66. Underhung Springs and a Broken Tire."How should a standard eight-wheel American engine with underhung springs be handled in case of a broken tire? Spring saddle extends into the bottom of the driving box and is held in position by a pin?"-M. R.

Answer. This is a poor design of a driving box for a case of this kind, as the cellar is raised in the center to clear the steel pin that supports the spring saddle, this pin extending through the box is held in place by the face of the shoe and wedge. When the tire breaks, if it still remains on the wheel, it is necessary to keep it from the rail, and if it is broken so that it comes off the wheel, the wheel center must be raised to keep it from being damaged. We will take for example the forward tire broken. We will insert a block between the top of the back box and under the top rail of the frame, take out the cellar and see if we have space enough between the spring saddle and the journal to put in a block that will hold the broken tire from the rail. If not, it will be necessary to remove the pedestal or thimble bolt. Then run the back driver up on a wedge to raise the lower end of the pedestal jaws or legs of the frame above the pin. Take out the pin, remove the spring and saddle, and cut a block from the end of a timber or tie that will fill the space between the pedestal bolt and the journal when the wheel will clear the rail. Have it thick enough to allow for wear and settling. Chain the end of the equalizer to the frame and run the back wheel off the wedge. Then put the pedestal bolt back in place and tighten the nuts. Now put the wedge under the wheel with the broken tire and run the wheel up on it until you can insert the block between the pedestal bolt and the journal. Run the wheel off the wedge and you are ready to proceed. If the back spring is heavy enough to carry the load the blocks may be removed from the top of the back box and the back spring util

ized.

67. Engine Slipping with Heavy Train.-"If an eight-wheel engine was down on her back boxes would it have a tendency

Answer. An eight-wheel engine usually has about one-third of its weight supported by the engine truck and the other two-thirds supported on the drivers through the medium of equalizers and springs. The truck supporting the weight at the front end is one point and the fulcrums for the equalizers on each side of the engine form the other two points, thus forming a tripod to distribute the weight equally on uneven track. The two back points of the support place the weight on the fulcrums of the equalizers and it is transmitted to the springs, saddles, and hangers for the purpose of lessening the shock and equalizing the load on rough track. It is evident that each end of the equalizer must support one-half of the load or weight at the fulcrum and when one end of the equalizer moves down the other end will move up an equal distance and the weight on the support is the same as if the equalizer was in a horizontal position. Therefore, an engine slightly low behind or down on her back boxes would not lose her adhesion or be more liable to slip providing the points of support were the same and the equalizer free to move on the fulcrum. If the load intended to be carried on the drivers was transferred to the back boxes on account of their being blocked between the top of the box and the frame, the equalizing feature would be destroyed and the forward wheels would support little of the weight, if any. More weight would be carried by the truck and the result would be less weight on the drivers, which would reduce the adhesion and cause the engine to slip.

68. The Sight-Feed Lubricator.-"Does the oil fed through a sight-feed lubricator go from the lubricator to the valve by gravity, or is it forced down by a current of steam?"—C. B. R.

Answer.-Oil that is fed through a sight-feed glass of a lubricator rises to the top of the water in the glass by reason of the oil being the lighter, and the pressure of the weight of the water in the condensing chamber whose level is higher than the level of the water in the chamber above the sight-feed glass. The steam that flows through the equalizing tube forces water from condensation through the hole in the choke plug, keeping the water at a level with the opening. As the oil rises to the top of the water, the water and oil above this level are forced through the choker into

the oil pipe leading to the steam chest. When the pressure at the lubricator end of the oil pipe is the greater the oil is carried to the steam chest by the current of steam pressure. Oil being heavier than steam it would flow to the chest by gravity without the pressure of steam, but the movement would be slow. When the pressure at the steam chest end of the oil pipe exceeds the pressure of the lubricator end the oil pipe is sometimes filled with water, forming what is termed a pocket for the oil and preventing the flow of the oil to the chest until the pressure is reduced at that end of the pipe. Oil does not flow through the pipe as it appears in the glass. When the drop of oil rises opposite the hole in the choke plug the steam and water atomizes it and it is mixed in proportion to the amount of oil and water that pass through the choker. The valves and cylinders get oil and water. A sample of this can be easily obtained by disconnecting the oil pipe, starting the lubricator and placing a bucket under the end of the pipe. Various kinds of circulating valves and devices are used to insure a positive circulation through the oil pipes from the lubricator to the chest and maintain lubrication under the varying conditions.

