THEY don't take sick leave or smokos and their manners are impeccable. But the newest employees at Sydney's Royal North Shore Hospital did not attend the staff Christmas party.
For the past month, these automated guided vehicles have been going about their work, transporting the heavy trolleys of linen and food throughout the hospital's new main building and politely telling anyone who gets in their way to ''please step aside''.
Let me through, I'm a trolley
Shocking and appalling: PM
Prisoners riot in NT
Detention footage 'hadn't piqued my interest'
Zara owner accused of plagiarism
Cutting tax breaks for the wealthy
CCTV: would-be thieves bungle Carlton North ram raid
Let me through, I'm a trolley
They don't take sick leave or industrial action. Meet the newest, ultra-polite employees at Royal North Shore Hospital.
There are 13 of the machines, which communicate with the building via Bluetooth and GPS technology.
The hospital is the first in Australia where the technology has been built into the fabric of the building.
The hospital's general manager, Sue Shilbury, said the machines delivered about 2000 meals a day for patients and carried 25,000 kilograms of linen. Another major benefit of the $4 million system was that it helped free staff to focus more on patient care.
''It has enormous benefit for the individuals working in the hospital in that it removes a lot of the repetitive manual handling tasks, which does lead to injuries, so it provides a safer working environment,'' she said.
The vehicles manoeuvre underneath trolleys before attaching to them via magnets. They communicate with the building, telling doors when to open and lifts when to stop.
Darryl Prince, the director of people and culture at ISS Australia, which is implementing the system, described the technology as ''very clever''.
''The food operator or the linen operator will order the AGV by putting the card [with a computer chip] in the call spot, a bit like you'd call for a taxi,'' Mr Prince said.
''The AGV will then pick that up through its wireless technology, zip up through the relevant station and then wait. It then sends a note through the paging system to tell the operator to say: 'I'm here and I've either got food with me or I'm an empty AGV ready to pick up whatever it is you want me to take.'''
The machines have little contact with the public, operating mostly behind the scenes. They move at walking pace and sensors prevent them bumping into walls and people's legs. They also warn people when they are approaching with the words: ''Attention, automatic transport. Please step aside.''
However, during Fairfax's visit, one vehicle ran over the photographer's foot, while another could not detect a bed being wheeled by as the bed height was above its sensors.
Project manager David Newman admitted the machines had ''a slight blind spot'' but said there had been no problems in the past month.
Ms Shilbury said the machines had raised eyebrows in the hospital.
''People have been fascinated,'' she said. ''They've really captured people's imagination. A lot of people have been making comments about bumping into machines that have asked them to 'mind the vehicle'.''