1134 THE COLLIERY GUARDIAN. November 29, 1918. Leeds and Chesterfield being suggested. The matter was left in the hands of the committee. Delegates to the General Council. The Chairman reported that the following had been elected delegates to the _ general council: Messrs. J. A. Wilson, G. H. Lant, J. T. Price, C. Chrisp, J. W. Lee, and B. W. Haigh. NEW COKE OVENS AT FENCE HOUSES. The presidential address delivered by Dr. G. P. Lishman, of the Lambton Coke Works, Fence Houses, Durham County, to the members of the northern section of the Coke Oven Managers’ Association, at their meeting in Durham City on Saturday last, took the simple form of a description of a new installation in * connection with his firm’s activities at Fence Houses. Dr. Lishman stated that his firm had recently built 35 Simplex regenerative ovens at Lambton. As that was not a very well-known oven and the section was down for a visit there next year, he thought it might interest the members if he gave some account of the construc- tion of the ovens. They decided on regenerative ovens, because they did not want another boiler plant, and the gas from the regenerators could be taken to a power station a mile and a-quarter away. Many considerations entered into the arrangement of the by-product plant. They had an indirect recovery plant for 35 ovens, including a rotary scrubber, and r-’om for only two 100,01)0 ft. per hour exhausters in the exhaust house. It was therefore undesirable to have two separate streams of gas, as in that case there could not be a spare exhauster for either battery. It was finally decid'd to have one stream of gas on the pressure side—the suctions from the two batteries uniting at the exhauster and being regulatable by valves. The gas then went through a Pelouze to the saturator, then, after cooling, to the benzol scrubber, which consisted of the old rotary ammonia scrubber, rebrushed, plus the former tower benzol scrubbers. In that way, all the old w 3 3 Elevation. ' Section. w plant was used in except the saturator and a serpentine tar extractor, which was nearly worn out in any case. The new coolers were both serpentine in cast iron. The ovens were 33 ft. long, by 7 ft. 4| in. to arch key by 20J in. They would have had them much larger but length and height were determined by the old battery, and they had no wish to alter the width. The oven walls were parallel in both batteries. The intro- duction of parallel walls was due to the Solvay people and was, in many obvious ways, a great advantage. It was said that there were some expanding or salt-con- taining coals for which parallel walls were unsuitable, but he did not believe it. Tapered ovens were a relic of « the days when, owing to uneven heating, ovens could not be pushed and some brilliant genius thought that, by giving 2 in. taper in 400 in., he was doing something to win the war among coke-oven constructors.' There were lots of things like that lurking about coke-ovens, some of them in very unexpected places. To return to the ovens, there were 28 vertical flues, 14 on the ram side being connected with 14 on the hearth side only through a longitudinally split sole flue. While the even-numbered sole flues were divided longitudinally, the odd numbers were divided transversely, and these latter alone communicated with both regenerators. There was no means of inspecting the vertical flues excepting over the top of them, where, from each side, one could see half-way along. There were sight-holes for the sole flues, but these were not used in the ordinary way. The regulator could see if his draught was right by looking along the top of the regenerator. The burners were all at the top, 14 of them in each wall. These were never put out but, when the draught was reversed at each half-hour, the flame changed over and went down the next flue, up which air had been coming. All the regulator had to do was to reverse his dampers—one hand-winch worked all four—and to clean any burners which might have choked up. There was no gas regulating as long as the ovens were being pushed as soon as ready. The distribution of air, gas and products of combustion was obtained by the dimen- sioning of the flues. The regenerators were built of bricks 10 in. X 4| in. X 3 in., so that, when built on edge with a 2 in. space, the 10 in. cross bricks butted against each other. The whole space was filled 60 per cent, by brick and 40 per cent, by air. The regenerator space per oven was 9 cu. m., 4J on each side. The temperature of the waste gas going to the chimney was generally round about 270 degs. Cent. The top third of the regenerator was filled with first quality bricks, the lower two-thirds with second quality. The point to nota was that, on reversal, the burners were first applied not with air but with products of combustion from the regenerator. That lasted for three or four minutes, and during that time the gas did not burn at all, and was simply