JEDDAH — Construction companies that use tower cranes must get ground soil tested from a specialized laboratory before operating the heavy machinery, the Civil Defense Department said in a statement. "The companies should produce a certificate for soil test from an authorized agency to make sure the capability to hold heavy load," the statement said. The test should cover the effect of the crane's movement on the soil as well as the aerodynamic effect at times of strong winds, the CDD said. The new condition comes two months after a huge crane collapsed on the Grand Mosque in Makkah on Sept. 11, killing 111 people and injuring 238 others, mostly pilgrims. The CDD urged contractors to take a number of protective measures before operating tower cranes to avoid similar deadly accidents. They should also check the electricity cable attached to the crane and make sure no partial damage had occurred during operation. The operating area should be visible, keeping enough space for the movement of the crane while loading and unloading heavy construction material, the department said. Contractors should check the crane's break system to ensure its smooth operation. Speaking about mobile cranes, the CDD said contractors should make sure its crawlers do not have any obstacles that obstruct its movement and its parts are installed on the crawler tightly. "End stops must be provided on crane and hoist tracks and rails to prevent the equipment running off the end of the track or rail," the CDD said. Contractors should also check the speed of winds to ensure that it is at safe level, the statement said, adding that they should not operate cranes until the wind speed comes down to safe levels. Operator should also make sure the crane moves to all sides without carrying loads by moving its wings to right and left and moving the crawler to right and left. "If inspectors find anything wrong during tests, they should stop the crane's operation completely for maintenance works. Operators should inform maintenance engineers if they hear any unusual or strange sound from the equipment," the CDD said. In a previous statement, the CDD said tower cranes should be designed to withstand thunderstorms, must comply with the Kingdom's construction code and should have indicator lights to ensure aviation security and safety of the crane. Crane operators have also been told they must have adequate training, the necessary certificates, should wear protective equipment. Copies of operation and maintenance manuals should be made available to them.