1030 THE COLLIERY GUARDIAN. June 1, 1917. _________________________________________________________________________________________________________________________________________________________________ gate in this deck by a properly designed chute into the slack car. The nut passing over the slack screen (on the middle deck) is delivered down the sloping plate gently on to the bottom deck in front of the slack gate and passes through the nut gate on to a loading boom, by which it is lowered carefully into the car on the nut track. The balance of the coal—all the sizes above the nut— is now picked on the top deck, after which the egg coal is removed by the egg screen and delivered by the loading boom into the car on the egg track, while the lump coal passing over the egg screen is lowered by the sloping plate on to the bottom deck and passes out over the end of the Marcus screen on to the loading boom, by which it is carefully lowered into the car on the lump track. Any combination of sizes, such as nut and slack in the nut car; egg and nut, or egg, nut and slack in the material so there would be a minimum interference with the old, and at the same time serve every purpose for which it was intended. The new equipment (fig. 5) has several unique features. The use of the “ Petersen ” pendulum hanger, carried by cast iron stands, gives the screen a decided vertical as well as horizontal stroke. This helps to clean the coal, and causes it to flow easily over the 15 degs. lip screens. The successful operation of a single-leaf screen of this size, it is believed, is without precedent, this also being made possible by the use of the pendulum hanger, which reduces the driving- rod stress to a minimum. Two chain drives operate the feeder plate and retarding conveyor. The problem of replacing the old wooden shaker shed by a new steel one on the same centre line was solved by erecting the new structure on the down-track side of the old, on a temporary foundation, and later moving it into place. Plenty of heavy timber cribbing was available SOUTH WALES INSTITUTE OF ENGINEERS. An ordinary general meeting of the South Wales Institute of Engineers was held at Cardiff on Friday, May 25, under the presidency of Mr. Hugh Bramwell. The following were elected to the institute;—As members : John M. Draper, Bridgend ; David T. Evans, Loughor, Glam.; Walter W. Hannah, Penarth ; Thomas S. Price, Cardiff; and Daniel D. Williams. Gowerton, Glam. As associate members: Hugh L. Francis, Cardiff; Stanley Jenkins. Hopkinstown, Glam. Aerial Wire Ropeways. Mr. J. W. White, the author of the paper on aerial wire ropeways, read at the March meeting,* displayed on FEEDER HOPPER CAR' ■■■Slack Screen Slack Chute < S ack Chute Too of Rail r fr Fig. 3.—Diagram of Tipple with Inclined Lump Loading Boom A= Slack, Bar Screen Lump, ROM. B= Nut, Nut and Slack C= Egg, Egg and Nut, Egg Nut and Slack D=Lump, Egg Lump, Egg Lump Nut, R.O.M. RECIPROCATING EEDER ‘ Boiler Coal Conveyor____ Egg Loading Boom ■Nut Screen . Egg Screen PIT BOILER COAL . BIN ...-WEIGH ^BASKET Lump and Egg Loading Booms ^.. _ 1 i \\ Lump and Egg Mmg Tables-' B the lantern screen and explained the features of typical installations of ropeways. A Top of Rai! End View of Tipple 0 Shaker Screen 1 . 1 I l REFUSE BIN Box car Refuse Trough Chute- [SHAKING rTs_ Egg anti Nut Egg Nut and Slack Lump Lump and Egg Lump Egg and Nut ROM. NUT SHAKING LOADER _______________ Nut Nut and Egg Slack Shaking Screens. ^Coal Conveyor Fig. 4.—Tipple with Marcus Screen and Picking Table. egg car and all combinations up to run-of-mine in the lump car may be made on this horizontal screen by simply closing certain valves in the bottom deck. This feature of the screen does away with the cumbersome and noisy cover plates which were formerly used on shaker screens for accomplishing the same result. An extra valve is placed near the outer end of the screen which may be opened to deliver lump or any combination of coal up to run-of-mine into a chute _ passing beneath the load- ing boom and into a box car on an outside track. This permits the box car to be placed, the box-car loader put into position, and then, by opening the -gate referred to above, coal is immediately de- livered into the car with- out the usual delay occasioned by the use of the box-car loader. When the box car has been loaded, the gate de- livering coal to the box- car chute is immediately closed and loading over the boom into an open car is resumed until the loaded box car has been replaced by an empty with the box-car loader inserted, ready for an- other operation. By this arrangement, box cars may be loaded without in any manner cutting down the capacity of a mine, which is one of the chief objections to Fig. 5.—Benham Tipple. Upper Screen, Dump Hopper and Chute. .r . loading coal into box cars with a loader. The Marcus screen, being horizontal, saves several feet in the height of a tipple. This varies from 8 to 14 ft., depending on whether it is a 2-, 3- or 4-track tipple. The entire construction of the tipple is also much simplified, since all the moving machinery for both screening and picking are combined in the drive gear, which is placed on a concrete pier at the rear of the screen. The screening equipment at the Benham Colliery, in eastern Kentucky, has recently been replaced by new and complete plant. In the old tipple, coal was dumped from mine cars with lifting end gates over a Jeffrey-Griffith patented dump, chuted into an 8-ton hopper with a 30 degs. pitch bottom, the pitch being at right angles to the centre line of dump track. It was then fed by means of a small plate feeder to a 15 by 36 in. flight retarding conveyor, which lowered it on a 26 degs. slope to a point midway between the dump and the railroad tracks at the foot of the hill Here the coal was either screened and the slack passed to the crushers and thence to a 500 ton slack bin, or by means of a gate in the screen run-of-mine coal could be delivered to the crushers. Normally, the coal passing over this screen was lowered by a retarding conveyor of the same type as the one mentioned above to a set of shaker screens at the track level, where egg and block coal were loaded for market, and