MOST able-bodied people are willing to walk for up to 500m to reach a metro or railway station, but as the distance increases people start to use other means to reach the station, or forsake rail completely and choose other modes.
ThyssenKrupp believes it has developed a system to extend the reach of rail without the need to build additional stations or costly extensions to the network. It is called Accel - a high-speed moving walkway capable of carrying 7300 passengers/h/direction in a permanent flow at speeds of 7.2km/h, or above 10km/h for people who decide to continue walking while on the belt, which is around double the average walking speed.
According to ThyssenKrupp, passengers using Accel will take only 2min 20s to cover a distance of 270m, compared with around 5 minutes walking. Accel can transport 7300 people/h which the company says is similar to the capacity of a typical fully-automated peoplemover.
ThyssenKrupp believes Accel will be cost-effective to introduce as it negates the need for major infrastructure or civil works. The manufacturer says it is extremely simple to use as it operates continuously thereby eliminating the waiting times associated with peoplemovers or bus links and it does not require any entry barriers.
Accel will also make it possible to reduce the time taken to interchange between different lines on a metro while accelerating passenger flow. It should be particularly attractive where the distance between a metro station and a mainline station, or between a station and an airport terminal, is too far to walk but not long enough to justify a peoplemover.
When using Accel, passengers enter at a normal walking speed of 0.65m/s, accelerate smoothly up to 2m/s or 7.2km/h, and then decelerate back to normal walking speed before leaving the system. Passengers enter and exit Accel at the same speed as they would using a conventional moving walkway.
Accel is composed of a band of pallets, which have a similar appearance to a standard moving walkway. The band is built using an overlapping pallet concept which expands the original size of each pallet by a factor of three.
Each aluminium pallet consists of two parts which at the start of the walkway, are laid closely one over the other. As the speed increases, they push apart, before coming together again near the end to ensure smooth speed changes.
Every pallet is equipped with its own magnet propelled by linear induction motors installed in fixed positions. Although the pallet band and the handrail are separate they operate precisely in sync with sensors constantly focusing on the position of the individual grips and pallets, to ensure that passengers always feel that they are both moving at the same speed.
The low-vibration and low-maintenance linear motors have been developed from the Transrapid maglev train. The motors and encoders are synchronised by a control system, but should a motor fail, a mechanical safety chain engages and pulls the pallet via a dragger to maintain operation.
Although it looks like an ordinary moving walkway, the band forms a circuit and the pallets return via the opposite lane rather the beneath the walkway. The bends are invisible to passengers as they are located below the floor surface, which is how Accel achieves a construction depth of only 1m - similar to conventional walkways.
Accel was developed by the ThyssenKrupp Elevator R&D Centre in Gijon, Spain, with the support of the ThyssenKrupp Transrapid project and suppliers such as ProDrive, Technotion and Bechhoff. Although there have been previous attempts to establish variable-speed moving walkways, ThyssenKrupp claims that none of them have operated trouble-free except for its own TurboTrack system at Toronto Pearson International Airport, which uses a previous generation of technology.
ThyssenKrupp is confident that it has overcome the problems associated with previous designs of variable-speed moving walkways and believes Accel can make a valuable contribution to improving urban mobility.