A Fink truss is a triangular truss whose internal members form a W shape. The system is named after the German-American engineer Albert Fink (1827–1897) and is widely used as a roof truss or bridge truss. The W configuration distributes loads efficiently across the members, enabling large spans with relatively light sections.
Geometry
A typical Fink truss consists of:
- Bottom chord (tension) — horizontal member below
- Top chord (compression) — two sloping members forming the triangle
- Central vertical — from the ridge to the centre of the bottom chord
- Diagonal web members — in a W pattern between top and bottom chords
- Joints (panel points) — connected by bolts or welds
The W configuration ensures that most members are loaded in pure tension or compression — efficient use of material.
Application
Fink trusses are used in:
Roofs
- Industrial halls — large clear spans of 12–30 m
- Sports halls — over gyms and swimming pools
- Warehouses and sheds — economic roof truss
- Agricultural buildings — barns, stables, hay sheds
- Carports and canopies — smaller spans
Bridges
- Classic railway bridges in the USA, designed by Albert Fink himself
Benefits
- Low material demand — efficient force distribution
- Lightweight construction — less load on bearing walls
- Large spans possible without intermediate supports
- Prefabrication friendly — fast site assembly
- Flexible design — scalable to project size
Materials
Fink trusses can be made of:
- Steel — most common, rolled sections or hollow profiles
- Timber — in timber frame, residential and agricultural construction
- Aluminium — for lightweight, corrosion-resistant spans
- Glulam — for large, architecturally exposed spans
Comparison with other trusses
In addition to the Fink truss, other forms exist:
- Howe truss — verticals in compression, diagonals in tension (reverse)
- Pratt truss — diagonals point toward centre, mainly in tension
- Belgian truss — similar W pattern, different node layout
- English truss — mainly with diagonals
Related terms
- Truss
- Lattice
- Belgian truss
- Pratt truss
- Dutch truss
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