139-18175 viewsBallarat, Doveton Street Sidings, weigh bridge test truck, WTT type four wheel weighbridge test waggon WTT 21, converted from IA type four wheel open waggon IA 7448. Started life as I type I 7448 built by Newport Workshops in January 1905, to IA type in 1935, converted to WTT type in April 1956.