69. Bridging Exhaust Nozzles.-"What difference does it make whether you put a bridge in an exhaust nozzle crosswise with the flues or parallel with them? A bridge is used here to spread the exhaust steam to fill the stack so the engine will burn her fire.”—A. H. W.

Answer. A bridge placed in a single nozzle has the effect of reducing the area

and increasing the back pressure in the cylinders. Spreading the steam to fill the

stack in this manner would have a tendency to further increase the back pressure, as it has been found that reducing the choke or small diameter of the stack

caused back pressure the same as reducing the nozzle. If the stack is out of line to one side or the other, placing the bridge parallel with the flues would cause the steam to fill the stack and produce a greater vacuum than if the stack was not filled by the exhaust. Should the stack be out of line, either forward or back of the nozzle, then it would be more beneficial to place the bridge crosswise of the flues, but it would be better to have the nozzle and stack put in line so that the expansion of the exhaust steam would fill it evenly. Bridging a nozzle is usually creating one defect to remedy the other.

70. What is the Defect?-"Please explain what defect, if any, and about what percentage of power is lost by the following: Long piston, cylinder is 18x24, 135 pounds of steam, and 55-inch driving wheel. Piston just clears the front end 1-64 of an inch, clearance on other engines of_the same make is 5% of an inch divided. This engine does not give satisfaction and the trouble can not be located anywhere except a long piston. If this affects the lead or pulling power, please advise."-Sap.

Answer. If this engine is still in service the clearance should be attended to at once, as it is not sufficient to allow for the keying of the main rod to take up the wear on the brasses, and there is danger of knocking out the front cylinder head. We will presume that this engine originally had 5-16 of an inch clearance at each end of the cylinder and the clearance on the front end was reduced on account increasing the length of the main rod by driving the keys. That being the case, we have 1-64 of an inch clearance on the front end and 39-64 of an inch on the back end. Neglecting the space between the circumference of the cylinder and the valve face, we would have a volume of clearance in the front end of about 4 cubic inches and a clearance volume in the back end of about 130 cubic inches. The position of the eccentric in relation to the pin is not changed, therefore, the lead of the valve would be the same, and if cutting off the steam at 5 inches of the stroke, or when the piston had moved 5 inches from the end of its travel, we would have a volume of steam in the front end of the cylinder equal to 1,276.5 cubic inches to force the piston back by its expansive force. In the back end of the cylinder we would have a volume of steam equal to 1,402.5 cubic inches to push the piston ahead, which would give a higher

mean effective pressure in the back end than in the front end of the cylinder. This increased volume of steam confined in the cylinder when the valve closed the admission port may cause the exhaust from the back ends of the cylinders to sound heavy. Would have the clearance divided for each end of the cylinder and take up the dome cover and see if the throttle valve opened enough to admit steam to the dry pipe in sufficient quantity to develop the required power in the cylinders. The throttle valve should lift 1/4 of an inch for each inch of its diameter to get the full opening. Does it?

71. Engine Doesn't Steam.-"Will you kindly give me your advice and the benefit of your experience on the following? The engine came here new last August with a

brick arch and up to some time ago did first rate. She has not been doing so well lately and have reported work as follows: 'New brick arch, bore out flues, clean out nozzle, etc.' She had been steaming pret ty well before this work was done, but tore the fire all to pieces, especially after being cleaned, knocking it through to the pan. They had no new brick to put in,

so took the remains of the one out entirely. They found the nozzle coated about 4 of an inch and cleaned that out. Now she does not steam nearly so well and burns all the coal you can pile on. Should the diaphragm be altered, and if so, higher or lower?"-C. G. B.

