1. Pratt Truss:
- This is a popular truss design commonly used in railway bridges.
- It consists of vertical members (posts) and diagonal members (braces) arranged in a triangular pattern.
- The diagonals slope downward from the top chord to the bottom chord.
2. Warren Truss:
- Another common truss type, the Warren truss, features a series of equilateral triangles formed by the top and bottom chords and the diagonal members.
- The diagonals alternate in direction, creating a zig-zag pattern.
3. Howe Truss:
- This type of truss is less common but still used in some bridges.
- In a Howe truss, the diagonals slope upward from the top chord to the bottom chord.
4. Petit Truss:
- Petit trusses are characterized by their curved top chords and straight bottom chords.
- The diagonals intersect at the center of the truss, forming a distinctive "W" shape.
5. K Truss:
- K trusses are a variation of the Pratt truss.
- They have an extra vertical member in the center of each panel, connecting the top and bottom chords.
- This additional member provides increased rigidity to the truss.
6. Parker Truss:
- Parker trusses are similar to Pratt trusses but have a different arrangement of the diagonals.
- The diagonals in a Parker truss intersect at the top chord, whereas in a Pratt truss, they intersect at the bottom chord.
7. Baltimore Truss:
- Baltimore trusses are a type of truss bridge commonly used in the late 19th and early 20th centuries.
- They feature a combination of Pratt and Warren truss elements.
These truss types are selected based on factors such as the bridge's span length, load requirements, and desired aesthetic appearance. Each truss type offers unique advantages and limitations, and engineers carefully consider these factors when designing and constructing bridges.
