Setra S 531 DT
07.07.2017 - 01:00

German version

Setra S 531 DT

  • Safety: world premiere for Active Brake Assist 4, Sideguard Assist in the bus and coach segment
  • Efficiency: outstanding aerodynamics lower fuel consumption
  • Variability: the new Setra is a bus to meet all needs
  • Comfort: bright interior, convenient stairs, innovative washroom
  • The Setra double-decker bus is "heaven-scent"
  • Design: modern and surprisingly distinct appearance

Maximum efficiency and variability, supreme comfort and the ultimate in safety: the new Setra S 531 DT double-decker bus of the TopClass 500 sets new standards in its class. With superlative aerodynamics, this impressive touring coach is all set to establish new fuel efficiency records in its segment. With its flexible lower deck, it covers the entire scope of applications in touring and regular services. The interior boasts an impressive standard of comfort. Finally, the use of Active Brake Assist 4 and Sideguard Assist on board the new double-decker bus will mark the world premiere for these assistance systems in the bus and coach segment. These systems further enhance the already high standard of safety. All this is cloaked in a fascinating design with its own distinct stamp.

Safety: world premiere for Active Brake Assist 4, Sideguard Assist in the bus and coach segment

The very highest safety as standard – courtesy of Daimler Group technology. The premium brand's new double-decker comes as standard with long-life LED headlamps which are kind on the eyes. The emergency braking system Active Brake Assist 4 (ABA 4) is being introduced in the bus and coach sector for the first time ever on board the S 531 DT. In addition to the previously available functions – maximum full-stop braking in response to stationary objects and obstacles moving ahead of the vehicle – it now also incorporates pedestrian detection with automatic braking response. Another world premiere in the bus and coach segment is the use of Sideguard Assist on board the new double decker. This employs radar sensors to monitor the lane to the right of the bus along the vehicle's entire length. When turning off and cornering, it warns the driver of pedestrians, cyclists and stationary obstacles in the turning path. Outside of built-up areas, it additionally serves as a lane-changing assistant.

Efficiency: outstanding aerodynamics lower fuel consumption

The new double-decker bus is tailored for optimum aerodynamics from front to rear. At the front, windscreens with pronounced curvature and large edge radii allow the air to flow around the vehicle, while at the rear recesses and airflow breakaway edges guide the airflow in a controlled manner. The development engineers have attended to the most minute details: the windscreen wiper on the upper deck is vertical in its rest position, for example – a feature adopted from motorsport. These measures result in a drag coefficient of Cd = 0.35 - a new benchmark for this segment. The aerodynamics provide the basis for record-breaking fuel consumption, which drops by around seven to ten percent compared to the predecessor model, according to the type of use. Depending on the mileage covered, this adds up to savings of several thousand litres of fuel annually.

Variability: the new Setra is a bus to meet all needs

Holiday travels, long-distance regular services, stylish bistro buses, inter-city lines – the new Setra covers all conceivable types of use for a bus on this scale. The variable lower deck provides the basis for this versatility, together with the scope for individual appointments and seating which is typical of the brand. Thanks to a completely new construction, the platform on the ground floor on the right as seen in the direction of travel can be omitted if the customer so desires. This results in new options: wheelchair bays, installations for bistro buses, a demountable platform with pram area for inter-city lines or, with platform, the classic seating for touring purposes. The available diversity is also manifest in the cockpit: customers can choose between the elegantly functional cockpit from the Setra ComfortClass 500 and the luxurious cockpit from the TopClass 500.

Comfort: bright interior, convenient stairs, innovative washroom

With a bright interior, with plenty of light and a modern design, the interior of the new Setra makes a spacious impression. The stairs connecting the lower and upper deck catch the eye in particular. Glazed on the outside, they feature panelling consisting of translucent acrylic plastic on the inside. Evenly spaced two-tone steps with individual lighting, landings and continuous handrails give passengers a sense of security when going up and down the stairs. The washroom in a totally new design is also worthy of note. Its installations are arranged diagonally, making maximum use of the available space. The gleaming white upper areas of the furnishings and the pleasant LED lighting are reminiscent of a modern bathroom.

