Mumbai University > Civil Engineering > Sem 5 > Transportation Engineering 1

Marks: 5M

Year: May 2016

Working of semaphore signals:-

• The side arm facing the driver is painted red with a white vertical band and opposite side of arm is painted white with a black vertical band. Centre of the semaphore arm is at 7.5 m above the ground level normal position of the arm of a signal is horizontal and it can be lowered at an angle of 45º to 60º with respect to horizontal.
• Horizontal position of arm indicate ‘stop’ or danger and when arm is lowered at an angle vary from 45º to 60º, it indicate “proceed”.
• At night hours, red light indicates ‘stop’ or danger and green light indicates ‘proceed’.

Components of semaphore signals:

It consists of following parts:

• Wooden metal arm or blade i.e. semaphore arm which pivots at different angles.
• Spectacle holding colored lenses which move in front of lamp in order to provide indications at night.
• Lever
• Crank rod
• Weight
• Pulley
• Lamp
• Spindle
• Spectangles
• Wire over the pulley from control cabin