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Theme: lifts and escalators

After a prolonged period of stalled similarity, the vertical transportation industry is finally in a state of flux, as leading companies such as Otis, Kone and ThyssenKrupp seek to surpass each other with radical new ideas and concepts to suit and drive the buildings of tomorrow Bureaucratic red tape is stifling inventive design in all aspects of the European building industry, especially in the vertical transportation (VT) area, where every elevator looks very similar to the next - rather like the automotive industry, where most brands are indistinguishable from each other and, design-wise, are extremely dull and uninspired. There are, of course, notable exceptions in both the automobile and building industries. These usually occur where signature design houses or architects want to create a statement and bring the elevator in harmony with the environment, as for example with Kone's installation at the Richard Rogers-designed Lloyd's Registry of Shipping building in London.

In these circumstances, building designers, owners and lift manufacturers welcome new concepts of lift engineering with open arms.

But with so little imagination frequently shown outside this top end of the market, it is refreshing that elevator companies are now introducing designs and products that are of a good design, making the VT systems safer, user friendly, and using less building volume. These are not limited to the multinational companies, which have mind-blowing research and developments budgets, but are also coming from the smaller national and local companies, which are developing and testing ideas and concepts that enable them to fulfil a vital role in their market sector.

The VT industry is not just confined to providing lift and escalator systems for mediocre international buildings that could be in London, Berlin, Madrid, New York, Singapore or Tokyo, or super-fast elevators in super-tall buildings, which get volumes of media coverage. A high proportion (more than 80 per cent) of all the VT systems) installed go in buildings with fewer than 30 floors, and provide universal access to public or private premises. If we take an imaginary journey through a modern building we can see these new products in everyday use.

Radical rethinking The world's largest lift company, Otis, has recently been thinking radically about what, up to now, had been considered traditional projects whose designs haven't altered for decades. To break into the machineroomless (MRL) markets, the boffins at Otis launched their second-generation lift machine several years ago, referred to as GEN2. This turned the concept of lift drives upside down with its radically different and effi cient design of drive machines, using highly flexible belt drives. The GEN2 machine, although very compact, can provide the motive force to drive the most commonly available lift sizes and speeds.

Otis has also looked at the escalator (which, incidentally, was Otis' trade name - until the word was deemed to be generic, rather like 'Hoover' and vacuum cleaners).

These look the same worldwide, despite manufacturers' attempts to change handrail profi les, balustrade materials, lighting and truss cladding. It would take an expert to differentiate between the manufacturers just by visual inspection.

The next step Otis' approach was to look at all aspects of design, and especially at the potential hazards to users, although the strict European Code EN115 already ensures a very high degree of safety. With the launch of The NextStep escalator, Otis has taken a radical design approach, especially in the area of step design, as this is an area of possible entrapment. Its design eliminates the gap between the escalator step and the side of the escalator, because the step is now a combined single module. Not only has the step been totally redesigned, but additional safety improvements are also incorporated in the design of the comb plates and handrail entry junctions, and there is an overall space saving of 15 per cent on previous designs.

This is significant, with rentable office-space values rising each quarter, making any space saving obviously worthwhile.

Sculptural approach For many people with disabilities, escalators are not a feasible option. They need a lift or a ramp. Most disabled lifts are of a standard design, using conventional drives, and the lift cars are box designs with limited ranges of finishes and information systems.

Therefore it is refreshing that Paul Britton (technical director of Doppler), together with Arup, looked at the overall design of disabled-access lifts and ignored the conventional industrial-looking access lifts.

They took a clean sheet of paper and looked at every aspect of the design mechanically, electrically and architecturally. The finished lift is not only extremely functional but is also a piece of moving sculpture. It moves in a space that blends into the building without the need for structural steel members, large expanses of sheet steel or industrial methods of fixing components together.

In coming up with the correct design of lift, the words 'sculpture' and 'architectural designs' dominated the process. Therefore the choice of materials, components and fabrication was blended into the finished lift. The stainless steel tubular hydraulic rams and guides provide the smooth vertical lines. Architectural welding, LED illumination, a glass lift-car floor and secret fi xings all blend effortlessly into a functional lift, which is also a unique piece of moving sculpture.

Better control The multinational lift companies have made signifi cant advances in lift-control design since the days of the lift operator over a century ago, but even today, and even with the most intelligent systems available, lift controls are unable to determine how many people are waiting in a lobby. Traditional lift-control systems only know that a call has been registered in a lobby or in the lift car. They do not know how many people are behind the call (it could be one person or 20) or where they want to go. They could all be going to the same floor, or to 20 different fl oors. Ideally the lift control would assign a lift which had space, but conventionally what arrives is just the nearest lift, or a lift travelling in the same direction. Therefore lifts may arrive to answer a call with space for say three people, yet 15 may be waiting and will have to re-register the lobby call again - not a very satisfactory arrangement.

That is, up until now. Schindler Top Range Center has developed its Miconic 10 ID control system. Not only has Schindler integrated its successful Hall Call Destination (Miconic 10) control system, it has also taken passenger movement into a new dimension with personalised passenger applications that satisfy individual passenger requirements and provide optimal lift performance based upon their needs. This individualisation provides improved lift traffic capacity, travelling time and security.