The Setra double-decker bus is "heaven-scent"

An optional fragrance dispensing system takes the already pleasant climate on board the new Setra to new heights. When the ignition is turned on and door one is opened, or when a door is left open, a fragrance generator automatically dispenses a discreet and unobtrusive yet highly pleasing scent. In this way, a fresh yet unobtrusive aura welcomes guests on board and encourages them to feel at their ease. The main components have been taken from the Mercedes-Benz S-Class. There are six fragrances to choose from, ranging from fresh and sporty to a heavier scent that reminds one of leather.

Design: modern and surprisingly distinct appearance

The new double-decker bus belongs to the Setra TopClass 500. Within the 500 model series, it is nevertheless in a class of its own, on account of its broad spectrum of applications and its diverse scope of equipment and variants. This is documented by its modern and distinct appearance. The Setra's face with its dark front panel and silver brand lettering clearly originates from the TopClass 500. As a new feature, the two windscreens are seamlessly joined together and structured by an aluminium bar. On the side wall, the designers have adapted the brand's hallmark "La Linea" aluminium strip, which now extends horizontally along the edge of the roof. The extensive glazing is highlighted by a counter-sweep at the level of the rear stairs, which adds a dynamic touch and features an aluminium surround. The panelling of the upper deck now appears to hover like an island on the glass. Underneath, an aluminium badge above the front wheel arch provides a break in the waistrail on the lower deck. Side fins with airflow breakaway edges and the tail lights of the 500 model series frame the rear end. On the new double-decker bus the two vent grilles for the engine have been joined together. Above these, the black grille of the integrated TopAir air conditioning system makes its mark. The chrome-plated badge featuring the brand lettering from the TopClass 500 catches the eye under the rear window – a perfect finishing touch for a spectacular bus.

A bus to meet all needs: high flexibility for long-distance regular services and touring alike, innovative design and a distinct character
  • One for all: the new double-decker bus covers all applications
  • Lower deck: completely new construction and substructure
  • New: member of the TopClass 500 – design in a class of its own
  • An aluminium bar joins the new windscreens
  • The side wall boasts a dynamic and elegant appearance
  • The newly designed rear end makes its mark with its vent grilles.

Maximum comfort in long-distance touring, exclusive trips in a bistro bus, pronounced individuality as a tour bus, practicality on long-distance scheduled services, high functionality on rural services during the week and on excursions – diverse requirements apply to double-decker buses, as they cover a vast spectrum of different usages. The new S 531 DT is a bus to meet all needs, its innovative design giving rise to an astoundingly diverse range of variants that enables a single model to cover the entire spectrum of potential applications. Its cutting-edge design sets it apart. It is unmistakably an elegant and powerful Setra, yet with a distinct character of its own.

The ideal size for double-decker buses in touring use

Measuring around 14 m in length, its predecessor defined the ideal size for double-decker buses in touring use: practical manoeuvrability, standard seating for 83 passengers and sufficient space remaining for comfort features such as a washroom and toilet compartment and a kitchenette on the lower deck. Plus adequate space for suitcases and bags in the luggage compartment over the drive unit and additional reserves of space in the underfloor stowage compartments. The tallest Setra has already demonstrated great flexibility with a choice of stairs in the classic position on the left-hand side or the long-distance variant near to the front entrance on the right-hand side.

It was the measure of all things in its class during its long and successful career spanning 15 years and a production output of some 2300 units. The new Setra adopts and further develops the established strengths while adding new assets into the bargain.

One for all: the new double-decker bus covers all applications

The flexibly configured lower deck of the new Setra S 531 DT enables it to be tailored individually to the most diverse tasks.

One for all: comfortable touring coach with high standard of equipment and appointments, practical long-distance regular-service bus, functional seating capacity-oriented or comfort-oriented inter-city and excursion bus with full seating complement, stylish bistro bus with lounge on the lower deck, individually fitted-out tour bus or special-purpose vehicle for a diverse scope of commercial applications.

Lower deck: completely new construction and substructure

To achieve a new degree of flexibility for the double-decker bus, the engineers have developed an innovative new design for the entire construction of major assemblies and the complete substructure, in order to create space between the axles.

The main switch panel for the electrics is now located next to the entrance at the front, in service-friendly configuration on a sliding base on the pavement side. The compressed air tanks are accommodated in space-saving position below the driver's platform and in the area of the rear axles. The space, which they have vacated in the raised platform on the left, is now taken up by the fuel tanks, whose capacity has been increased from 510 to 540 l of diesel. Where necessary, the stowage compartment behind this space can accommodate an additional tank with a capacity of 170 l or even 270 l. The AdBlue tank, which still has a capacity of 40 l (optionally 49 l), remains in its position close to the engine at the rear left of the vehicle.

