Annual report of the City Engineer (1908) (14595273138)

Identifier: annualreportofci1908bost (find matches)
Title: Annual report of the City Engineer
Year: 1867 (1860s)
Authors: Boston (Mass.). Engineering Dept
Subjects: Public works
Publisher: Boston, Mass. : Office of City Engineer
Contributing Library: Boston Public Library
Digitizing Sponsor: Kahle/Austin Foundation and Omidyar Network



Text Appearing Before Image:
ompany decided to place a concreteprotection upon the floor beams of the street railway struc-ture, and at the request of that company the design forthe protection was made by the Engineering Departmentof the city, the details being shown in Fig. 7. In ordernot to add too much dead weight to these beams it wasdecided to make the concrete only 2 inches thick on eachside of the web and to incase each stiffener angle. Thewhole of the top flange and the top side of the bottom flangewas protected. No protection was provided for the under-side of the bottom flange, partly on account of limited head-room, but more especially because it was thought that theprotection could not be held in place owing to the blastfrom locomotive stacks, the tops of which come withina few inches of the beams, and also because of the likelihoodof the concrete or mortar cracking at the edges of the flangeand exposing the reinforcing metal to corrosion. Slabsor pieces of mortar falhng upon passing trains would be a
Text Appearing After Image:
BoYLsroN Str££T Bridge dC/T THE. BostonAiiOAlbany /iAJi/tavx CoM:/fer£ Protection or TLOOf^ Qcams. Scales; one-half and oncfuarter s»zc O^CNtHG IN Street fiMLimr fioom Beam HECTiNS C/TY ^LOOft BeAMS \ _--__ . _ /^ - ,. (Qusffer Sizel -BOYLSTON STREET BRIDGE DRAWING SHOWING CONCRETE PROTECTION OF FLOOR BEAMS, Engineering Department. 53 source of danger to passengers within the cars, as has beenshown by experiences elsewhere. To hold the concrete pro-tection in place at the top flanges, rivets were cut from theouter gauge lines at intervals of about 2 feet and angles werebolted to the underside of the flange, a clearance of 1 inchbeing provided between the angles and the edges of theflange plates, and an equal or greater clearance being allowedat the underside of the flange. The concrete at each side of theweb was held by Clinton wire cloth, 3-inch by 8-inch mesh,eight and ten gauge wires, held by ;-inch bolts through theweb, holes for the bolts being drilled in the field and the bo