METHOD OF INSTALLING BABCOCK & WILCOX BOILERS IN THE S. S. "KVICHAK" While the vessel was still on the stocks, an opening was left in the side opposite the boiler space. The boilers were raised on crib work, and slid through the opening on to their foundations, after which the frames were erected and the plating completed.

COAL CONSUMPTION TESTS OF S. S. "JOHN W. GATES"*

Between October 10 and 15, 1900, tests were made on the lake steamer "John W. Gates," owned by the American Steamship Co., by Lieutenant-Commander J. H. Perry and Lieutenant B. C. Bryan, U. S. N.

Four tests in all were made, of ten, four, eight and six hours' duration, respectively. During the tests indicator cards were taken from the main engines, and the usual observations of pressures and temperatures recorded. The coal was carefully weighed and logged on each test.

Tests Nos. I and 2 were made with the vessel light, on the up trip, in Lakes Huron and Superior, respectively. Test No. I was made under the usual running speed of the vessel when light, and amounted to merely weighing coal and taking observations for ten hours out of the run. Test No. 2 was made using a steam jet in the smoke pipe to increase the draft.

Tests Nos. 3 and 4 were made on the down trip, after having loaded at Two Harbors, Minn., with about 7000 tons of ore, the vessel drawing about 17 feet 10 inches of water. Test No. 3 was made at the usual running speed, and Test No. 4 with draft increased by steam jet in smoke pipe.

The machinery of this ship was built under the supervision of the Chief Engineer of the American Steamship Co., Mr. Joseph F. Hayes, and the great economy obtained is largely due to his care in the design and arrangement of the plant. The ratio of the high to low-pressure cylinder area is 1 to 13.22. Joy valve gear is used on the high and intermediate-pressure cylinders, giving in the high-pressure cylinder an admission of steam almost perfect, as is shown by the indicator cards therefrom. The cylinder ports are made large, while the clearance is reduced as much as possible. A feed heater is provided, into which all the auxiliaries necessary for heating the feed water are exhausted. The dynamo when running exhausts into the third receiver of the main engine, and all precautions have been taken to make these engines economical, and with great success, as is shown by the results.

The type of Babcock & Wilcox boiler adopted, known as the "Alert" type, is one that the recent tests made by Government officials show to be exceedingly economical under various conditions. It is provided with baffle plates directing the products of combustion three times across the tubes before leaving the boiler. Each of the two boilers installed is 10 feet long, II feet 8 inches wide, and 13 feet 10 inches high, containing 3000 square feet of heating surface and suitable for 65 to 70 square feet of ordinary grate surface for hand firing. The total grate surface of all stokers is 108 square feet.

The weight of the two boilers dry is 109, 260 pounds, and with water, 132,590 pounds.

The bottom and top rows of tubes are 4 inches in diameter and all others are 2 inches in diameter. All tubes are of seamless cold-drawn steel, the 4-inch tubes being No. 6 B. W. G., and the 2-inch tubes No. 10 B. W. G. in thickness. The lengths between headers is 9 feet.

The main propelling engine is of the vertical, direct-acting, inverted, jetcondensing, quadruple-expansion type.

* Extracts from Journal of the American Society of Naval Engineers, vol. xii.

Order of cylinders from forward: (1) high-pressure, (2) first intermediatepressure, (3) second intermediate-pressure, (4) low-pressure. Sequence of cranks: high-pressure, low-pressure, first intermediate, second intermediate.

The high-pressure and first intermediate-pressure are at 180 degrees, as are the second intermediate-pressure and low-pressure, the former being at 90 degrees with the latter.

There is one four-bladed propeller, 14 feet in diameter with 15 feet 6 inches pitch.

Two mechanical stokers of the Crowe pattern were fitted to each boiler. This stoker consists, essentially, of a set of bars carried from front to back of the furnace, over a number of fair leaders, by two chains, one on each side of the furnace. At the back of the furnace the chains and bars pass over a drum and thence back over fair leaders to the front of the furnace again.

During the entire trip the stokers worked satisfactorily. During most of the time little or no smoke was emitted from the pipe except while the fires were being worked from the back, or when an additional amount of coal worked in under the plate in the front of the furnace. The air pump worked regularly and quietly, but for some reason, probably due to the large clearance required in the cylinders of this type of pump, the vacuum carried was not much in excess of 231⁄2 inches.

Lead did not melt during any of the tests when suspended in the up-takes just over the top row of 4-inch tubes or practically where the gases leave the boiler proper.

Lead suspended in the boiler where the gases leave the last row of 2-inch tubes melted on the test of October 15, but only softened on the tests of October 10 and 13.

A proximate analysis of the coal used, gave results as follows:

The following table gives the data and results of the tests:

*The increase in coal consumption per indicated horse-power is caused by the waste of steam due to increasing the draft by means of a steam jet in the funnel. This jet was supplied by a 12-inch pipe and nearly doubled AUXILIARIES IN OPERATION: Air pump, feed pump, stoker engine and dynamo engine part of time, as noted

the draft.

above.