Coaches will replace trains on the Warrnambool line for the next two weekends as V/Line continues upgrades to train detection technology at several level crossings between Warrnambool and Geelong. The upgrades at Winchelsea, Boorcan, Camperdown, Terang and Warrnambool will mean no trains will run on the line on Saturday, December 9, Sunday, December 10, Saturday December 16 and Sunday December 17. V/Line warned the coaches replacing the train services over the two weekends would depart Warrnambool line stations up to 25 minutes earlier than the normal scheduled train service. Coaches from Warrnambool will not stop at South Geelong or Marshall stations. Passengers travelling to these stations are advised to change to a Geelong Line train at Waurn Ponds. Services will also be interrupted on December 13 as transport workers take strike action against V/Line. Train and bus workers are due to walk off the job for four hours as part of a pay dispute with the regional train and coach operator. V/Line has been notified by the Australian Rail Tram and Bus Industry Union operations staff will take industrial action from 3am to 7am on Wednesday. The first train on the Warrnambool line departs the city's station for Southern Cross at 6.12am. Only non-driving grades will participate in the action, including conductors, train controllers, station and customer service staff and authorised officers, but the union says it will bring the entire V/Line network to a halt. V/Line said it was still working on arrangements for a replacement coach service on Wednesday morning. Meanwhile, for passengers travelling to Melbourne, coaches will replace trains on the Geelong line between between Wyndham Vale and Waurn Ponds. Melbourne-bound passengers will switch to the train at Wyndham Vale, with V/Line recommending people allow an extra 60 minutes for the journey.