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.
communism definition. An economic and social system envisioned by the nineteenth-century German scholar Karl Marx. In theory, under communism, all means of production are owned in common, rather than by individuals (see Marxism and Marxism-Leninism). In practice, a single authoritarian party controls both the political and economic systems. In the twentieth century, communism was associated with the economic and political systems of China and the Soviet Union and of the satellites of the Soviet Union. (Compare capitalism and socialism.)