"The driver put the brakes on, and all the brakes worked, it's just that the wheels didn't have enough grip on the track to give them full effect," he told AAP.
"It's something that needs to be checked in a bit more detail."
The commissioner said older trains tended to have tread brakes, like bicycle brakes, which cleaned the wheels as they braked.
The train involved in the accident had newer disc brakes.
"They are more efficient at applying pressure to the wheels, but don't clean them if they've got slippery goo on them," Mr Dolan said.
"While we don't want to speculate too much, tread brakes might have reduced the risk of an accident like this happening."
The ATSB will also look into the train's anti-slip mechanism, which did not work properly before the crash.
The final report on the accident is due by the end of this year.
Queensland Transport Minister Scott Emerson said the report was a wake up call for Queensland Rail, but as there had been no catastrophic brake failure the government would focus on inspecting tracks for black spots.
"QR will now look to identify black spots where potentially this could happen," he told reporters.
Drivers will also be trained to handle such emergencies.
- AAP
