In the case of a truss bridge, a post-tensioned slab bridge, or a box girder bridge the sections are often floated to the bridge and then lifted into place by cranes on barges or cranes sitting over piers.
The very good reason why the word communism is so commonly associated with these revolutionary, anti-liberal, anti-democratic Marxists is that political parties with communist in the name were pretty much invariably of that bent throughout the 20th century, whereas parties called socialist or social democrat or labor varied enormously in ideology.
In its modern form, communism grew out of the socialist movement of 19th-century Europe. As the Industrial Revolution advanced, socialist critics blamed capitalism for the misery of the proletariat âa new class of urban factory workers who labored under often-hazardous conditions.