Making space In the modern building, the needs of the handicapped must be considered, but also those of VIPs (very important people) and CIPs (commercially important people). All these groups need more space in the lift cars, for reasons of physical space requirements, individual security or confidentiality.

With the Miconic 10 ID system, this is now achievable by the use of smart cards, PIN codes, key rings, watches or combinations of these methods of individual identification.

This means the occupants of the building or visitors are security checked prior to the journey, and the call station assigns the right lift car based on the intending passenger's needs and security rights.

Doubling up Not to be outdone in the radical thinking process, ThyssenKrupp's research and development division has decided that it would be a good idea to have multiple lifts (the Twin System) in the same shaft.

This concept has been used before with the Double Deck lift, in which two lift cars are fi xed together and travel up and down together. The problems with this system is that, although the Double Deck lifts were very efficient in terms of core volume used (a saving of 30 per cent is considered to be typical), the lift drive and control systems had to cope with large dynamic loads. This made the costs per unit unacceptably high.

ThyssenKrupp was mindful of these concerns, and decided instead to install multiple lifts in the same lift shaft. By using sophisticated lift-traffi c algorithms, it is possible to ensure that the safety spacing of lifts is maintained so that you can not only have both lifts travelling in the same direction, but also have them moving away from each other or on a converging path.

With its Twin System, ThyssenKrupp is also using its Hall Call Destination control system. This allows the individual lifts to be kept apart, because the passengers' destinations are determined and stored in the lift-control memory. This radical design is in daily operation and is not just a concept design. Perhaps one day we will see three or more lifts in the same shaft.

Rethinking the door Smaller companies that manufacture lift components have also been innovating, mainly in the generic areas of design. It is an established fact that approximately 80 per cent of recorded worldwide lift breakdowns are related to lift doors and their associated sub-systems. For the visitor or residents of a building, the lift landing doors give the fi rst impression. Global Lift Equipment is now offering a new range of bespoke lift-door drives. These can work with designer fi nishes at the commercial end of the market, and with the very special explosion-proof designs that petrochemical applications require. Within the Global range of specialist doors, there are both framed and frameless designs. The latter are provided with reinforced top tacks and larger-diameter door rollers due to the weight of the individual door panes, and carry a fire-rating certificate.

Global has also launched the first ever variable-voltage variable-frequency (VVVF) circular design of lift door, available in stainless steel or glass. This type of door allows the lift designer to have not only rectangular lift cars but also designs that incorporate circular doors and lift cars.

Safe as planes Users of lifts take it for granted that lift installation is one of the safest methods of transport available worldwide. Only air travel is safer on the miles travelled ratio, making the lift the safest method of transportation available without the need of the user to take a test prior to using it.

However, design developments in lift shafts and motor rooms are making journeys even safer, very reliable and more effi cient. They do this by using intelligent controllers that are being marketed to the independent sector of the lift industry.

LiftStore has recently launched a new concept in lift controllers with its ETHOS design of controller. This is a 16-bit or 32-bit internal CPU with a processing capability of 30 million instructions per second. Since the reliability of lift systems is so important, and any poorly designed control systems will without doubt lead to failures, the LiftStore ETHOS control system has undergone an enormous amount of development. The resultant design is an extremely reliable control system for groups of up to four lift cars, which can be used on new and modernisation projects.

Evacuation strategies What is the future going to be for lifts in the next generation of buildings? The key word is evacuation. As new buildings become taller, wider and deeper, there is not just a need to get all the occupants including those with disabilities into the building during peak periods. There is also a real and moral need to get people out quickly and safely in an emergency situation. These conditions are classifi ed as 'imminent catastrophic events' (ICE). During an ICE, lifts in future buildings will have to be used to assist in the total or partial evacuation of the building, instead of reliance being placed solely on the traditional emergency staircases.

Arup R&D has developed a lift-analysis simulation program that considers not only how the lift groups move the waiting passengers from the upper and lower levels of the building, but also the waiting time in lobbies and the fl ow rates in the stairways and corridors. The program can determine the number of lifts, speeds, capacities and design variables such as acceleration and rates of changes in acceleration together with the number of stairways and flow rates of people on the stairs. This design platform allows the designer not only to see the effects of a free-flowing design in the lift shafts and stairways; it can also allow for various ICE scenarios where there may not be 100 per cent lift capacity, or where an emergency staircase may be blocked or the flow rate of people reduced, due to the presence of less mobile people in the stairwells.

It is therefore not enough just to design, advise and specify the correct size, speed and drive of lifts to get the occupants into the building within international guidelines for waiting intervals, handling capacities and percentages of people transported in five minutes. Now the question being asked is how long it will take to evacuate the building during an ICE.

The future of lift engineering is exciting.

Multinational companies are developing new and inventive ideas by revisiting conventional thinking. The smaller design and component companies are not content with traditional tunnel vision, and are thinking how to design lifts and sub-system components that are architecturally acceptable. This should suit the client who does not want a run-of-themill lift installation but, like many building owners, has a fear of non-generic lift equipment. As a result, this sector of the lift market is buoyant, with specialist component companies offering architectural lift glass doors and intelligent lift-control systems to provide the much-needed flexibility in design of lift components.

This all means that new or modernised lift design need not be restricted to traditional square boxes from standard catalogues using mediocre manufactured systems and industrially designed components. The only limitations to lift-system design today are within your imagination.

Roger Howkins is a vertical transportation specialist with Arup

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