The spare wheel retains its standard position in the raised platform on the right of the lower deck. When companies do without this platform – e.g. for wheelchair bays in long-distance regular service use, for a pram area in inter-city use or for installations on bistro buses and special-purpose vehicles – the spare wheel is accommodated in the luggage compartment. Setra has developed a lifting device employing a block and tackle specifically to enable the driver to unload it from there without any danger.

In the interests of a tidy interior and stepless access to the washroom, the lines now run flat in the floor. The framework of the substructure, including the crossmember structure, has been adapted accordingly to ensure that the expedient ground clearance is maintained.

This means that customers can now choose the new double-decker bus with or without a platform on the right-hand side of the lower deck, with various seat configurations, wheelchair bays or pram areas, with stairs at the front on the left or right, with different door variants at the rear entrance and with various wheelchair ramps, and with or without a kitchen and washroom. The new Setra S 531 DT of the TopClass 500 is a double-decker bus made to measure.

Maximum fuel efficiency: superlative aerodynamics minimise diesel consumption
  • Good aerodynamics pay off every mile of the way
  • Windscreens with pronounced curvature and large edge radii
  • New aero windscreen wiper system with features adopted from motorsport
  • Aerodynamically efficient rear end with recesses and airflow breakaway edges
  • Aerodynamic benefit: the Setra can save around 3000 l of diesel

The new double-decker bus from Setra is a prime example of superlative aerodynamics. With a drag coefficient figure of Cd = 0.35 it sets a new benchmark in its segment. The exceptionally low wind resistance provides the basis for exceptional fuel efficiency: depending on its form of use, the Setra S 531 DT is up to ten percent more fuel-efficient than its already economical predecessor. This means that the new double-decker saves fuel and money on every mile of motorway driving, minimising emissions and saving resources in the process.

Good aerodynamics pay off every mile of the way

Images from the airflow simulation process demonstrate the new Setra's aerodynamic merits: at the front the airflow hugs the body, while at the rear the hefty touring coach does not leave any tell-tale wake behind it. Aerodynamics play a particularly important role for a heavyweight double-decker bus measuring over four metres in height, making the crucial difference in the face of the largest touring coaches' given cross-sectional area. The difference that efficient aerodynamics make pays off for bus and coach operators every mile of the way.

The double-decker's development engineers were able to draw on the extensive wind tunnel findings acquired with the Setra ComfortClass 500 and the TopClass 500. These high- and super-high-deckers boast exemplary aerodynamics and lead the touring coach field with a drag coefficient of Cd = 0.33.

Windscreens with pronounced curvature and large edge radii

The developers have pulled out all the stops for the new double-decker bus, too. The two windscreens are seamlessly joined and feature a more prominent curve. The front end of the bus has been extended by 85 mm for this purpose. The air is better able to flow around large edge radii.

Where necessary, for example on long-distance regular-service buses or inter-city buses, a destination indicator is installed behind the lower windscreen on board the new double-decker bus. Virtually no gaps remain between the body and the flush-closing doors and the driver's window. The leaf-shaped arms of the outside mirrors have also been aerodynamically optimised.

New aero windscreen wiper system with features adopted from motorsport

The aero windscreen wiper system on the double-decker bus plays a major role in reducing the vehicle's wind resistance. On the lower deck Setra employs the proven Aquablade windscreen wipers from the 500 model series. These are flat-blade wipers with integrated water guide and without disturbing stems.

The wiper for the upper windscreen came in for particular attention in designing the double-decker bus. The two-arm wiper system has been replaced by a centrally positioned one-arm wiper with flat-bar wiper blade. The vertical, aerodynamically optimised standby position for the windscreen wiper has been adopted from the field of motorsport. The wiped area corresponds to that of the previous system, whereby passengers from the second row on benefit in particular from the clear view, which is now available through the middle of the windscreen.

The vehicle's aerodynamics are also optimised by features which are not immediately apparent. The rain troughs over the doors are only unfolded when the doors are opened, for example. This means that the vehicle's outer skin is smooth when the doors are closed, thus offering no wind resistance. Another feature which is invisible on the road but nevertheless effective is the underbody cover for the front-end assembly, which prevents turbulence.