wasted. When the scheme for sending the surplus gas to a power station was ready, it would include a method of saving that gas, by cutting it off from the ovens entirely and letting it into a gas-holder, from which it would be evacuated during the next 25 minutes, /.e., the ordinary 40 per cent, of surplus gas they sent to the station would be augmented every half-hour by some 2,000 or 2,500 cu. ft. which would otherwise have gone through the burners. As that amounted to about 90,000 ft. per day, it was worth having. THE “STRONG” SIGNALLING APPARATUS. A special feature of the “ Strong ” signalling appa- ratus is that it registers “ Men ” and “ Right away ” signals on one dial only, and also has illuminated figures which are especially useful in the dark. The apparatus is mechanically and electrically constructed, and so designed as to provide a non-cumulative, visible, illuminated and audible indication of the signal from the pit bottom to the engine-house, whilst at the same time it cannot return to “ Zero ” until after the engine has started. It is also impossible for the bell to ring a signal without the number of the signal being indicated by the finger on the dial, or vice versa. In the illustrations, A is a signal bell, B a striker rod operated mechanically or electrically in a usual manner, C a stationary dial, and c a pointer. A pawl b on the striker rod B operates the bell hammer a, and a pawl b1 rotates a ratchet wheel D on the spindle d (carrying the pointer c) so as to move the pointer in front of the stationary dial. The dial box E is provided with transparent numerals to indicate the strokes of the signal, the numerals being successively illuminated by electric light bulbs e, which are connected with separate electric circuits and are brought into the main circuit and illuminated successively as the strokes of the signal are given, a switch F rotating with the pointer, and successively completing the lamp circuits by way of the contact points f and fingers fl, each lamp being cut out as the next is switched on. An auxiliary rotary switch K connectsan independent lighting circuit with the lamp of the signal No. 3—“ Men ”—to keep this signal illuminated when the signal “ Right away ”—or No. 1—is given to raise the cage, so that the engineman is constantly reminded that he is winding men. As one dial only is used, the engineman has only one dial to watch, and therefore cannot make a mistake. Also, as only one pull-wire is required, the man at the pit bottom cannot pull the wrong wire and thereby show a wrong signal in the engine house, as might occur with indicators having two dials and two pull- wires. The apparatus is so constructed that, should the electric current be cut off through any cause, the mechanical part is not affected in any way, and will continue to correctly record, both visibly and audibly, any signals given. The pit bank indicator is an electric indicator only— the lamps in this being controlled from the signal dial in the engine house. This indicator should be especially useful to the banksman, as it always shows him what signal has been given from the pit bottom to the engine house. The indicator, which has been patented, is made by the Clay Cross Company Limited, near Chesterfield. Iron and Steel Wire and Wire Ropes.—The Minister of Munitions gives notice that no permit is now required from the Ministry of Munitions or any other Department for the manufacture or sale of iron and steel wire or wire ropes for the home trade. The Government will, where necessity arises, continue to issue priority permits for work of special national importance, and firms may still issue priority certificates where the Order as to priority of March 8, 1917, allows them to do so. ELECTRIC POWER SUPPLY. With reference to the interim report of the Coal Con- servation Sub-Comm it tee of the Reconstruction Com- mittee and the report of the Electric Power Supply Committee, a statement has been issued on behalf of local authorities in the north-east coast area who are electricity undertakers—viz., the borough of Berwick-upon-Tweed sanitary authority; the county borough of Middles- brough ; the city and county of Newcastle-upon-Tyne; the county borough of South Shields; the borough of Stockton-on-Tees; the county borough of Tynemouth; the county borough of West Hartlepool. The report appears below. The municipalities concede that the unification of the production and distribution of electrical energy for areas sufficiently large but carefully defined is desirable, provided that the best use is made of existing systems of generation and distribution; that the generation and distribution of electrical energy is under local public control, and that proper and reasonable safeguards are adopted in the interests of existing undertakers and consumers, and, in particular, that those municipal undertakings which, by their situation, equipment and other circumstances, can, in