RE: Invasion pics from a rainy 2007 version had an operating Steam Shovel at the museum.
I have some nice pictures of the parking lot side and there is NO brakewheel or lever evident.
I did see gears underneath between the 2 trucks so possibly the crane has no brakes in the usual way on the wheels but only on the gear mechanism.
Built 03/1919, now with Central Vermont paint, made by Industrial Works Builders, Bay City, Mich.
Next Invasion, this year, I am going to go visit the crane again and see the other side and find out for sure! Unless you go over there yourself first and find out for both of us!