In addition to reducing wind resistance and thus fuel consumption and emissions, the extensive aerodynamic fine tuning around the Setra's front end also minimises wind noise, thereby tangibly enhancing comfort for passengers and drivers.

Aerodynamically efficient rear end with recesses and airflow breakaway edges

The Setra's newly designed rear end has also been developed with due regard to aerodynamic aspects. The roof has been provided with an airflow-optimised flue. The new corner pillars in the form of fins are recessed at the sides and feature sharp airflow breakaway edges. These two measures serve to guide the airflow in a defined manner, thereby reducing turbulence as well as soiling. The measures increase the length of the rear overhang only negligibly, by 25 mm.

The double-decker bus is furthermore lowered imperceptibly by 20 mm from a speed of 95 km/h. In addition to the comprehensive fine-tuning work on the body, in this way the developers reduce the cross-section and thus the wind resistance.

Aerodynamic benefit: the Setra can save around 3000 l of diesel

The comprehensive aerodynamic measures from the front to the rear reduce wind resistance substantially. The new double-decker's Cd figure stands at 0.35, setting the benchmark in this vehicle segment. And the Cd rating is far more than just a token value: according to Setra's experts, the reduction in wind resistance is accompanied by a drop in fuel consumption of around seven to eight percent in mixed touring use. On long-distance trips or in long-distance regular-service use, the savings are even in the two-figure percentage range.

At an annual mileage of 100 000 km, the new double-decker bus thus saves around 3000 litres more fuel than its predecessor. Savings are correspondingly higher when very high mileages apply in long-distance regular-service use. This cuts costs very noticeably, reduces emissions and saves resources.

Number one for safety: first bus worldwide to feature Active Brake Assist 4 and Sideguard Assist
  • Setra – tradition-bound to maximum safety
  • World first in the bus and coach segment: Active Brake Assist 4 brakes in response to pedestrians
  • World first in the bus and coach segment: Sideguard Assist provides warnings during cornering and turning off
  • Sideguard Assist also helps when changing lane

Buses are among the safest means of transport. Setra makes them even safer, the new Setra TopClass S 531 DT setting benchmarks with its assistance systems. The use of the Active Brake Assist 4 emergency braking system and Sideguard Assist on board the new double-decker marks the world premiere for these features in the bus and coach segment.

Setra – tradition-bound to maximum safety

ABS, ABA 4, ART, AtAs, BAS, DBL, ESP, TPMS and more besides – the scope of standard and optional equipment for the new Setra reads like an A to Z of the latest assistance and safety systems. This fits into a long tradition at Setra: in 1955 the brand was among the pioneers of independent wheel suspension on buses and coaches, in 1964 it was the first to introduce the retarder as a wear-free auxiliary brake and a few years later it championed disk brakes. Back in 1981 Setra was already optionally installing the ABS anti-lock braking system on all buses and coaches. In 1984 it became the first brand in Europe to fit ABS as standard. Introduction of xenon headlamps as standard in 2001 in the then new TopClass 400, followed in swift succession by the ESP Electronic Stability Program, adaptive cruise control, Continuous Braking Limiter, Lane Assistant and the Front Collision Guard – the highest safety standards courtesy of Daimler Group technology. Setra most recently introduced the option of integrated LED headlamps at the end of 2015.

As a result, the new double-decker buses even comes with LED headlamps as standard. The light from these headlamps is similar to daylight and is less tiring on the eyes. Their durability and their virtually undiminished luminous intensity throughout their service lives are additional benefits of relevance to safety.

Double-decker bus: with up to 83 passengers, safety is paramount

Active safety, i.e. accident prevention, is a prime concern for a double-decker bus with up to 83 passengers on board, hefty dimensions and a permissible gross weight of 26 tonnes. Should an accident nevertheless occur, driver and passengers benefit from the highest possible standard of passive safety. The previous Setra double-decker bus already benefited from a reinforced framework following its comprehensive overhaul in the autumn of 2015, thereby voluntarily meeting the requirements of the pendulum impact test in accordance with ECE-R-29. Setra furthermore provides rescue services with online rescue data sheets for all its buses and coaches.