the degradation elevated to the crusher bin by a 6 by 12 in. flight conveyor. The two most undesirable features of this arrange- ment were the inadequate facilities for handling a large tonnage of egg and block coal with minimum breakage and the necessity of a mechanical means of carrying mine-run coal from dump to crusher bin. To remedy these defects considerable new machinery was required, and care was given in locating the new for building this temporary foundation, the principal difficulty being to so locate the cribs as not to foul the track clearance which had necessarily to be maintained nor the old wooden structure. Combined wood and steel tracking was laid on timber mud blocks, and between the two sets of tracking 2T’si n. solid rollers were placed. These rollers were cut from worn-out mine-car axles. To transmit the column load to the tracking, 10 in. and 12 in. steel channels were used, the computed stress in these channels being less than 16,0001b. per sq. in. under full load.—Coal Age. Bristol Channel ports ........ 108,693 ... 99,533 North-western ports .......... 187,189 ... 190,098 North-eastern ports .......... 413,839 ... 521,300 Humber ports ................ 75,945 ... 46,840 Other east coast ports ........ 4,962 ... 590 Other English ports .......... 3,085 ... 2,853 Ports on east coast of Scotland 42,571 ... 44,349 Ports on west coast of Scotland 131,559 ... 152,589 Total 967,843 . .. 1,058,152 Bunker. April 1916. Tons. April 1917. Tons. Bristol Channel ports 11,227 8,722 North-western ports 45,159 40,612 North-eastern ports 32,839 25,206 Humber ports 9,051 3,987 Other east coast ports 12,164 4,747 Other English ports 2,504 2,605 Ports on east coast of Scotland... 7,796 6,411 Ports on west coast of Scotland... 18,252 28,624 Irish ports 2,637 2,116 Total 141,629 .. 123,030 The shipments to English and Welsh ports aggregated 667,262 tons (last year 583,675 tons), to Scottish ports 25,755 tons (last year 47,605 tons), and to Irish ports 365,135 tons (last year 336,563 tons. Mi'. White also lead a supplementary paper, dealing with ropeways for hauling timber in forests (see p. 1033). DISCUSSION. Mr. W. Thorneycroft, Glasgow, wrote a memo- randum on a ropeway erected by Mr. White for him at Plean Colliery about two years ago. The total cost, without hauling and carrying ropes, was £2,360, which comprised a 9 in. by 13 in. stroke engine driving the rope, all foundations, a 50-ton hopper above the loading terminal, a mechanically-driven tippler to enipty the dirt hutches into the hopper, and 420 yds. of ropeway, including the terminals, all complete and in working order. The outside terminal, which carried the return wheel, was 150 ft. high. The quantity of dirt handled was about 1,000 tons per week. The speed of the rope was about 200 ft. per minute, and 13 or 14 buckets, carrying about 7 cwt. each, were in circulation. At present it was not necessary to work the ropeway continually. Since the ropeway stai ted it had handled about 106,500 tons of dirt, two-thirds of which came from the washer and the remainder from the pit.. Three- fourths of the dirt from the washer would pass through a f in. square mesh. The colliery and plant worked on the day shift only. The ropeway required the constant attendance of one man and a boy. and, of course, a certain amount of ' attendance from the repairing staff of the colliery. Before the ropeway started, the work constantly employed eight men, three boys and three ponies, and generally each morning three additional men for two hours or more, to tip the dirt filled by the night shift repairers in the pit, weie necessary to haul and tip the dirt from the place, where it was now taken charge of by the ropeway plant and attendants, and this cost was growing as the bing extended. In addition to the direct saving in labour effected by the ropeway, there was a very great advan- tage in the prompt return of empty dirt hutches to the shaft, especially in the early hours of winding. The bunker holding 50 tons provided the necessary elasticity between tipping power and winding, and allowed the dirt hutches to be emptied as quickly as coal. The following are the details of the cost of working up to date, estimated as closely as possible, and including 13 per cent, per annum for interest and depreciation on the plant:—■ ___________________________ Coal Shipped from Ports in the United Kingdom during April.—The following figures, which have been extracted from the returns issued by the Commissioners of H.M. Customs and Excise, show the quantities of coal shipped from each group of ports in the United Kingdom during the month of April, as compared with the corresponding month of 1916 Cargo. April 1916. April 1917. Tons. Tons. £ Per ton. d. Wages of constant attendants 335 or 0'76 Ropes 295 „ 0'66 Ordinary supplies, oil, etc., and repair wages 72 „ 016 Steam at lOd. per 1,000 lb Special repair due to the shifting of 75 ft. 69 „ 0'15 tower Interest and depreciation at the rate of 51 „ on 13 per cent, per annum 637 „ 1'44 Total £1,459 „ 3'28d. With the old system for the same period Mr. Thorney- croft estimated that the cost would have been £2,105 for wages and ponies, and about £150 for wastage and upkeep of hutches, &c., in all £2,255, or 5'09d. per ton. Both these cost figures were high owing to war condi- tions and prices, but they were made np on the same basis. One lock-coil carrying rope had been changed, and the normal life seemed likely to be two or three years. The ropes were not difficult to change. The cost for hauling ropes had been much too high, and the substitution of ball bearings for ordinary axle bearings was expected to save the rope to some extent. The back balance and driving arrangement were very severe on the rope, and when altered a further saving would be effected. The first, or 50 ft. tower, was buried without being damaged, but the second tower, 75 ft. high, was carried away by reason of the bing slipping to the north. It did not break, but the ropes were slewed 6 ft. out of line. It was cut off about 20 ft. from the top and a new standard erected in its place on the top of the dirt bing on a wooden foundation in proper line. * Colliery Guardian, March 30, 1917, p. 621.