Reverse engineering of train braking systems

The CC2200 and CC3300-AC are veteran locomotives in CAMRAIL's fleet, and original spare parts are no longer on the market — every failed brake triangle became a maintenance crisis. A team of four was tasked with reproducing two functional units from locally available materials and tooling, matching the originals closely enough to drop straight into service, while transitioning from SMAW to MIG-MAG welding for higher structural standards.

My responsibility was every detailed 2D drawing and 3D model — holding dimensions and tolerances within manufacturable limits while guaranteeing compatibility with the original interfaces. For the CC3300 we used bent-and-cut UPN profiles with end caps to reach the right mass and diameter; for the CC3300-AC, rectangular iron bars machined into circular forms. Throughout, traditional reverse engineering — calipers, tapes, geometric analysis, tolerance verification — iterating closely with the machinists so what was drawn was actually buildable with the machines on hand.

Both brake triangles were manufactured, assembled and validated — the CC3300-AC unit completed the full Douala–Yaoundé route under real operating conditions. The lasting lesson was about the limits of design-office thinking: tolerances that assumed unavailable workshop capabilities cost rework, and consulting the manufacturer before finalising dimensions resolved it fast. The designer and the manufacturer aren't opponents in a tolerance negotiation — they're collaborators on the same problem.