Buckets taken full. Buckets continuous. 1 lb. of coal 34 cu. in.

ELEVATING CAPACITIES OF MALLEABLE IRON BUCKETS Table gives tons (2,000 lb.) of pea coal per hour at 100 ft. per min.

coal pea

=

5.65 4.71 4.04 3.53 3.14 2.83

8.39 6.99 5.99 5.19 4.66 4.19 3.81
11.34 9.45 8.10 7.09 6.30 5.67 5.15 4.72
17.19 14.73 12.88 11.46 10.31 9.38 8.59
22.88 20.02 17.80 16.02 14.56 13.35
20.56 18.28 16.45 14.95 13.71

Weight of 1 cu. ft. of 53.5 lb. 32.3 cu. in., or .0187 cu. ft. 1 lb. CONVEYING CAPACITIES OF FLIGHTS AT 100 FT. PER MIN. (Tons of Pea Coal per Hour)

NOTE. These ratings are for continuous feed. 2,000 lb. = 1 T.

PITCH AT WHICH ANTHRACITE COAL WILL RUN, IN INCHES PER FOOT

Depth ba in Ft.

HORSEPOWERS FOR COAL CONVEYORS (COAL INCLUDED) Speed, 100 ft. per min. Conveyors, 100 ft. long. Standard steel troughs.

HORIZONTAL PRESSURE EXERTED BY BITUMINOUS COAL AGAINST VERTICAL RETAINING WALLS PER FOOT OF LENGTH

1234567

10 40

90

50 28 4,993 350

7,840 550

102.0

45.0

8

159.0 57.0
229.0 70.0
312.0 83.0
407.0

96.0

10

11

12

160 70 29 5,358 363 250 90 30 5,733 376 360 110 31 6,122 389 490 130 -32 6,523 401 640 150 33 9 516.0 108.0 810 170 34 637.0 121.0 1,000 190 35 770.0 134.0 1,210 210 36 917.0 146.0 1,440 230 37 13 1,076.0 159.0 1,690 250 38 14 1,248.0 172.0 1,960 270 39 15 1,433.0 185.0 2,250 290 40 16 1,630.0 197.0 2,560 310 41 17 1,840.0 210.0 2,890 330 42 18 2,063.0 223.0 3,240 350 43 19 2,298.0 236.0 3,610 370 44 20 2,548.0 248.0 4,000 390 45 21 2,809.0 261.0 4,410 410 46 22 3,083.0 274.0 4,840 430 47 23 3,369.0 287.0 5,290 24 3,669.0 299.0 5,760

25 3,981.0 312.0 6,250 490 50

15,925

631 25,000 990

Weight of coal=47 lb. per cu. ft.

HORIZONTAL PRESSURE EXERTED BY ANTHRACITE COAL AGAINST VERTICAL RETAINING WALLS PER FOOT OF Length

8

244.50 88.02 352.08 107.58 7 479.22 127.14 625.92 146.70

924.30

952.70

910.08 213.30 33 10,650.0 635.70 15,486.0 9 792.18 166.26 1,151.82 241.74 34 11,306.0 655.26 16,439.0

981.19

10 978.00 185.82 1,422.00 270.1835 11,980.0 674.81 17,420.0 11 1,183.38 205.38 1,720.62 298.6236 12,675.0 694.39 18,429.0 1,009.60 12 1,408.32 224.94 2,047.68 327.0637 13,389.0 713.94 19,467.0 1,038.10 13 1,652.82 244.50 2,403.18 355.50 38 14,123.0 733.50 20,533.0 1,066.50 14 1,916.88 264.06 2,787.12 383.94 39 14,875.0 753.07 21,629.0 1,095.00 15 2,200.50 283.62 3,199.50 412.38 40 15,648.0 772.63 22,752.0 1,123.40 16 2,503.68 303.18 3,640.32 440.8241 16,440.0 792.20 23,904.0 1,151.80 17 2,826.42 322.74 4,109.56 469.2642 17,252.0 811.74 25,084.0 1,180.30 18 3,168.72 342.30 4,607.28 497.70 43 18,083.0 830.73 26,293.0 1,208.70 19 3,530.58 361.86 5,133.42 526.1444 18,934.0 850.86 27,530.0 1,237.20 20 3,912.00 381.42 5,688.00 554.5845 19,804.0 870.41 28,793.0 1,265.60 21 4,313.00 400.98 6,271.00 583.2646 20,695.0 889.99 30,090.0 1,294.00 22 4,733.50 420.54 6,882.50 611.46 47 21,605.0909.54 31,412.0 1,322.30 23 5,173.70 440. 10 7,522.50 639.90 48 22,533.0 929.10 32,763.0 1,350.90 24 5,633.30 459.67 8,190.70 668.3549 23,482,0 948.66 34,143.0 1,379.40 25 6,112.60 479.22 8,887.50 696.79 50 24,450.0 968.21 35,550.0 1,407.90

