March 8, 1918. THE COLLIERY GUARDIAN 485 The system of conveying may be described as consist- ing of a series of chains in troughs cast of special hard cast iron. The bottom of the trough is f in. thick, and the side J in. thick. The cross conveyor is 38 ft. long, and is placed immediately beneath the bottom of the bunker which receives the coal. The coal passes to this cross conveyor through shoots with adjustable cut-off slides, and, after being partly elevated, is delivered on to the main inclined elevator- conveyor, which is 106 ft. long. This runs at an angle of 30degs., and raises its load through a height of 40 ft. The fuel is then delivered on to the main dis- tributing conveyor, which runs the full length of the Si I s & ' ... ■< a A -'4 Low - Fig. 3.—Rotary Truck Tipplers. Rail Level Rai! Levef Fig. 4.—Longitudinal and Cross Sections of Rotary Truck Tippler. overhead storage bunkers. The bottom of the dis- tributing conveyor is fitted with openings and cut-off slides at intervals of 3 ft., by which means the fuel can be delivered at any of the bunkers above the boilers. The length of this conveyor, with its exten- sion, is 395 ft. Each section of the conveyor system is driven by means of a separate motor through substan- tial spur wheel reduction gear. A somewhat similar plant, though on a much larger scale, was recently erected to the order of H.M. Government. In this case the plant serves a range of 32 Lancashire boilers, each fitted with “Bennis” mechanical stokers and compressed air furnaces. Storage is provided for about 2,240 tons of coal, and the coal is transferred from the railway trucks to the storage bunkers at the rate of 60 tons per hour. The plant is capable of transferring the coal from the bunkers to the stokers at the rate of one ton per boiler per hour. The full railway trucks are pushed by the locomotive into a rotary truck tippler, which, as in the previous case, revolves through a complete circle, so that the trucks are turned upside down and completely emptied without raking or trimming. The clamping gear which holds the trucks in position is adjustable, so that the tippler can take any height of truck up to the maxi- mum size for which it is designed. The tipple revolves on rollers, which are driven, through suitable worm-and-spur reduction gear, by an electric motor of about 6 b.h.p. The tippler can dis- charge about eight to 10 trucks per hour, and the com- plete revolution occupies about two minutes, the remainder of the time being taken up in entering the full truck into the tippler, clamping it down, and removing the empty truck. As the coal leaves the trucks it falls into a receiving hopper built of concrete, below the rail level, and holding about 20 tons of coal, from which it flows by gravity through a shoot into a U-link steel chain conveyor. In this particular case the coal is supplied to the stokers by “Bennis” independent elevators, one for each boiler, so that each boiler with its elevator forms a separate unit, and can be put into or out of service without interfering with any of the other boilers. Another type of truck discharge plant is that by which standard railway trucks are emptied by allow- ing the coal to flow by gravity through the end door of the truck. It consists of a massive ram, on one end of. which a crutch is fixed, which engages with the rear axle of the truck. (Fig. 5.) The ram is raised and lowered by a screw thread. A similar thread is cut in the hub of a phosphor-bronze worm wheel, which is turned by a mild steel worm- operated through spur reduction gear, from an electric Fig. 5.—Tilting End Tippler. motor. The worm wheel and worm are contained in an oil bath, which oscillates, on trunnion bearings, in order to allow the top of the ram to move sideways and follow the path of the truck axle, as it rises. The front wheels of the truck, which do not leave the track, can be chocked in position. When the tippler is not in use, the ram is berthed, in a vertical position, in a pit beneath the ground. About 5 b.h.p. is required to raise a full 10-ton truck, and the tippler can be arranged to drive by a belt from adjacent shafting, if electric power is not available. THE PEN-HSI-HU COLLIERIES, MANCHURIA.* By C. F. Wang. Pen-hsi-hu, which is about 45 miles south-east of Mukden, was well known, 200 years ago, for its coal and iron industry, but owing to underground water the coal mines progressively declined from about 1875 till the Russo-Japanese War. After the war, in October 1905, Count Okura began to re-open the aban- doned coal deposit. It was worked without Chinese permission for several years, and ultimately the Pen- hsi-su Coal and Iron Company Limited was formed, which at present has coal mines producing over 1,000 tons of coal per day, limestone quarries, a coal wash- ing plant, a coking plant of about 300 tons daily output, a blast furnace of 150 tons capacity, and an iron mine at Miao-er-kou producing about 300 tons a day. Geology. The coal formation occupies an area of about 