By 2050, it is plausible that two out of every three people will be living in cities or other urban centres. That means there could be 2.5 billion more people in urban areas by the middle of the century, making efficient mobility in buildings no longer a luxury but an absolute necessity.

Designed to the highest German standards to ensure maximum passenger safety, TK Elevator’s TWIN is the only elevator system with two cars that move independently in one shaft, making the most efficient use of available space, reducing energy use, and minimising total time to destination, while always keeping people (billions of them) safely on the move. TWIN is most suited for premium high-rise buildings, both new installation and modernisation, with successful stories from around the world.

Why TWIN?

TWIN takes mobility to the next level by intelligently running two cars independently within the same shaft. The result is fewer shafts for more cars and a big increase in capacity. Unlike double-decker elevators, TWIN accommodates variable floor heights, and cars only stop at those floors on which passengers needed to embark or disembark. The implication is that TWIN offers more flexible building design options and significantly improves energy efficiency, while boosted by the option to park empty cars during periods of low-traffic demand.

TWIN is space-efficient for new installation and modernisation

How reliably can two cars run in the same shaft?

Each of the cars is controlled by its own respective equipment, including counterweights, ropes, traction drives, controllers and governors. But although each of the two cars in the same shaft has its own machinery, it is important to keep in mind that they will still use the same landing doors and guide rails. The reliability has been recognised with a TÜV-tested safety certification to meet even the strictest specifications and requirements.

TWIN is safe and credible

How efficient is TWIN?

The two-in-one design enables vertical transportation of almost twice as many passengers without needing to leave extra space for the other shafts that would normally be required. That effectively means that the number of shafts that a building needs can practically be reduced by half with TWIN, saving money and time by keeping more of the building’s leasable and usable space while optimising construction costs.

Shorter wait times, less traffic and fewer complaints inevitably lead to more satisfied tenants. TWIN comes with an intelligent Destination Dispatch Control system called AGILE. This digital solution, by intelligently gauging traffic demand and groups passengers together based on their destination floor, guarantees reduced wait times and less crowding in lobby areas. This not only increases traffic flow and allows tenants a quicker commute but can transport as many as 40% more passengers than other elevator systems.

How is the energy consumption of TWIN?

One of the most distinctive qualities setting TWIN apart from the others is the incredible amount of energy that it saves. While one of the cars are parked, the other car can remain in operation during non-peak hours — this can significantly reduce the amount of energy used.

For example, if an office building is less busy on the weekends and largely devoid of its 9-to-5 commuter population, the elevator control system will set commands for one car to stay stationary, while the other carries passengers to their destination.

TWIN also provides the option of enabling an energy recovery function to feed back about 30% of its energy generated through braking into the building’s power grid. This regenerative drive will further contribute to the decrease in energy consumption.

Can TWIN be installed in an existing building?

TWIN can positively be installed in a building that already has an elevator system in place. The marvelous thing about TWIN is that it can be installed as part of a modernisation project.

TWIN is industry-first with worldwide applications, including in various locations in China

Case Study: Universität Stuttgart, Germany

In this first-ever TWIN use-case in 2003, a building located at this University had an elevator system that was unable to cope with the growing number of students. The building was “underlifted”, namely, with not enough elevators to meet the high traffic demands. With the ultimate objective to increase elevator capacity without significant modifications to the building, TWIN was the perfect solution to increase handling capacity by up to two-fold while maximising usable floor area, without requiring additional shaft space.

Case Study: Bayshore Hotel, Dalian, China

Under a modernisation project completed in 2012, the Bayshore Hotel in the coastal city of Dalian needed to replace three of its eight existing elevators because of the steadily growing volume of passengers. Long waiting times and full cars – especially in the mornings and evenings – had resulted from that growth. The installation of two TWIN with a total of four cars, one new conventional elevator and the Destination Dispatch Control system in the five-star luxury hotel with 403 rooms and suites allowed the transportation of significantly more passengers per hour without needing more space or alterations to the building. The Destination Dispatch Control system played a central role in improving traffic flow and has a positive effect on energy consumption by minimising the number of empty trips made by the cars.

Case Study: Hong Kong Sanatorium & Hospital (HKSH) Proton Therapy Centre, Hong Kong, China

TWIN was selected as the future-proof solution to preventing the Centre from experiencing the same mobility issues as other similar facilities did, where a great number of patients, visitors, and staff travel between floors frequently, resulting in an overloaded elevator system and the need for dedicated personnel who can manually control the elevators. Starting operation in 2023, TWIN has been providing critical vertical transportation for patients in the first proton cancer treatment facility in Hong Kong.

Case Study: St. Botolph Building, London, United Kingdom

This building has an open atrium with eight elevator shafts. Without TWIN system, the building would have needed 14 elevator shafts to carry its 5,000 occupants. Because the 16 cars in the eight elevator shafts are visible, passengers can see them moving up and down those shafts, alleviating the concern that, sometimes, one car would be delayed waiting for the other in the same shaft.

Case Study: 50 Hudson Yards, New York City, the United States of America

The building developer compared TWIN to double-decker elevators where upper and lower cars are connected and move together. Double-decker elevators did not suit 50 Hudson Yards well, since the building design called for several double-height floors to accommodate trading rooms or public spaces. Besides, with double-decker elevators, when the upper car is loading, the lower car simply stops.

Case Study: Lusail Plaza Towers, Doha, Qatar

TWIN is adopted in Lusail Plaza Towers to enhance design flexibility and user experience. With two cars operating independently in one shaft, TWIN reduces the elevator footprint, adapts itself to future traffic patterns, and enhances efficiency with AGILE. This project has been honored with a Council on Tall Buildings and Urban Habitat’s 2024 Award of Excellence – Systems Award.

Celebrating 20 years of engineering excellence

Since its launch in 2003, TK Elevator’s TWIN has opened up new building design concepts for architects, as is evident from the numerous successful stories from around the world. Today, TWIN is still the only elevator system with two cars that move independently in one shaft. TWIN is in its fourth generation, featuring the most advanced safety system in the series yet. This system enables a speed of up to 8 m/s and a travel height of almost 300 m, making it possible for us to pursue the latest and greatest projects around the world with confidence in the safety and reliability of our elevators.

In a sprawling city like Hong Kong, TK Elevator’s mechanical engineers can be said to be the backbone. Their expertise and commitment not only elevate people-moving technology, rendering Hong Kong more livable and more competitive, but also ensure safety, reliability, and efficiency. TK Elevator is committed to nurturing future engineering talents through the HKIE Scheme “A” Graduate Training in Hong Kong to move people and move beyond.

More about TK Elevator

TK Elevator is a global leader in vertical transportation and urban mobility. We provide engineering services that keep the world moving, from design to installation and maintenance on any brand of elevators, escalators, walkways, lifts, passenger boarding bridges, stairlifts, platform lifts and home elevators – any place and any time. With our digital solutions like AGILE and the Internet of Things (IoT) platform, MAX, there are no longer any limits to urban mobility. TK Elevator became independent following its separation from the thyssenkrupp group in 2020. The company achieved sales of around €9 billion in the fiscal year 2022/2023. With around 50,000 employees, 25,000 service technicians and over 1,000 support centres globally, we are moved by what moves people. TKE – Move Beyond.