The Joondalup water tower will play a small but vital role in Perth's new northern suburbs rapid transit system.
The tower soon will be the home for two microwave dishes and mobile radio antenna masts being installed as part of the communications links for the railway.
Transport Minister Pam Beggs today said antennas and dishes would complete a microwave radio communications link between Westrail's East Perth headquarters and the new Currambine Station to be built near Burns Beach Road.
At Currambine, the microwave link would connect into a fibre optic cable looped into all stations along the line.
Together, these systems would form the backbone of a network used to control the main railway systems.
Mrs Beggs said these included signals, the 25,000 volt electrical supply as well as catering for station services such as passenger information displays, ticket vending machines and telephones.
The microwave-fibre optic system also would be used to extend Westrail's mobile radio network so train controllers in the Westrail Centre could co-ordinate the movement and activities of trains, maintenance services, passenger attendants and emergency services.
"Uninterrupted radio communications with the trains is essential to ensure passenger safety," Mrs Beggs said.
"But in the Joondalup area, there are a number of bridges, tunnels and deep cuttings along the railway line that would interfere with radio transmissions.
"This problem will be overcome by taking advantage of the position of the Water Authority's tower at Joondalup as a base for the antenna masts."
A separate building would be constructed next to the tower to hold other communications equipment.
Telecom also would use the building for its mobile telephone network.