3,400 acres between the Cambrian rocks and the tertiary strata, with the igneous rhyolite-porphyry at the eastern corner. The latter disturbed the formation a good deal by tilting and faulting. The limestone at the north extends under the coal formation, dipping from 20 to 50 degs. south-south-east. At Pen-hsi-hu the upper part of this coal formation has been cut away by a stream joining the Tai-tsu-ho at the south, forming the valley of Pen-hsi-hu. The formation con- sists of sandstone, sandy shales, shales, and coal beds, interbedded, of various thicknesses. It extends over three miles south. At the western boundary of the limestone the hills attain their highest elevation, about 1,800 ft. above sea level, and outcrops of coal are noticeable. The formation may be divided into three fields, with sandstone as cover, then shale and sandstone interbedded, and under that limestone of crinoidal origin. The coal formation re-appears again at Chien-chan-tse, after having been cut through by the igneous rhyolite-porphyry, and at Mao-tsu-yu, to the east, forms another coal basin. The western area, extending from Sin-tung-kou to Ho-tung-kou, lying above the Cambrian rocks, amounts to 2,893 mou, or 444 acres, area, and has from 25 to 40 ft. total coal. There are many old inclined shafts, and the dip is about 25 degs. to the south-east. The Liu-tong area has about 1,135 acres (7,390 mou), and 38 ft. of coal; while the Pen-hsi-hu area has about 1,825 acres (11,900 mou), and 38 ft. of coal. The dip is about the same as in the western area. The total estimate for this 40 ft. of coal in the 18 beds of the three regions is about 225,650,000 metric tons. Minus 17,992,000 tons reserve, and on the basis of 60 per cent, recovery, for 1,000,000 tons a year production, there is a reserve for at least 120 years. Mr. S. S. Loh, according to a recent estimate, after careful study, gives the conser- vative estimate of over 123,000,000 tons (as shown in Table 1.), considering the coal beds at the average Table 1.—Coal Area and Tonnage Acres. PeaS To“' Upper. 744 ... 1,230 ... 4,030,500 401 ... 783 ... 3,353,562 425 ... 813 ... 3,496,056 479 ... 873 ... 3,570,732 1,318 ... 2,636 ... 11,963,964 3,367 ... 6,335 ... 26,414,814 at Pen-hsi-hu. Tonnage. Upper seams. Pen-hsi-hu ...... 486 ... S-yen-kou..... 382 ... Liu-tang ........ 388 ... Sing-ton ........ 394 ... Vertical shaft... 1,318 ... Total...... 2,968 ... Lower. Total. ... 21,515,593 ... 25,546,093 ... 11,454,511 ... 14,808,073 ... 12,282,175 ... 15,778,231 ... 13,565,800 ... 17,136,532 ... 37,695,886 ... 49,659,850 ... 96,513,965 ...122,938,779 thickness of 25 ft. He divides the coal into five regions, and each region into two sections, upper and lower, the former 6 ft. and the latter 19 ft. in thick- ness. Table 2 is taken from Kao Long’s book, which Table 2.—Thickness Seam. Pen-h Ft. Pao-cha ............ 7* Siang-tuan........... 4 Chou-tuan ....... 3 I-Chieh (No. 1) .... 7* Erh-Chieh (No. 2)... 5* San-Chieh (No. 3)... 4 Ssu-Chieh (No. 4)... 3* Wu-Chieh (No. 5)... 4 * Coal hard and lumpy, whiJ part easily crumbled to dust. Coal Seams in Feet. t At At si-hu. Liutong. Shintong. in. Ft. in. Ft. 0 ... 7* 0 6* 5 ... 4 5 5 5* ... — 5 0 ... 8* 0 7* 0 ... 8* 0 6* 0 ... 4 0 3 0 ... 4 5* 3* 0 ... 4 0 5 n the rest are for the most gives in a general way the thickness of each seam as found near the surface. Mr. Loh has found that these seams decrease a good deal in depth. Owing to intrusion by the igneous rock at the north- east, at Tou-shan, and faults in the limestone at the west, the coal formation is much disturbed. As a result of the many faults and folds, the coal is of a semi-bituminous nature. The sandstone cover, of good-sized grains, is yellowish-white in colour, and is good for rough building purposes. The shale is from very dark to light in colour. This is the great Nan- fen shale, as it appears most prominently at Nan-fen, 17 miles south-west of Pen-hsi-hu. The coal formation has a total thickness of 500 to 550 ft., with 18 seams of coal; eight of them are workable. Under this coal formation is sandstone again, some 20 ft. in thickness, then 20 ft. of shales; thus connecting up with the crinoidal limestone, which appears at Lun-shan-tsu, east of the company’s land. The rhyolite-porphyry is dark grey in colour, and is hard, with orthoclase, hornblende, microcline, and quartz. Outcrops of coal call be seen on Lun-shan-tsu hill and to the west of Pen-hsi-hu station. Coal Mining. There are three coal mines at Pen-hsi-hu. A fourth was abandoned on account of excessive water. They are all worked to the dip of about 20 degs. Levels are established 262 ft. apart, along the incline, or about 110 to 130 ft. vertically. No. 1 pit was first started in April 1906 on the Chou-tuan seam, which has the Pao- cha and Siang-tuan seams above it, a total of about 15 ft. coal. Three inclined shafts were simultaneously sunk for this No. 1 pit for haulage, drainage and * From a paper read before the American Institute of Mining Engineers.