Vic train strike to last only four hours

Melbourne commuters are bracing for more traffic chaos and public transport pain on Friday with a four hour train strike to go ahead.

The Rail, Train and Bus Union says the four-hour stoppages will proceed on Friday but key staff will stay on duty long enough to ensure disruptions are limited to between 10am and 2pm.

A similar four-hour stoppage was held last week on Melbourne's tram network, but services were unavailable for most of the day.

"We have made this decision to ensure that every train scheduled to commence before 10am can complete its timetabled run," RTBU State Secretary Luba Grigorovitch said in a statement on Monday.

"These staff will also return to work in sufficient time so that every train scheduled from 2pm onwards can run."

Train users are warned to make other arrangements if planning to travel between those times.