The single most schedule-critical and irreversible event in an imaging project is moving a multi-ton modality from a truck to its final position and, for MRI, energizing a superconducting magnet that will not be powered down again for years. This article covers the physical logistics of delivery and rigging for heavy imaging equipment and the specialized magnet installation, cryogen fill, and ramp-up sequence unique to MRI. It is the activation step that sits between a built-out room and the downstream work of acceptance testing, physics survey, and the standing MRI safety program — those are handled by sibling Articles and are out of scope here except where they constrain the rigging plan.
Imaging modalities are among the heaviest and most delicate single pieces of equipment a hospital installs. A 1.5T or 3T MRI magnet typically weighs in the range of 4,000–6,000 kg before cryogen fill; a CT gantry runs 1,800–2,700 kg; a fixed C-arm angiography system, a PET/CT, and a linear accelerator are all comparably heavy and dimensionally awkward. These units arrive crated or shrink-wrapped on flatbeds, often direct from an overseas factory through a port, and they must travel an unforgiving path: off the truck, across grade or a dock, through the building envelope, down corridors, around corners, sometimes up or down floors, and finally into a finished room — all without exceeding floor-loading limits, striking finished surfaces, or damaging the equipment.
What makes rigging a true milestone rather than a routine delivery:
Because of this, the rigging plan is not a delivery-week detail — it is a design-phase deliverable that the manufacturer, the owner's vendor, the rigger, the structural engineer, and the general contractor develop and freeze well before the room is enclosed.
The governing artifact is the manufacturer's site planning / pre-installation guide, issued for the specific model and configuration. It specifies equipment weights and perspectives (crated and uncrated), required clearances, environmental conditions, power and cooling, the magnetic fringe field (for MRI), and — critically — the largest indivisible component that must be moved as one piece. The route must accommodate that largest piece, not the average.
A formal rigging study (often produced by the rigging contractor and reviewed by the structural engineer) typically establishes:
| Element | What it resolves |
|---|---|
| Delivery route | Truck staging, off-load point, building entry, every corridor, turn, and doorway from entry to room, with measured clearances vs. the largest component |
| Temporary opening(s) | Whether a wall, window, roof, or floor section must be removed and reinstalled; size, location, and structural make-safe |
| Lift method | Crane pick vs. forklift vs. air casters/skates vs. mechanical rollers vs. gantry/come-along; pick weights and radii |
| Floor protection & load path | Plywood/steel plate load-spreading, shoring of the slab below, and verification against floor-loading limits |
| Set & level | Final positioning over the equipment pad or isolation pads, leveling tolerance, and anchorage |
| Schedule & sequence | The window relative to construction (open-shell vs. enclosed delivery), trade clearances, and the manufacturer's install crew dates |
A central design decision is open-shell ("fly-in") delivery versus an enclosed route. For large magnets and linacs it is common to rig the unit in early — while the building is still open to the structure — through a temporary roof or exterior-wall opening using a crane, then build the room around it. This avoids the impossibility of threading a 5-ton magnet through finished corridors and tight doorways. The alternative, an enclosed route, demands that every corridor width, door opening, ceiling height, and turning radius along the path be verified against the crated perspectives, and that finishes either be installed after delivery or be protected. The choice drives the construction sequence: if fly-in is chosen, the magnet set date becomes a hard constraint that the entire structural and envelope schedule must hit.
Heavy modalities impose two distinct structural demands that must both be satisfied: the static service load of the equipment in operation, and the transient rigging loads during the move. Both are governed by the structural design of record under the International Building Code and the project's structural engineer, with the manufacturer's load data as the input.
For below-grade or upper-floor rooms, the load path includes elevators and floor penetrations. Equipment that exceeds elevator capacity, cab perspectives, or hoistway limits forces a crane pick or a temporary floor opening — a decision that must be made in design, not at the loading dock.