How to Choose a Heavy Fabrication Supplier and Plan the Freight
Choosing a fabricator for a multi-tonne weldment is not like choosing a machine shop. The decision is made almost entirely by equipment you cannot see on a website, and it is followed by a logistics problem that is frequently larger than anyone budgeted for.
This is the checklist we use, and the freight thinking that should run alongside it.
The five questions that filter the field
Ask these before anything else. They eliminate most shops in about ten minutes.
1. What is the crane capacity, in every bay?
Not the headline number. A shop may advertise 50 tonnes because that is what the main fabrication bay lifts, while the machining bay has a 15-tonne crane and the loading dock has 20. Your piece has to be liftable at every station it visits.
Ask for capacity by bay, and ask where the machining happens.
2. How long is the stress-relief oven?
If the oven is shorter than your piece, one of three things happens: the piece goes out to a subcontractor with its own transport cost and schedule risk, the shop proposes vibratory stress relief instead, or, the outcome to fear, nobody mentions it and the piece is machined without relief and moves afterwards.
Oven length is a hard number. Ask for it. Background in stress relief for welded machine bases.
3. What is the machining envelope, table size and travel?
A 6 m table with 4 m of X travel machines 4 m parts. Ask for both figures, plus the maximum workpiece weight the table takes, which is often lower than the crane.
4. Are the welding procedures and welder certificates current?
Not “do you weld to D1.1”, ask for the WPS, the PQR, and dated certificates for named welders. Details in AWS D1.1 in plain language.
5. What have they exported, and to where?
Export is a separate competence from fabrication. A shop that has only ever delivered to domestic customers may be excellent at welding and completely unprepared for a certificate of origin, a fumigation certificate for timber packing, or a packing list that customs will accept.
Ask for a recent shipment: destination, Incoterm, who did the documentation.
What a shop visit should verify
A video call shows you a tidy corner. A visit shows you the shop. What is worth looking at:
- The crane hook height: not just the capacity. Low hook height limits what you can turn over.
- Fixturing and turning gear. A shop with proper positioners welds in the flat position, which is faster and better. A shop without them welds overhead, which is slower and worse.
- Consumable storage. Low-hydrogen electrodes need heated storage. Open boxes on a damp floor tell you what the preheat discipline is like.
- The QC office. Is there one? Are there records in it? Can they find last month’s weld map in under five minutes?
- Work in progress. What is on the floor right now, and does it look like your kind of job?
The trial-job strategy
Do not make your first order with a new shop the critical one. Size the first job so that a failure is survivable, a single piece, a reasonable schedule, a scope that exercises the capabilities you actually care about.
What you are buying with the trial is not the part. It is the answer to three questions: did the dimensional report match the drawing, did the schedule hold, and when something went wrong, did they tell you before or after you asked?
Now the freight
This is where heavy fabrication projects go over budget. Plan it in parallel with the fabrication, not afterwards.
Container, flat rack, or breakbulk
| Mode | Rough limit | Cost behaviour |
|---|---|---|
| 40 ft standard container | 2.33 m wide × 2.35 m high internal | Cheapest, predictable |
| 40 ft flat rack | ~2.4 m wide, open top and sides | Moderate premium |
| Out-of-gauge on flat rack | Wider or taller than the rack | Charged for the slots it blocks |
| Breakbulk / project cargo | Essentially unlimited | Quoted per shipment, expensive |
The cost steps are not smooth. A frame that fits a flat rack ships at a predictable rate; the same frame 20 cm taller blocks the slots above it and can cost several times as much. The full treatment is in out-of-gauge and breakbulk shipping.
This is the single strongest argument for split-and-bolt frame design, which turns one out-of-gauge piece into two containerised ones.
Who owns the ocean leg
Decide the Incoterm before you compare quotes, or you will compare numbers that are not comparable. EXW, FOB and CIF put the cost and the risk in very different places, see Incoterms for heavy fabrication.
For a first order with an unfamiliar supplier, FOB is usually the sensible middle: the shop handles export clearance and delivery to the ship, you control the carrier and the insurance.
Packing is engineering, not an afterthought
Heavy weldments need designed packing: lifting points marked and rated, a cradle or skid that takes the load where the piece can carry it, lashing points, desiccant and wrapping for machined faces, and timber that meets ISPM 15 for the destination country.
Ask to see photographs of the packed piece before it ships. It costs nothing and it catches problems while they are still fixable.
The documentation pack
For a shipment out of Vietnam, expect to need:
- Commercial invoice and packing list
- Bill of lading
- Certificate of origin (Form B, or Form D for ASEAN destinations)
- ISPM 15 fumigation certificate for timber packing
- Mill certificates for the steel
- Weld map, NDT reports and dimensional FAI
The last three are quality documents rather than customs documents, but they belong in the same pack. If your QA will ask for them, specify them at RFQ stage, reconstructing a weld map after shipment is painful.
Putting it together
The fabricator decision and the freight decision are the same decision. A shop 40 km from a deep-water port with a 25-tonne crane may beat a better-equipped shop 300 km inland, once the oversize road permit is priced in.
That is the part we do. We do not own a shop, so the shortlist is built from what your drawing actually needs, crane, oven, machining envelope, weld standard, and the distance to the port. Send the drawing and we will come back within 24 business hours with the shortlist. The matched shops quote with the Incoterm fixed, so you can build the landed cost, not just compare ex-works prices.