Staying in Line Around Roundabout

SUPER 1803-2 builds roundabout with precision and reliability.

In road construction, building roundabouts is a considerable challenge that calls for the very best equipment. However, with the right paver technology and site logistics, jobs of this kind can be completed without difficulty, even when tight radii are required. Proof positive was supplied by contractor Vogel-Bau when they paved wearing course for a roundabout in Achern, southern Germany. Using the wheeled VÖGELE SUPER 1803-2, the paving crew went round a perfect 360° bend!

Roundabouts are an integral part of the road infrastructure in many countries. Even in Germany, where they had become a thing of the past, city planners increasingly are reviving these round, “traffic light-free” junctions, not least because they can reduce traffic congestions and accidents. In Achern, a junction had to be converted to a roundabout. For the job, contractor Vogel-Bau GmbH, based in the town of Lahr in Germany’s Black Forest, was able to take full advantage of the powerful SUPER 1803-2.

SUPER 1803-2 puts power on the road

Traction is a decisive factor at roundabout construction sites. Precision work is only possible if the paver can exploit its engine power to the fullest and the wheels don’t spin. This is where the SUPER 1803-2 boasts a number of features ensuring excellent marks for traction. Among them is an optimal, low centre of gravity along with the best possible weight distribution. The large contact area of the powered rear wheels and front wheels with wide solid rubber tyres, too, add to superior grip.

Traction Management System for optimal distribution of tractive power

SUPER 1803-2, like all wheeled VÖGELE pavers, comes with powered wheels for which separate drive and control are provided. For the paver, the drive versions 6x4 (standard) and 6x6 (option) are available. Thanks to the four-wheel or all-wheel drive, maximum tractive effort is ensured at all times. The core of the paver’s intelligent drive concept is an electronic Traction Management System (TM) specially tailored to the paver’s requirements. The Traction Management, in conjunction with an electronic differential pawl, provides for an optimal distribution of the tractive power to the paver’s powered wheels. As a function of wheel position, the TM regulates the power output of the separate drives in such a way that the pave speed, once selected, is maintained constant when turning a radius – a great benefit for roundabout construction.

Statically defined undercarriage provides for permanent ground contact

Due to the wheeled VÖGELE pavers’ statically defined undercarriage with 3-point support, a proven VÖGELE feature since long, permanent ground contact of all wheels is guaranteed. Integral parts of the statically defined undercarriage are the rigidly mounted rear wheels and the oscillating front wheels. Irregularities in the base are compensated in the transverse direction by the oscillating axle and in the longitudinal direction by oscillating bogies. This is the optimal precondition for the paver’s wheels to maintain permanent contact with the ground in every job site situation. When building the roundabout in Achern, this design feature also played its part in smooth paving.

A turning radius (outside) of just 6.5m

On the job site of contractor Vogel-Bau, the SUPER 1803-2’s excellent manoeuvrability also was a great benefit. With its small turning radius of just 6.5m (outside), the paver manoeuvres and steers easily on small construction sites – including roundabouts. The Vogel-Bau crew was duly impressed not only with the machine’s manoeuvrability and tractive effort, but also with the overall performance of the SUPER 1803-2 delivering 129kW. It took them no time at all to pave 4cm asphalt wearing course on the circulating carriageway of 1,200m² and on the turn-offs to the connecting roads.

Accurate screed control thanks to ErgoPlus®

The wheeled SUPER 1803-2 easily got to grips with the tight radius. For the AB 500-2 Extending Screed in TP1 version, the single-tube adjusting mechanism provided high stability during screed width control.

A tricky construction job like building a roundabout also underlines the advantages of the user-friendly ErgoPlus® concept for paver operation. The pave width changes constantly at the interface between the circulating carriageway and the connecting roads – as it typically does for many other urban construction sites as well. In these areas, convenient operation of the screed with ErgoPlus® pays off in more ways than one. “Operating is super easy,” says screed operator Reinhard Beck of Vogel-Bau. “The large push-buttons on the screed console are great. You always press the right button without having to take your eyes off the outer edge of the road.” The AB 500-2 Extending Screed varies precisely between the required pave widths, thereby contributing to the high quality paving that VÖGELE users appreciate so much.

Maximum flexibility for the paver operator

Another aspect was important to machine operator Michael Kornmeier. During the job in Achern, he repeatedly had to change sides on the operator’s stand of the SUPER 1803-2. At times he had to follow the inside edge of the centre island to the left, and at other times the kerbstones to the right of the paver. With ErgoPlus®, changing sides is easy, and that was an important advantage for Michael Kornmeier: “The operator console slides smoothly across the entire width of the platform and can be quickly locked in place on the other side.” As a result, the driver is always in the best ergonomic position and can safely operate the paver in all situations.

Vogel-Bau satisfied on all counts

The job site in Achern showed to the Vogel-Bau paving crew that the SUPER 1803-2 in their equipment pool was exactly the right paver for medium-scale jobs calling for high laydown rates and superior manoeuvrability at the same time. Peter Kreusch, Vogel-Bau foreman, confirmed: “This wheeled paver makes our work very easy. The job in Achern proved that beyond a doubt.” For the road construction professional, the wheeled VÖGELE paver even is: “the best machine I've worked with in 25 years of paving experience. ErgoPlus® above all makes operation very easy and reliable.” The customer also was very happy with the quality of the job and the fast work of both the crew and the machine.

An Overview of the Advantages of Roundabouts

  • Compared with signal systems and priority junctions, roundabouts increase traffic safety as they slow down vehicles on entry. Motorists have a better view of the traffic situation.
  • On roundabouts, there are much fewer conflict points. If accidents nonetheless occurOn roundabouts, there are much fewer conflict points. If accidents nonetheless occur, they tend to be less serious – involving only minor car body damage in the majority of cases.
  • Roundabouts improve the flow of traffic due to shorter waiting times compared to traffic light junctions. The volume of traffic is handled very efficiently with a minimum of delay or congestion.
  • Roundabouts are good for the environment. Less motor vehicle exhaust fumes are emitted, thus involving less air pollution.
  • More than four entry arms can easily be integrated into roundabouts. Large vehicles have no problems negotiating the roundabout from any direction.
  • There is no need for signalling systems which eliminates maintenance costs. From this point of view, roundabouts are particularly economical.

Roundabouts in Europe: The UK is the Cradle

Proud of their perfect paving result: With their VÖGELE paver, the crew placed wearing course of highest evenness.

In many European countries, roundabouts are an integral part of the road infrastructure. They are particularly common in the UK, France, Spain and Switzerland. And no wonder, with their many advantages over junctions (see above). Traffic experts agree that the UK was not only the cradle of football, but also of the roundabout. Each day, Britons drive up to 60,000 cars through their large three-laned roundabouts.

In Germany, this method of arranging traffic junctions was neglected for decades. From the 1960s, town planners gave preference to signalling systems and hence traffic lights were used to divide up the intersecting flows of traffic. It is only in the last 15 years or so that roundabouts have made a comeback. Town planners are now increasingly resurrecting these “traffic light-free” junctions. With a grand total of 20,000 "ronds-points", France is the home of over half of all roundabouts in the world. There is hardly a road into a town that does not have a roundabout – even if there isn't a single turn-off. This is because town planners are using the fact that motorists have to slow down before entering a roundabout to ensure that they drive into residential areas at a reduced speed. Perhaps the most famous “rond-point” in the country is the one around the Arc de Triomphe in Paris.