Freight Wagon Chassis (Underframe) Structural Design

Full structural design and fabrication-ready drawing package for a 4-axle tank-wagon chassis/underframe, from concept through issued-for-fabrication (IFF) drawings. Design only — no prototype build, no homologation/type-approval execution (may be scoped separately).

**Key parameters**
Parameter Value

Payload 40 t
| Tank capacity | 48 m³, SS304, mounted on chassis (tank design excluded — interface only) |
| Gauge | 1,435 mm standard |
| Axle config | 4-axle (2 bogies) |
| Program size | 150 units (design must be series-fabrication-ready, not one-off) |
| Code basis | EN 12663 (structural), EN 13749 (bogie frame strength — if bogie also in scope, confirm), EN 15085 (welding) |
| Fabrication site | ARESCO Helwan facility — 300,000 m² yard/production, 36,000 tpa capacity, heavy fabrication certified (pressure vessels, heavy structures) |

**Deliverables**
1. Structural design basis report (loads, load cases, material selection, FEA/hand-calc structural verification per EN 12663)
2. Weight/mass budget closing tare, axle load, and payload consistently (single verified value — no cross-sheet conflicts)
3. General arrangement (GA) drawing
4. Chassis/underframe fabrication drawings (weldment details, plate schedule, welding symbols per EN 15085)
5. Bill of Materials (BOM) reconciled with weight budget
6. Bogie interface drawing (bogie itself may be sourced off-the-shelf — coordinate mounting/coupling interface only, unless bogie design is added to scope)
7. Coupler/draft-gear and anti-accident device interface points (shelf coupler, anti-climber, BOV skid — interface dimensions only; these are underframe-integral items and must be shown, not separately supplied)

**Explicitly excluded**
- Tank vessel design (ARESCO in-house scope)
- Bogie internal design (unless separately agreed)
- Type approval / homologation testing and certification liaison

**Candidate profile**
- Demonstrated rail rolling-stock structural design experience (freight wagon or tank wagon underframe), EN 12663/13749 fluency
- Able to work from ARESCO-supplied GA/interface constraints and iterate against Helwan fabrication capability (plate sizes, welding process, handling limits)

**Format / commercials to add before posting**
- Fixed-price or hourly — recommend fixed-price milestone-based (design basis → GA → IFF drawings) given single deliverable, defined scope
- Timeline: suggest requesting freelancer's proposed duration; typical range for this scope is 6–10 weeks for one qualified rail structural engineer
- Platform (Upwork/LinkedIn/rail-specific boards e.g. Railway Gazette job board)?