FIRE TESTS WITH DOORS.
HOW far deal doors and pine doors resist the action of fire Was recently tested in London by the British Fire-Prevention committee. The tests were made with a two and five-eightbs-inch door of Archangel deal and one of Quebec pine, of the same thickness. These were subjected to a fierce fire of one hour’s duration—gradually increasing to a temperature of 2,000 degrees Fahr. The fire was applied from one side, and the doors, whose openings were approximately three feet, three inches by six feet, nine inches, opened in wards on to the fire side. The doors, which were seven feet high by three feet, seven inches wide, were constructed of three thicknesses of seven-eighths of an inch board— the middle thickness being horizontal, and the outer ones, vertical. All were tongued and grooved on the solid, and nailed with three-inch clasp nails clinched on the outside. Each had wrought iron strap hinges—one near the top and one near the bottom, two feet, six inches long, two and one-quarter inches wide, and three-eighths of an inch thick, bolted through the door with four three-eighths of an inch iron bolts. The hinges turned on wrought iron pins, the ends of which were built into the walls of the testing hut. On each door were fixed two wrought iron latches—one near the top and one near the bottom—with wrought iron catches built into the walls. The doors were hung in brick rebates, and before they were putinto position these rebates were screeded with plaster mixed with lime mortar. The doors fitted closely against the screeds, and the joint between the door and the brickwork was pointed on the outside immediately before the test.
The testing hut was built of stock bricks with lime mortar, and measured ten feet by ten feet internally. Its ceiling was nine feet, six inches above the pavement, and was formed of solid wood beams grouted with fireclay. The chamber in which was the fire measured ten feet by seven feet, ten inches. As in previous tests, the fuel used was gas made at the station, and admitted through two mixing chambers of firebrick —the supply being regulated by valves and dampers. Two Roberts-Austen pyrometers were used for recording temperatures, to take four observation records from four points, two of which were outside the doors, and the others on the fire side of the door. A continuous self-recording record was also taken from another thermo-point attached (as were the others) by wires leading to the pyrometers. There and the ceiling being nine feet, six inches. The two openings were arched over with brick arches in two half-brick rings, and one course of bricks was put in below the arch resting on a T iron built intothe wall at both ends. The wall was built with gauged stuff.
The test of each door began at 2:30 p. m., when the gas was turned on and lighted. Two minutes afterwards smoke was seen issuing outside through the joint between the top of each door and wall, and this continued without intermission throughout the test. At 2:50smoke al o came out down the joint between the pine door and the wall on the west side about eighteen inches, and on each side of the deal door about two feet. Signs of heat were also showwhile two of the heads of the corresponding bolts in the deal door were a full blue color. At 3:7 a creaking sound was heard, and at 3:9 flame appeared entermittingly over the top of the deal door. At 3:10 all the bolt heads in each door were black hot and scorching the surrounding wood, and burned a pie_____e of paper when applied. The outer face of each door was dry, and the joints generally were one thirtysecond part of an inch open. In the case of the pine door at 8:12 all the clinched ends of the nails in the doors were scorching the boards on the outside face. In the case of the deal door flame appeared intermittingly at 3:12 at the west top corner about twelve inches at the side. The wood adjoining the west bolt of the bottom hinge showed fire above and below it. All the clinched ends of the nails used in the door were scorching the boards on the outside face. At 3:13 smoke came from the scorched wood round the bolts to the lower hinge of each door. At 3:18 the fire round the west bolt in the lower hinge of the deal door had burned the hole upwards and downwards, and this hole was extending. At 3:20 there was no sign of flame round the pine door; but the wood round the bolts and nails was much scorched. At 3:22 there was no sign of flame, but increasing scorching of the wood on the outer face of the door. At the same moment the flame was increasing along the top of thedeal door and down the joint on the west side. Three minutes afterwards flame came through the joint all along the top and down the west side nearly half-way, and also through the upper portion of the deal door west of the centre; also at the bottom by the west bolt, and at four other small points. At 3:30 flame came through the joint at the top, down the west side, bursting also through the upper part of the pine door in several places There was no sign of burning round the bolts of the lower hinge. At 8:34 the flames coming through the holes burned in several parts of each door had greatly increased, and a number of smaller holes had been burned through the whole thickness. At 3:35 the gas was turned off, and at3:37 the wafer was applied to the outer face of each door for one minute.
According to observations on the inside, at 2:36 the face of each door was blazing freely all over, except a very small portion at the bottom of the pine door on the west side, and of the deal door on the east side. At 3:2 small pieces of the inner thickness of the pine door were falling off at the bottom, and pieces of the deal door in several places At 3:3 the bolts and latches of each door were bright redhot.
To summarize the effect: In the case of the deal door—In thirty-nine minutes flame appeared over the top intermittingly; in forty-two minutes flame also appeared down the west side about twelve inches; in fifty-five minutes flame came continuously through the upper portion of the door; in sixty-five minutes the upper portion of the door was considerably burned, and flame was seen through several small holes burned in the lower portion of the door.
In the case of the pine door—In fifty two minutes no flame had come through the door or from the joints round the same, although much smoke had come from the joints, and the wood round all the bolts and nails was much scorched; in sixty minutes flame came over the top of the door and also through its upper part in several places; in seventy minutes, after water had been applied, the two inner thicknesses of the door were found practically burned away, and the outer thickness (which was for the most part in position) much damaged.
The illustrations accompanying this notice show the condition of the inside of the doors after the test; the condition of the outside of the doors after sixtythree minutes, and their condition after the application of water one hour and nine minutes after the gas had been lit, and four minutes after it had been put out.