Queensland Rail has put two more of its trouble-plagued New Generation Rollingstock trains into service.

Chief executive Nick Easy said the locomotives were rolled out on the Gold Coast and Airport lines on Monday.

“This is another positive step in the rollout of the NGR program and delivering a modern, world-class rail network for southeast Queensland, including in the lead-up to the Commonwealth Games in April,” he said in a statement on Tuesday.

“We expect to continue to deploy further NGR trains in the coming months as further trains are deemed ready for service after completing comprehensive testing and safety assessments.”

The first batch of the troubled trains started carrying passengers on the network on December 11.

Two of them were put into service on the Gold Coast and Airport lines, while one was held in reserve.

It takes the total number of NGR trains being used to just five, compared to the 75 that were ordered.

The state government halted the contract with Canadian manufacturer Bombardier in 2016 amid concerns over problems with the new trains, including line-of-sight issues, braking and disability access.

Mr Easy has previously said some of the trains had to be modified in Australia because they had been built before the issues were identified, while the others would be fixed during construction.

By Shae McDonald