MULTI-PIECE DATUM RAIL

A fuel cell system includes end covers, beam-like datum rails extending from one end cover to an opposite end cover and engaging in interference fit with the end covers. Bipolar plates (BPPs) are stacked between the end covers. The BPPs have locating features sized and shaped to slidingly engage with the datum rails. The datum rails align the BPPs with corresponding electrical, fluid, and mechanical features formed in the end covers. Each datum rail includes two or more modular datum rail portions having locating pin receivers formed axially in ends thereof. Locating pins are disposed within the receivers. Each rail portion is connected to at least one other rail portion via the plurality of locating pins. At least one rail portion is connected to each end cover, and to at least one other rail portion via locating pins.