The elevator has remained largely unchanged since Elisha Otis introduced the first cable-dependent safety elevator in 1857. For over 160 years, buildings have relied on steel ropes, counterweights, and pulleys to move people between floors. But that paradigm is now shifting in a fundamental way. Engineers at ThyssenKrupp developed the world’s first rope-less elevator system, known as MULTI, which eliminates steel cables entirely and allows cabins to travel both vertically and horizontally within a single building. This breakthrough, highlighted alongside other pioneering developments in a roundup of the most interesting advances in construction technology, represents a complete rethinking of how people move through tall structures. By drawing inspiration from magnetic levitation railways rather than traditional hoist mechanisms, the rope-less elevator opens new possibilities for building design, traffic flow management, and operational energy efficiency.
How Linear Motor Technology Replaces Steel Cables
The core innovation behind rope-less elevator technology is the application of linear induction motors, similar to the systems used in magnetic levitation trains. In a conventional traction elevator, the motor rotates a sheave that grips steel cables to pull the car upward, and a counterweight balances approximately half the load. In the MULTI system, this entire arrangement is eliminated. Each elevator cabin is equipped with integrated linear motor drives that interact with electromagnetic guide rails embedded into the shaft walls. When electrical current passes through the motor windings, it creates a traveling magnetic field that propels the cabin upward or downward without any physical connection to a rooftop machine room.
The elimination of steel ropes and counterweights carries multiple benefits beyond freedom of movement. Counterweights typically account for roughly 40 percent of the total energy consumed by a traditional elevator system because the motor must accelerate and decelerate the combined mass of the car, the passengers, and the counterweight. In the rope-less design, only the cabin and its occupants need to be moved. The system further reduces energy demand through regenerative braking technology that captures kinetic energy when cabins decelerate and converts it back into electricity that feeds into the building’s power grid. Early field measurements indicate that this approach can reduce total elevator energy consumption by 30 to 40 percent compared with conventional traction systems. When integrating this technology into new construction, designers must also account for the unique structural loads created by multiple independent cabins moving through a single shaft, requiring careful attention to below-grade protection and foundation integration at the lowest levels of the building.
Multi-Directional Movement and Shaft Switching
The most striking feature of the rope-less elevator is its ability to move sideways as well as vertically. The MULTI system uses a network of interconnected vertical and horizontal shafts linked by transfer tracks, conceptually similar to the switching system of a railway yard. When a cabin reaches the top of a vertical shaft, it can slide horizontally along a track to an adjacent vertical shaft, then continue moving upward, downward, or reverse direction. This multidirectional capability allows the system to create a continuous loop of cabins that circulate through the building much like a subway line, with cabins entering and exiting the main loop to serve different floors.
The practical implications for building occupants are significant. In a conventional elevator bank, passengers wait for a single car to arrive, board, travel, and discharge. In the rope-less system, multiple cabins circulate continuously through the building network, dramatically reducing average wait times. The control software adapts to traffic patterns in real time, sending more cabins to high-demand floors during morning rush hour or redirecting empty cabins to waiting areas during lunch periods. Residential and mixed-use buildings can integrate this type of efficient vertical transportation to maximize livable space on every level, as seen in projects such as the Dogwood Ridge rustic home elevator floor plan, where a compact elevator core leaves more room for living areas.
Impact on Building Design and Shaft Efficiency
Traditional elevator systems impose rigid constraints on architectural design. Each vertical shaft must run continuously from the lowest floor to the rooftop, and the machine room consumes valuable space that could otherwise serve as premium penthouse floor area. The structural load of the machine room equipment also requires additional steel reinforcement at the top of the building. Rope-less elevators eliminate both the continuous shaft requirement and the rooftop machine room entirely. The linear motor drives are distributed along the guide rails in the shaft itself, so no separate equipment room is needed. This single change can reduce total building height by several meters while maintaining the same number of usable floors, translating into significant savings in structural materials, cladding, and mechanical systems.
The efficiency gains within the shaft are equally meaningful. In a conventional configuration, only one cabin can operate per shaft because the cables and counterweight physically occupy the space. The MULTI system can run three to eight cabins in the same shaft space, increasing transport capacity by up to 50 percent without increasing the building core footprint. This is especially valuable in high-rise urban towers where every square meter commands a premium price. The reduced structural demands of the rope-less system also pair well with lightweight construction methods such as cross-laminated timber for elevator shaft construction, further reducing the building’s embodied carbon footprint while maintaining fire resistance and structural performance.
