Direct Answer
Long-span structures (trusses, long-span beams, transfer girders spanning 60+ feet) present unique fabrication challenges: member lengths may exceed standard mill lengths (requiring field splices), camber is critical and must be precisely engineered, transport length and weight may require permits, and precision in truss chord alignment is essential for proper geometry after erection.
Full Explanation
Long-span fabrication considerations: (1) Mill length limits — standard W-shape max length is typically 60–65 feet; longer spans require field splices or special-order lengths from the mill. (2) Camber — for long-span beams, dead-load deflection can exceed 2–3 inches; camber must be specified and verified precisely. (3) Transport — beams over 60 feet or over-legal-weight require permitted loads (pilot car, restricted routes, time-of-day restrictions). (4) Truss geometry — welded trusses must be laid out on a precision assembly jig; even 1/8" error in chord alignment compounds over a 100-foot span to create meaningful geometry deviation. (5) Camber jigs — some long trusses require an inverted jig that holds the truss in the cambered position during assembly welding.
What This Means for Your Shop
Long-span structural work is a specialty that not all shops can handle. Precision jigging, extended transport logistics, and camber management require experience. Know your shop's long-span capability before bidding.
Common Mistakes
Not verifying that your shop can handle the length of the longest member before bidding. A 80-foot truss chord won't fit in a shop with 60-foot crane coverage — a problem discovered after signing a fixed-price contract.
Recommended Process
When bidding long-span work, verify: (1) Your cranes' lifting capacity for the heaviest assembly. (2) Your shop floor length for the longest member. (3) Your cambering capability for required camber. (4) Your transport arrangements for over-length members. Price these constraints before committing.