as part of the competitive tendering process, in early 1912 contracts were signed with each of peacock and co. of the uk, baldwin locomotive works of the usa, walkers limited of maryborough, queensland and austral otis, to compare against the cost of building engines at newport workshops. richie bros of sydney had also tendered but failed to win any of the orders. the contracts were for 20 engines each, with rights to a 20-engine extension and the possibility of up to a total of 100 engines. respectively, beyer, peacock and co. delivered engines 531-569, baldwin delivered 571-609 and newport 611-649 (plus tank engine 719) in 1912. the following year saw walkers delivered 651-689 while newport supplied tank engines 721-749. austral otis encountered difficulties and withdrew from the contract in november 1912, leading to that contract being re-offered.