Tyler's grandmother, Sue Stephens, of Thames, was also on the train and said she got a fright, but was proud of Tyler, who did not cry.
Titirangi mother-of-three Meriel Fawcus witnessed the crash.
" They had uncoupled the engine and then they backed it up but it bumped into the carriages really hard. It gave them all the biggest thump. There was mass crying going on down the train and quite a few people got off."
Fawcus estimated the train included about five carriages and all were full.
Organisers rushed on to the train, including one person who ran through the carriages to check for injuries, she said.
Glenbrook Vintage Railway general manager Neil Carey said the crash was a minor shunting incident, which jolted a carriage.
Seven people were injured when a miniature rain derailed in Hawke's Bay last month.