COST OF UNLOADING COAL

Coal is generally unloaded from railroad cars into the hold of a vessel by some form of unloader, which usually raises the car bodily and dumps it directly into the hold of the vessel. In this way the cost of unloading has been reduced to a very small figure, and the speed of unloading greatly increased. The cost of unloading is given by the makers of the Brownhoist as varying from 2 c. per T. up to 44 c. per T.; deducting in each case 2 c. for

trimming the coal in the vessel, the actual cost of loading varies from

c. to

2 c. per T., depending on the conditions. Along the Lakes it is customary to pay a premium ofc. per T. to all connected with the loading, for all coal loaded in excess of 2,500 T. per day and 1,800 T. per night. The Brownhoist has a guaranteed capacity of at least 300 T. per hr., but this has been greatly exceeded in practice. The McMyler end dump has a record of 4.65 T. per min., and the McMyler side dump of 8.41 T. per min. These figures apply to the lake cities of the U. S.

The C. W. Hunt Co., West New Brighton, N. Y., gives the following figures for handling coal along the Atlantic seaboard: The cost of shoveling coal by hand in the hold of the vessel into ordinary iron buckets is about 6 to 7 c. per T. of 2,000 lb.; the cost for iron ore, phosphate rock, or sand, about 10% less. The cost of shoveling coal and hoisting it out of vessel to the wharf with an ordinary hoist with manila rope is 12 to 13 c. per T., so that the hoisting costs about the same as the shoveling. The cost for both shoveling and hoisting with a steam engine is 10 to 11 c. per T. The cost when using a steam shovel or grab bucket for taking up coal out of the vessel varies greatly in different classes of vessels, but usually runs from about 1 to 5 c. per T., averaging about 3 c. After the coal is hoisted, it can be carried into storage with an automatic railway or other efficient plant, at a cost of about 1 to 1 c. per T. For great distances, a cable railway or a conveyor can be used, which handles the material about as cheaply as for short distances, but the cost of plant is greatly increased.

In unloading anthracite from cars on a trestle into pockets or on the ground, the loss on all sizes is 2 to 3% when the coal is not resized; when it is resized the loss is 8 to 9%.

The cost of stocking and unloading given by Mr. Piez, as follows:

anthracite by the

Dodge

system is

Machines Employed.-Fuel, fuel dust, and other products may be briqueted by a number of different styles of machines, but all these may be divided into two classes, briquet and eggette machines. The eggette machines have a pair of rollers, the faces of which are provided with semispherical or semiovoid depressions. The material that is fed between these rolls crowds into the openings of the two rolls, thus forming small nodules. The material is mixed with a suitable binder before being fed to the rolls, and the eggettes are received on any suitable form of traveling belt or chute and removed for drying or storage. This style of machine has not been used to any great extent in this country. The briqueting machines all act more or less on the principle of the brick machine, having some kind of a die or mold into which the material is crowded. The material is either pressed as it is being fed into the mold or subsequently by some form of plunger. For some materials, common brick machines, such as are used in the manufacture of building brick, are employed, while in others special forms are necessary.

Briqueting of Fuel.-Fuel briquets have not come into general use in the United States for two reasons: (1) on account of the great amount of cheap fuel available, which has prevented the utilization of culm, coal dust, etc.; and (2) on account of the lack of or high price of suitable bonding material. This latter condition is now being removed by the introduction of byproduct coke ovens, from which supplies of coal tar can be obtained. Aside from peat and certain kinds of brown coal, and possibly some caking coals, it is neces