Energy Efficiency and Regenerative Performance
Energy consumption has always been a weak point of traditional elevator systems. The counterweight arrangement balances loads partially, but steel ropes experience significant friction as they bend around the sheave and over deflection pulleys. The motor operates at a fixed efficiency curve regardless of passenger load. The rope-less elevator addresses these inefficiencies at multiple levels. The linear motor design has fewer moving parts and operates without mechanical contact between the drive and the guide rails, eliminating friction-related losses almost entirely. The absence of steel ropes also reduces the total moving mass that must be accelerated and decelerated at each floor.
The regenerative braking function deserves close attention from building owners. When a cabin slows down before reaching its target floor, the linear motor reverses its electrical phase and switches into generator mode, converting kinetic energy back into usable electricity. This regenerated power returns to the building’s internal grid in real time, where it can be consumed by other systems such as lighting, HVAC equipment, or other elevators that are simultaneously accelerating. Controlled tests of the MULTI system indicate that regenerative braking reduces total elevator energy usage by 30 to 40 percent compared with conventional traction elevators that dissipate braking energy as heat through resistor banks. These performance characteristics align with broader trends in modern elevator design and specification that prioritize sustainability and operational cost reduction alongside passenger comfort.
| Parameter | Traditional Traction Elevator | Rope-Less Linear Motor Elevator |
|---|---|---|
| Drive mechanism | Steel ropes around motor-driven sheave with counterweight | Linear induction motor along electromagnetic guide rails |
| Movement directions | Vertical only | Vertical and horizontal with switching tracks |
| Maximum cabins per shaft | 1 | 3 to 8 (independently operated) |
| Rooftop machine room | Required for motor, controller, sheave assembly | Not required (drives distributed in shaft) |
| Energy recovery method | Braking resistors dissipate heat | Full regenerative braking to building grid |
| Transport capacity gain | Baseline | Up to 50 percent higher within same core |
| Mechanical wear points | Rope fraying, sheave wear, guide shoe friction | Minimal due to non-contact electromagnetic drive |
Installation Challenges and Structural Considerations
Despite its advantages, the rope-less elevator introduces new challenges for construction teams. The electromagnetic guide rails must be installed with extremely tight alignment tolerances, typically within 2 millimeters deviation per 10 meters of shaft height, because the linear motor relies on a consistent air gap between the cabin and the rail surface. Any misalignment reduces the efficiency of the magnetic coupling and can introduce vibration during operation. The shaft infrastructure must also accommodate switching track mechanisms at transfer floors, which involve motorized diverters that redirect cabins from vertical travel into horizontal movement. These components require reinforced structural support at each transfer point and careful integration with the building’s fire compartmentation strategy.
- Guide rail alignment tolerance must be held under 2 millimeters per 10 meters of shaft height
- Switching track diverters at transfer floors require reinforced structural framing and fire-rated separation
- Electrical supply must deliver higher instantaneous power than conventional elevator drives
- Fire-rated shaft enclosures must account for horizontal openings at cabin transition points
- Commissioning involves sequential testing of each cabin’s independent navigation and collision-avoidance system
- Emergency evacuation procedures must address cabins stopping in horizontal shaft sections remote from floor landings
Construction teams working on buildings with rope-less elevator technology should elevate their safety protocols, as installation involves precise electrical work, heavy component handling, and coordination at height within confined shaft spaces. Proper job site first aid and construction safety practices are essential during every phase, from guide rail alignment through final commissioning. Electrical subcontractors must be familiar with high-power linear motor drives, which differ substantially from the variable-frequency drives used in conventional elevator motors.
Conclusion
The rope-less elevator by ThyssenKrupp marks a genuine departure from 160 years of cable-based elevator technology. By replacing steel ropes and counterweights with linear motor drives, the system enables multidirectional movement, increases shaft capacity, reduces energy consumption, and frees architects from the design constraints imposed by traditional elevator cores. The technology has progressed well beyond the prototype stage, with the first MULTI test installation completed in a 246-meter test tower in Rottweil, Germany, and projects planned or underway in commercial buildings across Europe and Asia.
For architects and engineers planning new high-rise projects, the rope-less elevator offers a compelling value proposition that can reduce core dimensions, increase usable floor area, and lower operational energy costs. As the construction industry continues to adopt innovative materials and methods, the parallel progress in sustainable materials including the use of borate wood preservatives for treated lumber demonstrates how the industry is innovating on multiple fronts simultaneously. As rope-less elevator technology matures and becomes more widely adopted, it has the potential to change not only how buildings transport people but also how buildings themselves are conceived, designed, and constructed from the ground up.