76 Modern Fireproof and Watertight Building Materials, 



strength was in no proportion to its price. The material 

 now known on the Continent of Europe under the name of 

 Traegerwellblech is an invention of Messrs. Hein, Lehmann 

 and Co., of Berlin, who succeeded in inventing a machine 

 which corrugates the iron plates in a cold state. Those 

 drawings by which I shall explain the application of this 

 material are partly copies of designs of Mr. A. Lehmann, 

 partly designed by myself. 



As you see from Fig. 1, Traegerwellblech is a corrugated- 

 iron plate, of which the corrugations possess the characteristic 

 of being greater in depth than in width, and whereby each 

 corrugation is formed by perpendicular pieces with semi- 

 circular undulations, so that the whole forms a connected 

 series of semicircular curvatures, connected by the interven- 

 ing iron beams. Traegerwellblech thus represents all the 

 essential features for withstanding: a load, since it offers the 

 greatest moment of resistance with a minimum of dead- 

 weight. Subsequent to the conflagration of the Kaiserhof 

 Hotel, in Berlin, in 1875, Traegerwellblech was largely used 

 in the nrocess of restoration for the landings, staircases, 

 corridors, and partition walls, especially in lieu of brick arch- 

 ing between iron girders, which, on account of unequalised 

 expansion, had ill withstood the effects of fire, and 

 collapsed. 



The Zeitschrift fur Bauwesen, the leading German journal 

 for architecture and civil engineering, issued by the Minister 

 of Public Works, expresses itself as follows (page 169, year 

 1877) : — " The opportunity thus afforded for exhibiting 

 Traegerwellblech in the dual character as a fireproof 

 medium and as a bearing construction for the massive walls, 

 seems to point to the probability of the usefulness of this 

 material to purposes in the architectural constructions, and 

 its application can be highly recommended," and further 

 on calls particular attention to the state of brickwork 

 arching between iron girders. " The flat brickwork arching 

 between iron girders withstood the fire badly ; the un- 

 yielding bonding of the bricks became detached from the 

 expanding iron beams, the collapsing material, meeting with 

 no resistance, fell in, and the vaulted spaces were thus 

 deprived of all protection from fire." 



Traegerwellblech plates are made in lengths up to 15 

 feet, the breadth varying from 1 foot 6 inches to 2 feet 

 2 inches; the thickness of the iron is between one and five 

 millimeters. (19—10 B.W.G.) 