Answer.-An engine out of the shop six months should be in good condition if running in a locality where there is good water used, providing that the flues and firebox do not leak and the boiler is free from mud and scale. You have the same amount of heating surface, and with the valves and cylinder packing tight the engine ought to do good work. Although the brick arch is considered as an aid to combustion, the engine can be made to steam well without one, but it is usually necessary to lower the diaphragm about 3 inches when the arch is removed, pro viding that the front end was properly ad justed to steam with one. Lower the diaphragm to increase the draft in the forward end of the firebox and through the lower flues and raise it to increase the draft in the back of the firebox and through the upper flues. Change it until you get the fire to burn evenly on the grates. Would suggest that the exhaust pipe be examined and ascertain if it is not choked up below the tip, thereby reducing the area of the exhaust pipe which, with the uneven draft you may have, tears holes in the fire. See that the stack is in line with the nozzle, that the gasket between the exhaust pipe and cylinder saddle is not cracked or blown out, and that the exhaust from the air pump is directed up the stack and not against the pipe or smoke arch, thus destroying the vacuum in the front end. If the fire burns a dull red have the steam pipes examined for leaks. Go right after her and you will make steam. There is money

in it.

72. Working Full Stroke and Cut Back.-"All other things being equal, with sufficient boiler capacity to furnish the required amount of steam, could a locomotive, such as is run on the fast trains of today, make as fast time by working steam the full stroke of the piston as it will if cut back? If not, please explain why."-E. C. B.

Answer. With sufficient steam sup

plied to work a locomotive at full stroke, it is the general opinion that the engine would not run as fast as if cut back and steam used expansively, regulating the cut-off to meet the requirements of the service. The locomotive as designed would be unable to get rid of the steam fast enough to prevent back pressure and the engine would be choked with steam. As the back pressure increases the mean effective pressure would be diminished and result in a loss of power and speed.

73. Weight on Drivers and Tractive Effort.-"Does the term 'weight on drivers' mean also the weight of the drivers, journals and pin connections in figuring the tractive effort? If not, why not? Why, in only one side of the engine instead of figuring the tractive effort, do you take both cylinders?"-W. L. G.

Answer. The adhesion of a locomotive is the friction between the driving wheels and rails and depends upon the weight or pressure of the surfaces in contact. Therefore, the weight on the drivers means the weight of the driver and the load resting on it at its point of contact with the rail. The weight on drivers is usually limited by the engineering department and depends on the weight of the rails, condition of the road bed, strength of the bridges, etc. If the weight of the drivers was not included in placing the limit, the engine would be hard on the track and increase the cost of maintenance of roadway and bridges. A pair of drivers will weigh from 6,000 to 9,000 pounds, and as they add to the adhesion, it should be figured from the point of contact with the rail. The use of the dynamometer car is the most accurate method to obtain the drawbar pull or tractive power of a locomotive. This is a car specially fitted with a drawbar connected with calibrated springs that indicate the number of pounds pull on the drawbar. The answer to question No. 63 in the March issue gives the formula referred to in this question and is usually employed in figuring the tractive power as it meets the requirements. In answer to question No. 63 we found a tractive power of 22,674 pounds for an 18x26-inch engine with a 60-inch wheel and 190If we desire to pound boiler pressure. obtain the tractive power by figuring both pistons or both sides of the engine, the following formula should be used instead, which gives nearly the same results. To make the example clear to all we will give the figures. Area of one piston (which

=

pounds) times twice the length of the stroke (which 4.3333 feet) times 2 (for both pistons or both sides of the engine), divided by the circumference of the wheel, equals tractive power of 22,685 pounds. A slight difference, but either is accurate enough for general application and the one cylinder method is the shortest, therefore most used in calculation. If the weight on the drivers is known, one-fourth of the weight is usually taken as the tractive power. In the above, would expect the weight on the drivers to be about 91,000 pounds.

"As a matter of information will say that this train was run and had orders to run 8 hours late by first trick dispatcher and while on the road another dispatcner came on duty and run them extra from where they were and did not annul No. 53."-J. D. M.

Answer. We believe the general understanding of this situation is that No. 53 is due to be on the road when the time table takes effect. The first trick dispatcher would therefore be correct in his action. Perhaps the second trick man had no occasion to annul the train, but we think it would have been necessary if he did not want the schedule in effect on Sunday.

This answer is based on the supposition that Standard Rule 4 (B) is in use.

m.

