NEIMME: Lamps
STATUTORY RULES AND ORDERS, 1913. No. 89. , MINES.
Coal Mines.
ORDER OF THE. SECRETARY OF STATE, DATED JANUARY 14, 1913,. UNDER SECTION 33 OF THE COAL MINES ACT, 1911 (1 & 2 Geo. 5., c. 50), APPROVING CERTAIN TYPES OF SAFETY LAMPS FOR USE IN MINES TO WHICH THE ACT APPLIES.
In pursuance of Section 33 of the Coal Mines Act, 1911, I hereby approve, until further order, for use in all mines to which the Act applies the types of safety lamp and safety lamp glass described in the Schedule to this Order and subject to the conditions specified in the Schedule.
R. McKenna,
One of His Majesty's Principal Secretaries of State. Whitehall,
14th January, 1913.
SCHEDULE APPROVED LAMPS.
Hailwood Lamp No. 1.
This specification, so far as regards the use of a single gauze, is provisional, and will remain in force only until 1st January, 1914, or for lamps now in use, until 1st January, 1916
The Hailwood Lamp No. l, the general design of which is shown in Plate I., is a single gauze, flame, oil lamp with air feed through vertical holes in the middle ring. It consists of the following essential parts:
(1.) Bonnet or Shield of seamless steel with a separate securely fastened crown or cap.
Height from bottom of middle ring to top of crown
5 inches ± 5/8 inch.
Internal diameter at top
2 1/2 inches 1/8 inch.
Internal diameter at bottom
2 7/8 inches ± 1/8 inch.
Furnished with outlet holes immediately below the crown; provided that the bottom of the holes shall not be less than 3/16 inch above the top of the gauze.
Fitted or not with a deflector (with or without a baffle ring).
(2.) Middle Ring of brass, steel or iron rivetted to bonnet and provided with 5 vertical air inlet holes of total area not greater than 1.1 sq. inches. The inner flange prolonged or not to form a baffle ring.
Pillars of brass, steel or iron, 5, so arranged that a straight line touching the exterior part of consecutive pillars does not touch the glass.
Bush or Bottom Ring of brass, steel or iron.
(3.) Gauze of not less than 28 S.W.G. steel wire, 784 meshes to the square inch, with double-folded lap seams, formed to fit flanges of the inner and outer base rings, and so secured to the same by punch indentations as to make a strong and flame-tight joint.
Internal Dimensions.
Height from the shoulder of the base ring
3 3/16 inches ± 1/8 inch.
Diameter at top
1 5/8 inches ± 1/16 inch.
Diameter at bottom
1 3/4 inches ± 1/16 inch.
Provided that the gauze may be fitted or not with a gauze cap or a Mueseler tube.
(4.) Glass. -Cylindrical.
Height
67 m.m. ± 2 m.m.
External diameter
56 1/2 m. m. ± 1 m. m.
Furnished with top and bottom asbestos washers to ensure flame-tight joints with the gauze and retaining ring.
(5.) Glass Retaining Ring of brass provided with a left-handed screw thread; provided also with ratchet teeth to engage the bolt of the magnetic lock.
(6.) Oil Vessel.-A casting of brass of capacity sufficient to provide the required light for the required time as specified in paragraph 9 below; fitted with a flat 2-inch burner and provided or not with a porcelain body and with an electric spark igniter of the type shown in the drawing so fitted as not to cause the lamp to be dangerous in an explosive atmosphere.
(7.) Locking Device.-A vertical iron bolt and plug kept in position by a spiral spring, and so arranged that the bolt can only be withdrawn by applying the pole of an electro-magnet through the hole in the base of the oil vessel.
(8.) Reflector.-The lamp may be fitted with a reflector.
(9.) Provided
(i.) That the strength of material and attachments. throughout the lamp is not less than in the sample submitted to the mechanical tests on the 24th and 25th October, 1912.
(ii.) That the oil and wick used in the lamp shall be such that the lamp shall be capable of maintaining a light of candle-power not less than 0.30 as determined by a pentane standard all round in a horizontal plane throughout a period of not less than 10 hours.
(iii.) That the lamp has been made at the works of Messrs. Ackroyd and Best, Limited, at Morley, near Leeds.
(iv.) That the glass shall be of an approved type, and that its dimensions shall not be outside the limits laid down in paragraph 4.
(v.) That the lamp shall have marked upon it its name and the name of the maker.
2. The Oldham " Emergency " Electric Lamp.
The Oldham " Emergency " Electric Lamp, the general design of which is shown in Plate II, is of the bull's-eye type. It possesses the following essential features:
(1) A cast aluminium case, with a cover secured by a lead rivet lock.
(2.) An electrical accumulator, so constructed as to prevent escape of the liquid, whatever the position of the lamp, whilst allowing the escape of gas generated by chemical action in the accumulator.
(3.) A flame-tight screwed plug of vulcanite, or other suitable material, enclosing the contact made between the insulated lead and the positive terminal of the cell.
(4.) A switch contained in a flame-tight enclosure, the cover of which, with its washer, is secured by screws. The screw heads are pierced so that a wire may be threaded through, and the ends sealed with lead seals.
(5.) A bulb and reflector contained in a second enclosure, which communicates with the switch enclosure. It is made flame-tight by means of a screwed ring containing the lens, and a washer. The ring is prevented from unscrewing by means of a clip secured by screws, the heads of which are pierced as in the case of the switch cover screws: The lens may be of either of the types shown in the drawing or of other types if not inferior in strength.
Provided
(1.) That the total weight of the lamp is not more than 4 lbs. 8 ozs.
(2.) That the strength of material and attachments throughout the lamp is not less than in the sample submitted to test on the 30th October, 1912.
(3.) That the lamp is capable of maintaining a light of not less than 1.5 c.p. throughout a period of not less than 10 hours.
(4.) That the lamp shall be used only for work of rescue or exploration in the case of an accident or other emergency or by officials.
(5.) That the lamp has been made at the works of Messrs. Oldham and Son, at Denton, near Manchester.
(6.) That the lamp shall have marked upon it its name and the name of the maker.
(b) APPROVED GLASS Glass branded.
Height
67mm ± 21mm
External diameter
56mm ± 1mm
Thickness
4mm ± 1mm Provided that the variation in thickness in any one glass is not more than 1mm.
Provided that the glass shall bear the brand given above. Provided also that it shall have been made by the same manufacturer and is of the same composition and quality as the samples submitted by Messrs. Ackroyd and Best, Limited, of Morley. near Leeds to the official tests on the 24th December, 1912.