the opinion of the Electricity Commissioners, be economically worked without inter- fering with the efficiency of any general scheme, should continue to be owned and operated by their present owners. Limitations of areas of supply have, in tho north-east coast area, operated to restrict expansion and to limit economy of production in regard to municipal electrical undertakings to an extent markedly greater than has been the case with regard to private supply companies, and, in so far as the reports affirm the desirability of widely extended areas of supply, the municipalities are, subject to the qualifications stated above, in agreement with the recommendations of the reports. With respect, however, to the Coal Conservation Sub- Committee’s report, the recommendations of which, it is to be observed, extend considerably beyond the scope of the matters referred to the Sub-Committee by the Reconstruction Committee, the municipalities cannot ignore the fact that a report purporting to deal with problems of national economy in coal consumption has been utilised as a vehicle of attack upon the policy of municipal control of electricity undertakings, and has been made the means of promulgating proposals which, if carried into effect, may be expected in the north-east coast area—whatever be the course adopted elsewhere— to consolidate the position of the Newcastle-upon-Tyne Electric Supply Company and its allied and subsidiary companies, and to involve the subordination of muni- cipal electrical undertakings to the dominance and control of the north-east coast group of power companies. Question of Coal Saving*. The report of the Coal Conservation Sub-Committee is accepted by, and has clearly influenced, the Electric Power Supply Committee in arriving at their conclu- sions. The report cannot, however, be regarded as presenting any elements of finality, nor as offering other than the expression of the individual opinions of its framers. Its conclusions are sought to be supported mainly by an estimated coal saving of 55 million tons per annum, and by a comparison between the average charge for electricity in the north-east coast area and the charges of a number of municipalities in the southern parts of Lancashire. The municipalities challenge the statement that a coal saving such as is estimated by the Coal Con- servation Sub-Committee will be effected, even supposing the proposals of the reports be put into operation forthwith, and they are prepared, on being afforded an opportunity of placing their views before an impartial authority, to give in detail the grounds upon which they dispute the accuracy of this estimate. The estimate, moreover, rests upon figures which are stated in the Coal Conservation Sub-Committee’s report and its appendices in such a manner as to afford no means of investigation and verification. The adverse comparison sought to be drawn by the Coal Conservation Sub-Committee between the alleged “average charge of less than Jd. per unit” of the north-east coast supply companies and the charges of the Lancashire municipalities, is misleading and mischievous. No details are vouchsafed in the Sub- Committee’s report showing how this alleged average charge is arrived at, and the municipalities deny that it is in any sense a true and accurate representation of the facts. On the contrary, the municipalities assert that where all material factors are taken into consideration, the charges of the north-east coast supply companies will be found to approximate very closely to those of comparable municipal undertakings. Even should the allegation of an average charge of less than Jd. per unit be justified on the ascertained facts, the comparison is none the less misleading and fallacious, because (apart from other considerations) the statement in Table V. of the Coal Conservation Sub- Committee’s Report purporting to give the average prices charged for power by the Lancashire munici- palities, gives prices which include the cost of distribu- tion and other incidental expenses, and relate very largely to low-tension units supplied to consumers on their own premises, whereas a large proportion of the units supplied by the north-east coast supply com- panies, the prices charged for which are apparently taken into account in arriving at the average charge of less than Jd. per unit, are high-tension units supplied in bulk to the distributors and users of electrical energy who, generally speaking, have to add the cost of trans- formation, and in some cases that of distribution, together with their profit, in the price actually charged to the ultimate consumer. Centralisation. The municipalities regard it as a matter of regret that the comparison thus drawn by the Coal Conserva- tion Sub-Committee should have been permitted to enjoy currency as the considered opinion of a committee appointed to arrive at authoritative conclusions upon matters of grave public import.