"Work safely aloft" is the motto of this height access problem specialist, more, users, planners and developers of real estate know the economical value of rubber-crawler-mounted aerial access platforms, which, moreover, facilitate more personal and building safety. This contribution clarifies some decisions which potential users need to think about before doing a job.

Aerial Access Platform
Architecture is becoming more extravagant these days. As regards height, there is almost no limit, e.g., the Swiss Re Tower in London, one of the tallest buildings in the world, to which one can think. A height of 180m, 22000 m2 of glass which consists of 5146 façade pieces, 40 floors, atria which reach up over 6 floors, are just some of main features of this famous building. On top of these is the extravagant architecture, not dissimilar to a sugar loaf in shape. In these surroundings necessary maintenance, cleaning and general applications cannot be achieved with a ladder.

Aesthetics. . .

Moreover, not only outside, but also inside today's modern buildings is also extravagant, with stairs, projections, plants and lighting to consider. As well as glass and facade cleaning, there are more jobs to do at height. The building manager is therefore absolutely interested in making sure the structure is most in good condition with as little trouble as possible when doing the necessary work. On the other hand, the safety of the responsible people is very important. This means they must be able to solve these problems of working at height by being given the right tools. This is where aerial access platforms come in.

. . .and focus on profitability

Hermann Leusder
In the vast majority of cases the architect, due to aesthetics or economics, does not cater for height access technology in his building plans. In fact access platforms, for example, have an enormous effect on the structural engineering. Many architectural "eye catcher" were for this reason not practical. Many standard solutions cannot fulfill all the applications, as they travel either horizontally or vertically and do not reach all the necessary points. Additionally, they sometimes disturb the aesthetics. Nevertheless the work has to be done. Ladders can be used up to a height of 4 m, but this does not cover the whole spectrum of necessary work, nor are they completely safe. Scaffolding is also used a lot, but that is very expensive and inflexible and is time consuming. The use of abseilers has to be authorised by the health and safety authorities executive. Such authority is only granted in Germany and Europe when there is no other possible method for height access available. Abseilers are used more worldwide than here in Europe. The biggest disadvantage of this supposed solution is that the abseilers can only use one arm to do the work, also that they have no specific skills in e.g. cleaning, painting, roof repairs, inspection fire (smoke alarms, water sprinklers and so on.

In order to work safely at height, only access platforms can be used. "This is where our rubber-crawler-mounted LEO series is particularly strong" explains Hermann Leusder, technical manager of Teupen Maschinenbau GmbH, Gronau, Germany. "No situation is too complex, no space too small, nor floor too sensitive for our machine technology. Inside as well as outside this series shows its strength."

Safe design of equipment

Architecture has changed dramatically in the last few years. This greatly affects the interiors of prestige buildings, which present themselves extremely extravagantly to the public. When working with access platforms, it must be fundamentally guaranteed that on one hand the building is cared for and on the other the operator is completely safe. The operator has his safety in his own hands in as much as he should wear a safety helmet and safety harness, plus any other required by regulations. The standard of the machine is constructed by the manufacturer.

There are many different types of aerial platforms, amongst others, scissor lifts, trailer-mounted, truck-mounted, self-propelled and rubber-crawler-mounted. The latter available from 12-50 m and can be used indoors. Worldwide there are approximately ten manufacturers of rubber-crawler-mounted machines. In sorting the wheat from, however, from the chaff, it must be determined what technology the machine includes, as to what the machine can do; easy to operate? What about weight on sensitive floors? Spare parts available? After-Sales-Service and so on? "Further, national CE marks and international EN 280 norms have to be taken into account in building such machines" Hermann Leusder made clear. The "solution expert" for complicated applications at height, Teupen Maschinenbau builds machines to all current national and international standards.

New Generation Access Platforms

Various choice criteria

"High working height, light, a big outreach, as well as a dynamic, problem free telescoping out. That is what the ideal new generation access platforms looks like. In order to cover all these points", the technical manager said, "many construction criteria had to be taken into account." The total weight of the machine plays an important role. The lighter the machine is in the telescoping boom and the basket, the higher the boom can telescope out, therefore giving a longer outreach and a more manoeuvrable basket. Teupen is able to achieve this by using very light metals, either reinforced aluminium, or special aluminium alloys, such as are used in the aircraft industry, for example. In this way a lot of weight is saved, but a higher level of safety achieved.

The technical manager reported that the special alloy used by Teupen is called Aluminium Foam Sandwich (A.F.S.). The metal is formed by pressing a specially foamed granulate between two pressed aluminium plates. This aluminium sandwich concept gives a light, stiff structure, but which is very strong and safe.

An access platform built of steel with a wheeled chassis is a big, heavy machine, which takes up a lot space and creates enormous ground pressure. In order to avoid damage, the weight of the light crawler-mounted machine made of aluminium and steel is distributed over the greater area of the crawler on the ground/floor, than wheels. This enables all sensitive ground/floors, such as marble, carpet tiles, sewage pipes, lawns and so on to be negotiated without any problem due to the much lower point loadings.

Source of failure: human error

Access Platform Solutions
Human error is the main reason for accidents which happen during setting up an access platform to work. This statement becomes all the more meaningful where the operator has very restricted space in which to manoeuvre and is not as careful as he should be. This failure source must be stopped. This can only be achieved by electronic control of all machine criteria. The light aluminium and steel construction and modest sizes are technical advantages in their own right. Likewise, also relevant is that the outrigging system electronically controls the outrigger feet directly and not at the cylinder, thereby enabling the machine to be fully set up and outrigged without any danger. The access platform will stand stable and will be unable to tip over and cause any damage to people, building, etc.

At the actual work site the sophisticated Teupen control technology plays an important role. The now standard and for access platforms developed "Fuzzy Logic" on only Teupen machines, works smoothly and reliably in operating these models safely in all conditions. In addition, this modern generation of access platforms including articulated booms enable the operator to reach every corner and up and over overhangs. Indeed, the more flexible is the boom, the better one can reach one's workface at height. A further safety aspect is that the telescoping sections operate via a roller system, enabling a self-centralising both out and in of the boom for safety, sureness and smoothness.

The operator's basket must also be considered from a safety aspect. The basket and jib operate like a human hand and wrist for greater flexibility in order to reach every nook and cranny and this must be achieved without any dangerous contortions. The operator can concentrate on his work and feel safe and secure. Basically, the more of the above-mentioned safety features there are on an access platform the more unlikely it is to be able to damage during operation. It is human nature to ignore danger in attempting to attain one's goal. Thus, conversely, the more impossible it is to cause problems during operation because of the increased technology, safety features, safety increases.


Usually accidents with aerial access platforms, which can sometimes be fatal, are caused by human beings. The technology is safe. With modern platforms the technology is so sophisticated that the operator cannot by-pass any controls, or shot-circuit the system, so to speak, the machines electronics set the standard. Should anything go wrong during operation, or a breakdown occurs the operator must be able to return safely to terra firma. In the event of breakdown, it is important that safety valves prevent outrigger cylinders or other assembly groups sticking, causing the machine to collapse. "The sum total of all the components results in a well-engineered height access technology" concludes Hermann Leusder, "And provides for working safely aloft."