. Electric railway journal . ings, battery boxes, etc. Inmaking this conduit, the fiber is molded into shape under hightemperature and immense pressure, and is entirely withoutgrain or laminations. This process gives each length of con-duit a solid, ^8-in. one-piece homogeneous wall, with a tensilestrength that is remarkable when compared with the lightweight of the conduit. However, the most interesting featureof this conduit lies in the bell joints illustrated. One end ofeach section is belled out with an opening as large as the out-side diameter of the opposite end of the next section. Anyt
. Electric railway journal . ings, battery boxes, etc. Inmaking this conduit, the fiber is molded into shape under hightemperature and immense pressure, and is entirely withoutgrain or laminations. This process gives each length of con-duit a solid, ^8-in. one-piece homogeneous wall, with a tensilestrength that is remarkable when compared with the lightweight of the conduit. However, the most interesting featureof this conduit lies in the bell joints illustrated. One end ofeach section is belled out with an opening as large as the out-side diameter of the opposite end of the next section. Anytwo sections fit together without any reduction in the wallthickness of either section at the joint. In laminated fiber conduit, half the wall thickness at the endsof each length must be cut away in order that one length mayfit or screw into the other. This, of course, reduces thestrength of the joint by half. The manufacturer has also arranged to make this new con-duit with straight line joints, which are machine-moulded and. Three Types of Fiber Conduit Bell Joints are perfectly smooth inside. Each length of the conduit isalso smooth throughout its bore. This greatly facilitates theinsertion of cables and saves them from abrasion. It is as-serted that since there are no seams or roughness at the jointsand as the air-tight joints prevent particles of concrete fromseeping through, a No. 6 wire can be pushed through eachduct from manhole to manhole, doing away with the ropesand rods necessary with ordinary conduits. The smooth, tightjoints and the smooth bore of this conduit should add greatlyto the life of cable. Tests made of this conduit with ty&-m. thickness of wall showthat it has an average puncture voltage of 40,800 volts dry and33,000 volts after 40 hours immersion in water. Danger ofelectrolysis should therefore be practically eliminated by theuse of this conduit. This conduit weighs only about one-sixthas much as stone. This makes it easier to handle and cutsdown the fr
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyorkmcgrawhillp
