Middle Atlantic RIB-3-MRK-42 3-Bay Riser Base for MRK 42-Inch Deep Racks
Overview
The RIB-3-MRK-42 is a three-bay riser base designed to elevate and level Middle Atlantic rack enclosures in finished equipment rooms, server closets, and AV infrastructure deployments. At 2.5 inches tall and 66.06 inches wide, it spans three side-by-side bays — giving you a unified, floor-level foundation that lifts the rack array just enough to clear cable management runs, leveling feet, or raised floor penetrations without consuming usable rack space. If you're installing a multi-bay Middle Atlantic rack system and need a clean, stable base that keeps the assembly off the slab while maintaining structural alignment across bays, the RIB-3-MRK-42 is the purpose-built solution. It ships at 60 lbs, so plan for two-person handling during rough-in.
Compatibility
The RIB-3-MRK-42 is engineered specifically for rack enclosures in the Middle Atlantic MRK and VRK series at 42-inch depth. It is a three-bay unit — sized to support three adjacent MRK or VRK rack columns installed side by side. It is not interchangeable with shallower rack depths (e.g., 24in or 36in MRK/VRK variants) or other Middle Atlantic rack families outside the MRK/VRK line. Verify your rack depth is 42 inches and your bay count is exactly three before ordering; Middle Atlantic offers single-bay and two-bay RIB variants for other configurations within the same rack accessories line. This base does not substitute for seismic anchoring — consult local code requirements for installations in seismic zones. For full rack rack planning, confirm floor load ratings where applicable given the 60 lb shipping weight of the base alone, before adding populated rack weight.
Installation Notes
The riser base measures 66.06 inches wide × 42 inches deep × 2.5 inches tall. Confirm floor clearance and door swing radius account for the full 42-inch footprint depth before positioning. The 60 lb shipping weight suggests cast or heavy-gauge steel construction — use appropriate lifting technique during positioning. No fastener torque specs or tool requirements are published in available evidence; follow Middle Atlantic's installation guide included with the unit.
