the below is just one of the trailers, it has two steam engines on it
Big Lizzie had a Blackstone single-cylinder engine that delivered 60 horsepower at 275 rpm, running on a mix of diesel and crude oil. It was cooled by water, and had an exhaust-induced airflow "radiator" that Bottril had designed. The 7 feet diameter flywheel weighed three tons, and the entire engine weighed eight tons. The tractor was 34 feet long, 11 feet wide and 18 feet high. Big Lizzie included a blacksmithy and anvil mounted on the foredeck. The total weight was 45 tons.
Botrill's patented wheels were also used on "Big Lizzie", a huge traction engine which McDonald's built to his design in 1915. Big Lizzie could carry almost 90 tons when two trailers were attached. There were just six bearers on each wheel, compared to Bottril's earlier designs which had as many as twelve bearers. This placed more strain on the cables retaining the bearers, and had the effect of reducing the tractor's speed to one mile per hour. Big Lizzie was awkward to maneuver, with a turning radius of 200 feet.
Bottrill planned to drive Big Lizzie to the Broken Hill mines, with two pedrail-equipped wagons in tow. He left Melbourne early in 1916, taking his family with him. He traveled at a maximum speed of 1 mph, going off road where bridges were not strong enough or the road bends were too sharp
From 1920 to 1924 Bottrill worked in Red Cliffs, in the Rural City of Mildura, clearing the ground for a 6,000 hectares (15,000 acres) irrigated farming settlement for World War I veterans. Up to 16 men helped attach cables to trees and stumps which Big Lizzie then hauled out.
above info from http://en.wikipedia.org/wiki/Frank_Bottrill
She was rescued in 1971 by the Redcliffs Big Lizzie Preservation Committee who restored her and settled her in her final resting place.K.N McDonald has recently located the missing second trailer and this has now been sent to Mildura for restoration http://www.oldengine.org/members/kennedy/mcdonald/docs/biglizziedet.htm
learned about it on http://steampunkvehicles.tumblr.com