D e s c r i p t i o n d r i v e & co n t r o l s y s t e m
The drive system has been specially designed and developed by Siemens. The complete drive and control system is built in a purpose built and air-conditioned control booth. Special software allows automatic operation, including loading and unloading features.
A Siemens S7 400 PLC digitally controls the fully automatic drive and loading system. This system is connected to a Siemens Simatic PC with touch screen colour display, which is equipped with a modem to connect to the Internet and E-mail for online backup service. The software is based on Microsoft Win CC and especially designed and developed to support the whole Giant Wheel in every technical aspect. The control system is supplied with a power indicator, a default indicator, and a logbook. The total control system is already suitable for a central maintenance information system.
The Giant Wheel is rotated by four frequency controlled self-cooling Siemens AC Brake motors which drive the wheel through SEW industrial gearboxes. The chosen drive system is a friction drive compromising four individual drive-units using four rubber wheels to transfer the force to the wheel. This drive set-up ensures synchronization between the drive units and ensures redundancy in the drive system. In order to attain the appropriate friction of this system, the outer rim of the wheel will be coated with an all-weather friction material.
The power supply needed for the drive system is 380/415 V, 50/60 Hz. The control system has an evacuation mode with battery back-up system, in case of power failure. This battery back-up ensures that the wheel can be safely unloaded by operating the 24 volt DC negative brakes and using gravity. Passengers can get off safely and comfortably, and will not have to wait until the power is back on. In the extreme case of a failure of the 24 volt back-up system the brakes can be manually lifted with the same effect. This is practised during operator training.