Rudimentary treatise on the construction of cranes, and machinery for raising heavy bodies, for the erection of buildings, and for hoisting goods / By Joseph Glynn.

  • Joseph Glynn
Date:
1849
Catalogue details

Licence: Public Domain Mark

Credit: Rudimentary treatise on the construction of cranes, and machinery for raising heavy bodies, for the erection of buildings, and for hoisting goods / By Joseph Glynn. Source: Wellcome Collection.

    117/170 (page 71)
    TRANSVERSE STRENGTH oF Bars, ONE INcH SQUARE, LAID ON Supports 4} FEET ASUNDER, AND BROKEN BY A WEIGHT IN THE MIDDLE. eae Seba LE ie eee een Vad Ce 2 ee Oe ee Ratio of Description of Iron. Cold Blast. | Hot Blast. ae mae Tron being 1000. Biffery, No.1. . . .| 468 (3) 436 (3) | 1000: 942 @tiron, No.2, . . . | 476, (3) 463 (3) i RROTS Coed Talon, No, 2.. . | 408°7(3) | 409-2 (2) » : 1001 Da .do. Ned... 538 (2) 496 (2) Pie 4 Catron, No: Sifax. _. 444 (3) 520 (3) » 4470 Deven, No.3. . . 448 (2) 537 (2) » +: 1190 Muirkirk, No.1... . 444 (2) 418 (2) 3 te VED Elsicar cold and Milton hot blast, No. 1, .. 430 (2) 302 (2) » + 819 Wrought iron is seldom used on the thrust in construct- ing cranes; but its strength, compared with that of cast iron, applied as a pillar, is nearly 75 per cent. greater. It has, however, been found, by experiments carefully made, that it is permanently compressed with about 1] tons on the square inch of transverse section ; with loads below that weight, the bar or pillar regained its original length. It is almost invariably, in large cranes, upon the stretch, and mostly in the manner shown in the 5-ton crane. (See the Plate.) Its tensile streneth is directly proportionate to the area of its transverse section. A series of experiments were tried by the late Mr. John Kingston, in the dockyard at Woolwich, which are given in all their details in the Transactions of the Society of Arts, Volume 51, 1837, Inches. A bar 1} inch with 5 tons stretched ‘O11 in 100 2) a3 10 d9 9) 054 bb) 79 PP) 15 ) 9 | 10 PP) » spi! DBS} ‘5 1:35 broke.