To view this newsletter as a web page, go to:

- Best view with 1024 x 768 resolution -

Institution of Railway Signal Engineers
(Hong Kong Section)

IRSE(HK) Home | Newsletters - Past Issues | Contact Us

 IRSE(HK) Newsletter > News
 Issue 06 @ March 2010 

Landslide Detectors

Y F Sung
Secretary, IRSE(HK)

Landslide detectors are installed when the track itself is in danger of sliding away by earth slide or snow slide. Detection is made by weak cables strung in zigzag formation within the risk zone from fixed points or trip wires placed along the track.

Figure 1 Trip Wire for Landslide Detection

The trip wire at the section pulls a pair of break contacts of a relay at each end and picks up a proving relay. Breakage of wire causes protecting signals to be placed to danger or triggers other signals or ATP to make the approaching train to stop. The detector may also send an alarm to the control center or nearest station or signal box. 

Similarly, where the flight path at the perimeter of an airfield passes low over an adjacent railway, trip wires are provided. Should an aircraft break these wires protecting signals are held at red in case debris has landed on the railway or damaged has been caused to railway equipment. In addition, direct telephone communication is available between the railway control center and airfield control tower in the event of an emergency.

Another solution for solving this type of problem is the installation of CCTV, which gives the traffic operator a view of the area, enabling him to stop the traffic if a dangerous situation occurs.

(Reference to Railtrack)

* * * End * * *

Comments and suggestions are welcome. Please send an e-mail to Editorial Team.

As a member of IRSE(HK), you will receive a bi-monthly email newsletter.
IRSE(HK) respects your privacy. If you no longer wish to receive this e-newsletter,
please send an e-mail to IRSE(HK) Administration (E-mail: to unsubscribe.

Copyright © 2009 Institution of Railway Signal Engineers (Hong Kong Section)
10/F MTR Headquarters Building, Telford Plaza, Kowloon Bay, Kowloon, Hong Kong.
All rights reserved.