Shipbuilding cost breakdown: block construction, the dry dock is the central asset
Costing a ship build the way modern yards actually work - block/section assembly, with the dry dock or slipway as the central fixed asset and launching as its own cost event, unlike general steel fabrication.
Modern shipbuilding doesn't weld a hull together in one place the way general steel fabrication does - the ship is divided into BLOCKS built in parallel across different areas of the yard, then joined together on a dry dock or slipway. This is the biggest structural difference from ordinary steel fabrication, and it drives how most of the categories below get costed.
The costing unit: ONE TON OF STEEL PROCESSED (or a specific block, when costing one block) - not "one ship", since every newbuild is typically a different design and doesn't repeat like a machined part.
The block-construction build sequence
- Steel nesting - planning the optimal cutting layout for plates from the structural drawings.
- Cutting & forming - plasma/gas CNC cutting, plate bending.
- Block assembly & welding - built in parallel across multiple areas of the yard.
- Early outfitting inside the block - piping, electrical, machinery installed while the block is still open (the earlier this happens, the cheaper - access gets much harder once blocks are joined).
- Erection - blocks are craned onto the dry dock/slipway and welded into the complete hull.
- Launching.
- Post-launch completion - interiors, remaining systems.
- Sea trials & handover.
Step 4 is where the biggest, most commonly missed saving lives: installing early while a block is still open and accessible is far cheaper than doing the SAME work after erection, when neighboring blocks block access.
Ten categories
1. Materials
Steel plate by ton, anti-fouling paint by liter, pipe and cable by linear meter. Convert to tons of steel processed using actual issued steel minus scrap cut away.
2. Equipment - mostly owned, unlike residential construction
Plasma/gas CNC cutters, automated welders, dock cranes - unlike residential construction (mostly rented by shift), shipyards typically OWN this equipment as fixed yard infrastructure because the investment is too large to rent. Depreciated over useful life, allocated across tons of steel processed per year.
3. Dry dock/slipway - the central fixed asset, costed separately from overhead
This is the industry's most distinctive item: the dry dock or slipway is a large fixed asset, and how many days a given ship occupies it directly determines how many ships the yard can build per year. Allocate dock depreciation by DAYS this ship occupied the dock, not evenly by tonnage - two ships of the same tonnage but different design complexity occupy the dock for different lengths of time and should carry proportionally different dock cost.
4. Labor
Welders, fitters, supervising engineers - costed by actual hours per block, plus erection and post-launch completion hours.
5. Scrap - offcut steel
Excess steel from nesting that doesn't go into any block. Compare issued steel against steel that actually ends up in the hull (per drawing) to get an accurate rate; scrap resale can recover part of the cost.
6. Consumables
Welding rod, plasma/gas cutting consumables, grinding discs - divided by weld length or cut length achieved before replacement, same tool-life logic as any other trade.
7. Subcontracted work - main engine and specialized marine equipment
The main engine, radar, autopilot systems are typically bought from specialist suppliers and only installed at the yard, not fabricated in-house. Cost at actual purchase price, converted to tonnage or costed per specific ship.
8. Rework - weld defects found by inspection
Welds that fail non-destructive testing (NDT - ultrasonic, radiographic) have to be re-welded. Track rework rate by welding team separately to identify where skill improvement is needed, rather than blending it into material scrap.
9. Packaging - small, nearly absent
No packaging in the usual sense. Kept short here because it genuinely is small in this industry.
10. Freight - moving blocks within the yard, not shipping to a customer
Specialized cranes/transporters move blocks from the fabrication area to the erection site - INTERNAL yard freight, unlike shipping a finished product to a customer in other industries. The finished ship moves under its own power at handover, with no freight charge like other products.
Site overhead (excluding the dock - see category 3)
Project management, project insurance, general yard safety. Entered per month or phase, allocated by tonnage or by project.
Related guides
- Residential construction cost breakdown: all ten cost categories, in build order
How to cost a residential construction work item properly - materials, equipment, labor, waste, subcontractors, rework, freight and site overhead - and why no two projects are ever the same size to compare directly.
- The Ten Manufacturing Cost Categories, in Production Order
The ten cost categories Costdown uses to price a product — material, machinery, labor, tooling, scrap, rework, outsourced processing, packaging, logistics, factory overhead — with the formula and a worked example for each.
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