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

Marks: 4M

Year: May 2015, Dec 2015

Semaphore signal:

1. It is also termed as semaphore type signals. In such type, there is a vertical post on which a movable arm provided at the top. The length of arm ranges from 1.2m to 1.7m. Arm is wide from 23cm to 25cm at inner edge whereas 25cm to 35cm wide at outer edge.
2. In India, these types of signals are located on the left hand side of the track. It is one of the earliest forms of fixed railways signal. These signals display their different indications to train drivers by changing the angle of inclination of a pivoted arm by pulling the levers from the signal cabin.

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