A classic runway incursion. Seems that Airservices never read ICAO Doc. 9870, (Manual on the Prevention of Runway Incursions), where it says the following:
Doc. 9870 Para 4.2.6
All communications associated with the operation of each runway (vehicles, crossing aircraft, etc.) should be conducted on the same frequency as utilized for the take-off and landing of aircraft.
Doc. 9870 Appendix A Para 1.6.
To maintain high levels of situational awareness, it is also recommended that communications for all operations on a runway (landing, departing and crossing aircraft, vehicles crossing and runway inspections, etc.) take place on the VHF channel assigned for that runway.
Doc. 9870 Appendix C Para 4.3.
Communication with any aircraft related to the use of a runway for the purpose of taxiing should be transferred from the ground controller to the aerodrome controller prior to the aircraft entering or crossing a runway.
Standard Threat & Error Management principles dictate that an aircraft, (or a vehicle or tow) on a runway which is not on the same frequency as everyone else operating on that runway is a threat. How do you manage this THREAT? Everyone should be on the same frequency.
I worked ATC in Adelaide for 18 years and Hong Kong for 27 years on Tower and Approach. The simple fact of having all operational aircraft and vehicles on the same Tower frequency in Hong Kong, has saved many possible incidents from occurring over the years, because it adds to the situational awareness of everyone using the runway. Hong Kong has dozens of runway crossings every day by freighters, business jets and tows as the Cargo and Bizjet aprons (ramps) are South of the South runway. All are held short of the runway and call Tower South before being cleared to cross. It also does away with excessive coordination between the Tower Controller and Ground Controller and the timing of any cross can be more finely tuned.
You would think Airservices, (Civil Aviation Authority in those days), would have learned their lesson as far back as 1990 with a near collision between a departing Cathay 747 and a runway crossing tow. The report had a number of recommendations, the first being......
"1. The complete runway complex remain under the jurisdiction of the aerodrome controller (ADC) during SIMOPS and Multiple Runway operations;"