide open, to make the most of the steam-supply. He saved his engine.
WATCHING THE STRAINERS.
When the top of a tank is in bad order, and permits cinders and small pieces of coal to fall through rivet-holes, or through seams, the engineer may look out for grief with his pumps or injectors. On the first signs of the water failing, he should examine the strainers; and he will probably find that these copper perforations, which stand like wardens guarding the safety of the pumps and injectors, have accumulated a mass of cinders that obstructs the flow of the water.
CARE OF PUMPS.
Mechanical prognostications seem to indicate that pumps, as locomotive attachments, have outgrown their usefulness, and that their days are numbered. They have done good service while no better method of feeding locomotive boilers was known; but, since the advent of injectors, pumps have begun to disappear. They still hold their own, however, on a great many roads; and a description of their management will be of general interest.
HOW THE CONDITION OF PUMPS CAN BE TESTED.
If an engineer is in the habit of pumping regularly, and of watching his engine closely, he can tell immediately from the steam when the pump stops working. Then he will open the pet-cock; and its action will indicate, to some extent, where the trouble lies. If the pet-cock throws a feeble stream of water, the trouble probably is in the lower valve. If that sticks up, or part of the bottom cage breaks, the plunger will push the water back into the feed-pipe on the return stroke, consequently there will be no pressure to throw a strong stream through the pet-cock. When the upper or pressure-valve is damaged, or is stuck up, the pet-cock will throw a full stream during the inward stroke of the plunger; but, on the outward stroke, the plunger will draw the water out of the branch-pipe, and air will be sucked in at the open pet-cock. When the check-valve is damaged, or stuck up, steam and water will blow back through the branch-pipe when the pet-cock is left open. If the steam thus escaping from the check-valves heats the pump and valves to a high temperature, it will be prevented from working, from several causes. The heat generates a low form of steam, which fills up the space behind the plunger; therefore, no vacuum is formed to draw the water. Not infrequently the pump-valves expand so much from the heat, that they stick fast away from their seats. If the pump has stopped through the presence of impurities on either of the valves or cages, the engineer knows that he may remove the obstruction by steam-pressure; so, after letting the feed-pipe fill with water, he opens the heater-cock, and closes the foot-cock, letting the steam and water blow through the pump. If he considers the obstruction to be in the strainer, and has not time to stop and take it down, he blows steam from the heater through to the tender, which gives temporary relief. If any of the pump-valves are stuck up, and can not be got back to their seats by blowing water and steam through them, the engineer will take a soft hammer, and tap the seats lightly, with good prospects of remedying the defect. In case no improvement can be effected in that way, and there is no other feeding-medium to rely upon, the engineer can take down the top or bottom chamber in a few minutes to remove any impurities that may be keeping the pump from working. He will then be likely to find a piece of packing that has passed through the pump, bushing, or some other foreign substance, jammed between the cage and the valve, keeping the latter immovable. Or the trouble may be a broken valve or cage, which will render the pump useless till repaired.