. Electric railway journal . rm and con- March i, 1913.] ELECTRIC RAILWAY JOURNAL 365 necting with the lock shaft by a worm gearing. The basculeleaves may be raised separately or together, and while both40-hp motors are ordinarily operated in raising the drawbut one is necessary for the work. A special feature of the draw, which was described in theElectric Railway Journal of Sept. 21, 1912, page 461,is a motor-operated bumper located in the center of theapproach to the opening on each side and about 30 ft. fromthe bascule. Each bumper consists of a riveted steel framepivoted to two castings b
. Electric railway journal . rm and con- March i, 1913.] ELECTRIC RAILWAY JOURNAL 365 necting with the lock shaft by a worm gearing. The basculeleaves may be raised separately or together, and while both40-hp motors are ordinarily operated in raising the drawbut one is necessary for the work. A special feature of the draw, which was described in theElectric Railway Journal of Sept. 21, 1912, page 461,is a motor-operated bumper located in the center of theapproach to the opening on each side and about 30 ft. fromthe bascule. Each bumper consists of a riveted steel framepivoted to two castings bolted to the ties. Normally thetop of the frame is a little below the top of the rail, butbefore the draw is raised a 3-hp motor raises the bumperin the track, completely blocking the passage of the car,the frame forming an angle of about 20 deg. against ten seconds are required to raise or lower thebumpers. The control of the draw movements and of the locks,bumpers and signals governing the approach of cars is. Boston Improvements—Typical Block Signal, East Cam-bridge Extension centered in an operating room in the drawtenders tower,where a three-panel switchboard is mounted parallel to thetracks, so that a clear view can be had in each lock, signals and main motors are all interlocked toprevent any possible accident. In the cycle of opening andclosing the draw all approach signals are set at dangerby the operation of hand levers in an interlocking machinein the tower; the bumpers are then raised, the bridge leavesunlocked and the bascule opened. In closing, the reversetakes place. The interlocking is greatly facilitated by theuse of contactors in the more important circuits. Thebumper motors start on line voltage without the use ofrheostats. Magnetic brakes are provided on the main drawmotors, and in addition an emergency braking outfit is in-stalled, with foot lever control in the operating room. In-dicating lamps are provided to show the draw op
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