124 THE COLLIERY GUARDIAN. January 17, 1913. as against 2,500 ft. per minute, which the writer believes is the highest in use elsewhere, at all events with A.C. winders. With the present arrangement, in the event of failure of supply, the emergency device trips the main circuit breaker, and applies the mechanical brakes automatically, the eddy current brake being available for hand application by the driver; in the opinion of the writer this arrangement would be much improved were the action of the no-volt release coil confined to applying the eddy current brake in the “ full-on ” position; by this arrangement the first notice that the driver would have of failure of supply would be the very rapid slowing down of the hoist, his duty then being to return his controller*to the “ off ” position and to stand by his mechanical brakes to stop the hoist at the end of the wind. Should the supply come on again before the end of the trip, as might easily happen had the failure been due to the accidental tripping of a circuit breaker, the driver would be able to apply counter-current in addition, if necessary. The existing overwinding gear would, of course, have to apply the mechanical brakes and cut off the supply in case of overwind; but this could be easily modified to make it operate inde- pendently of the no-volt release. This form of brake lends itself admirably for use with overspeed devices or automatic application when the skip approaches the bank; such arrangements usually operate in connection with the overwinding gear, resulting in an emergency application of the mechanical brakes, which is to be avoided as far as possible. The extra cost of this brake is serious, being approximately £2,000 for the equipment of a 5-ton hoist with a rope speed of 3,500 ft. per minute, which includes the motor generator and battery for the exciting system; but it will be found that with A.C. hoists the investment of this amount of capital is a profitable one altogether apart from any considerations of additional safety to life and property, or convenience of high speed working. Estimates show a saving of about £400 per annum, consequent upon a capital cost of £2,000 for an eddy current brake, and this, in the opinion of the writer, is a decidedly conservative one. With regard to the application of the eddy current brake to steam and Ward-Leonard hoists, apart from the consideration of the effect it might have upon the authorised man winding speeds, the only advantages it would appear to offer would be that of a braking method for unclutched drums, the ideal equipment including two brakes bolted to the flanges of the drums ; with such an equipment runaways would become practically impossible, With steam winders the exciting current for the brakes could be conveniently obtained from a small direct-connected steam driver generator situated in the engine-room itself. The extra cost of such an equipment would, however, almost put it out of the question as a safeguard against what is, after all, an extremely rare occurrence. For higher speeds than 3,500 ft. per minute the advantages of eddy current braking would, of course, be still further accentuated, and this method of braking would appear to make much higher rope speeds practicable and safe. In this contribution the writer has purposely omitted the consideration of electric hoists with series parallel control, as the use of this system is limited to winders of comparatively small capacity, although there are some very successful equipments of this type in operation.* * For the photographs accompanying this paper we are indebted to the British Westinghouse Company, to whom is due the introduction of the eddy current brake. Grimsby Coal Exports.—During the week ended Friday the exports of coal to foreign ports from Grimsby were shown in the official returns to be as follows :—Antwerp, 401 tons ; Brake, 1,446 ; Copenhagen, 1,602 ; Dieppe, 691 ; Esbjerg, 691 ; Fredrikshald, 1,163 ; Gothenburg, 3,194 ; Hamburg, 316 ; Helsingborg, 1,503 ; Kiel, 2,627 ; Malmo, 2,006; Oxelosund, 2,904; Banders, 603 ; Reval, 2,318 ; Riga, 2,304; Ronneby, l,6S0; Rotterdam, 5,310; Savona, 2,390; Stavanger, 555; Trelleborg, 2,001 ; and Wismar Town, 3,126 ; total, 38,831 tons. There was only one coastal shipment of 107 tons to London. Auckland Park Colliery Explosion.—In answer to a further question by Sir Henry Havelock-Allan in regard to this explosion, which occurred on October 29, Mr. McKenna states that he has received a further report from the district inspector stating that the examination of the cable under the large fall shows conclusively that the cable was not the originating cause of the explosion. The origin of the explosion remains a mystery, and the Home Secretary is afraid there is not much likelihood of any further light being thrown on the subject. He has, however, asked the Chief Inspector to visit the mine and to review all the facts in consultation with the district inspector and other persons who have been investigating the matter. NEW DRAFT GENERAL REGULATIONS. In pursuance of section 86 of the Coal Mines Act, 1911, the Home Secretary has now proposed a code of General Regulations to apply to all mines to which the Act applies, and coming into force on April 1,1913. In the course of an explanatory circular, Si,r Edward Troup, the Under-Secretary, says:— I am directed by the Secretary of State to transmit, herewith, a copy of a draft of General Regulations for mines under the Coal Mines Act, 1911, which he proposes to make under that Act. The Regulations are divided into seven Parts. Part I. contains the regulations under Section 86 providing generally for the prevention of accidents and the safety, health, convenience and proper discipline of the persons employed, and will take the place of the general codes of Special Rules at present in force in the different districts. Part II. consists mainly of Regulations on certain specific matters in respect of which the Act requires or authorises regulations to be made. The candle rules in this Part are based on the rules which were drawn up for mines in Staffordshire after the Hamstead disaster. Part III. embodies the existing Special Rules on the subject of the Installation and Use of Electricity with such drafting alterations only as are required by their transformation into General Regulations under the Act of 1911. Part IV. contains provisions as to rescue and ambulance. The rescue provisions embody the rescue Order already in force, without alteration, except that the temporary provision in Clause 5(a) of the Order has been omitted, and a minor alteration has been made in Clause 3(b), (viz., the addition of the words “ or other Society or body approved by the Secretary of State ”) for the sake of conformity with the Rules made under Section 9 of the Act as to the qualifica- tions of candidates for managers' certificates, and with the proposed Regulations as to ambulance. Part V. embodies the existing Special Rules as to surface lines and sidings with the alterations required by the transformation of the Rules into Regulations under the new Act; and Part VI. contains Regulations for sinking pits based on the Special Rules now in force in different districts. Part VII. revokes all existing Special Rules. In accordance with the requirements of the Act the Regulations are issued in the first instance as a draft. If within fifty days from this date, i.e., before 1st March next, a