85. Another Time Table Question.-"You have orders to run extra Howells to Winder. No. 22 of January 22d is annulled. No. 22 is due to leave Howells at 6 p. You arrive at Winder 11:45 p. m. and ask for running orders to Shops. January 23d, at 12:01 a. m., a new time table takes effect and on the new time table No. 22 is due to leave Winder at 12:05 a. m. The dispatcher says to wait until 12:05 a. m. and represent No. 22 on the new time table. Winder is a registering point and a terminal for local freights. Can you represent No. 22 of January 23d?"-J. D. M.

Answer. As we understand the situation it is this. No. 22 is scheduled from Howells to Shops and if that schedule had not been annulled on the 22d there would have been no question as to its being in effect on the new time table. The question is, therefore, whether, on the taking effect of the new time table, No. 22 can be considered as due to be on the road. We are compelled to admit that we do not know. We presume that arguments could be brought forward to support either side of the question. If we were concerned in the movement of this train we should take the safe side, and we think that would be for the dispatcher to put out an order reading as follows:

"No. 22 due to leave Winder at 12:05 a. m., January 23d, is annulled Howells to Shops."

Possibly we do not correctly understand the question. If so, we shall be glad to hear further.

86. Who Takes the Siding?-"We were on extra 1379 and would like to know who is entitled to main line at D on the following orders:

"Order No. 1 (received at B): "Extra 1379 east will take siding and meet extra 338 west at C."

"Order No. 2:

"Extra 1379 east will meet extra 338 west at D instead of C."

"East bound trains of all kinds have right of track over all trains of same class. Does the first part of Order No. 1 still hold good at D, or is the whole order superseded by Order No. 2?—F. R. S.

Answer. We have heard this question raised before. It has been argued that the second order changes the meeting point only and does not affect the clause directing extra 1379 to take the siding. Our opinion, however, is different. The provision for extra 1379 to take the siding is dependent on the other part of the order, which is to meet extra 338 at C. The first clause has no meaning except in conjunction with the second, and we think that when the second clause is made void, the first one is also. If we are correct in this, extra 1379 would hold the main track at D.

Since there is evidently a doubt in re

gard to such an order, we think it a good subject for decision by the proper officer.

Note. A correspondent from Missouri sends us the following:

"Enclosed find copies of train orders in use on the Frisco System. I send these in compliance with request in the February Firemen's Magazine. We are using the Standard Code with a great many variations, but there is no provision made for a subsequent order directing a train to run so much later than the time given in a previous order."

The request referred to was under the head of "Schedule for Delayed Trains," on page 152 of the February Magazine, and the orders attached are in the same form as those quoted in that article. They contain the names of a dozen stations and the time is intended to be used by trains in both directions.

He says there is no provision made for running the train so much later than the time specified in the order. We can not help but wonder what the dispatcher would do if he found that the train would be 15 minutes later than he first thought. Would he send another order, containing times at the 12 stations? We know how much time that would take. We should rather say, "No. 2 will run 15 minutes later than Order 34." Why not?

Who else will give us more light on the subject?

Driving Boxes and their Lubri

cation.

MR. R. P. BLAKE (Northern Pacific Ry.) In connection with this subject there is one point which has not been brought up, and that is the use of hard grease for lubricating the driving boxes. My attention had not been called to it, until within the last few weeks, and I have found that the Michigan Central Railroad has been using hard grease for lubricating the driving boxes with what they claim excellent results. I have not had any opportunity of going into it to find out exactly what they have accomplished, but in a general way I understand that they get fully twice as good results as with the oil. It is much more reliable, and does not require anywhere near the attention. The method is to fit the cellar close up against the side

of the journal and fill the cellar with grease; in the bottom of the cellar is put a plate or block that fills in completely, with a spring underneath it which keeps the grease pressed up against the axle. Between the axle and this grease they put a fine wire netting. I would be very glad to know whether anybody in this room has had any experience with a box of that kind, and whether they know anything further about it.

PROF. KAVANAUGH (University of Minnesota): I have never had any experience with grease as a lubricant for locomotive driving boxes, but I have seen a description of a scheme which is being used on the Delaware, Lackawanna and Western Railroad for lubricating both driving and truck axles with grease.

They have a box-you might call it an auxiliary cellar-made of about No. 16 steel. The top of this box, which is