
Bridges: would come in many models with different usage and need of heavier forged materials but take a lot of them for constructing them.
the 3 types would be simple bridges made of wood and concrete these can use modules like water mills, dams, drawbridges, floodgates, ports for shipping, and many others. then there are the more complex bridges which can be made for crossing cliffs, mountains, buildings, and even linked to stairwells, and archways.
the last one is a rope bridge that could later be used for things like tree house platforms and to cross pits in caves and mines.
Cranes: would come in 3 model types for loading and unloading, excavation and drilling, and architecture construction.
places to construct a crane would be usually on a concrete base or on top of scaffolds then later models can be erected on top of tall structured buildings or cliffs for use of excavation on higher reaches.
Barges: would be another way for traveling in water or to sea transport to other continents or islands. barges can travel in water only but can be lifted by bigger cranes for transporting elsewhere.
Crates: would ideally weigh a ton so it would hold a bunch of furniture or chests or even big barrels that you could not lift without a Dolly or Carriage-Waggon which is essential for land transportation.