Emergency braking system Active Brake Assist can save lives

The emergency braking system Active Brake Assist (ABA) is an outstanding assistance system. Its original version was introduced in the Setra TopClass 400 around ten years ago, since when it has benefited from ongoing further development. While the statutory advanced emergency braking system AEBS performs drastic braking to a standstill in a critical situation, the latest Active Brake Assist 3 (ABA 3) brakes the vehicle substantially earlier when stationary obstacles are encountered, applying maximum full-stop braking to bring the vehicle to a standstill. ABA 3 has been available for the Setra S 431 DT double-decker bus since 2015. Touring coaches with ABA 3 thus not only mitigate the consequences of a serious accident but are actually able to avoid such accidents, within the given physical limits. Setra installs Active Brake Assist 3 as standard if the customer orders the vehicle with the adaptive cruise control system, on whose radar system ABA 3 is based.

World first in the bus and coach segment: Active Brake Assist 4 brakes in response to pedestrians

A new chapter is now being written in the history of assistance systems: the Setra S 531 DT is the first bus in the world to feature the emergency braking system Active Brake Assist 4 with pedestrian detection – a further milestone in the development of assistance systems.

The outstanding feature of Active Brake Assist 4 is that it warns the driver of imminent collisions with moving pedestrians and simultaneously automatically initiates partial braking. It is the first system of its type worldwide to perform such functions. This enables the driver to avoid a collision by means of maximum full-stop braking or a steering manoeuvre.

Active Brake Assist 4 thus constitutes a further development of well-proven Active Brake Assist 3, incorporating an additional warning and partial braking to enhance the safety of pedestrians. Its mode of operation and displays correspond to ABA 3. Unlike when braking for moving and stationary obstacles, there is no warning cascade prior to partial braking for moving pedestrians: the acoustic and visual warnings occur at the same time as partial braking.

Long- and short-range radar systems detect pedestrians, cars and objects

The long-range radar of Active Brake Assist 4 detects vehicles and obstacles in a direct line in front of the bus up to a distance of 250 m and pedestrians up to a distance of 80 m. Motorcycles, mopeds and cyclists are detectable up to a distance in between these two ranges (160 m). The maximum opening angle is 18 degrees. The short-range radar has a range of 70 m. The wide opening angle of 120 degrees additionally enables Active Brake Assist 4 to detect vehicles and moving pedestrians at the sides of the area in front of the vehicle, whereby the range of vision is dependent on the topography, the course of the road, weather conditions and ambient influencing factors, such as pedestrians moving quickly into the traffic area or concealed pedestrians.

Active Brake Assist is able to detect moving pedestrians in virtually any traffic situation, for example if they cross the bus's lane, emerge from behind an obstacle or are moving along the vehicle's lane. Pedestrians are also detected within the range of the radar system when the vehicle turns off to the left and right. The warning and braking reactions to stationary and moving obstacles are effective across a speed range from 0 to 100 km/h, while the automatic warning and braking reactions of the pedestrian detection system apply up to a speed of 50 km/h.

The bus driver then decides on any further actions. The driver can override the system at any time as necessary, by means of a steering movement, kickdown or emergency braking, for example. If the driver does not brake firmly enough, the braking intensity of Active Brake Assist 4 takes precedence.

Multi-mode radar with improved range and performance

The basis for Active Brake Assist 4 with the additional pedestrian detection function is provided by a new generation of radar technology. This is also used in the current passenger cars and trucks from Mercedes-Benz, demonstrating the close cooperation within the group.

The advantage of a radar system is that it operates independently of the prevailing light conditions and also largely independently of weather conditions. Radar determines distances and relative speeds extremely precisely, and is also able to "see" at night and in rain and fog. Vehicles, pedestrians and objects are recognised on the basis of a radar signature. This involves analysis first and foremost of the form and reflection.

The new radar generation takes the form of electronically scanning multi-mode radar. This offers markedly improved range and performance. For the first time, the long-range radar now operates independently of the set driving level and is able to adapt continuously to changing inclination of the vehicle as a result of suspension or load statuses.

World first in the bus and coach segment: Sideguard Assist provides warning during cornering and turning off

Right turns in urban traffic are among the least pleasant tasks for drivers, as they are required to heed traffic lights and signs ahead while simultaneously observing oncoming and crossing traffic and keeping an eye on pedestrians and bike riders at the side. In addition, the traffic situation may alter in a matter of seconds and cyclists and pedestrians are not always aware that a bus driver may not be able to detect them. With this in mind, Setra is now the first bus and coach brand to offer the Sideguard Assist with pedestrian detection. Available for a year now on board Mercedes-Benz trucks, the time is ripe to introduce Sideguard Assist for buses and coaches as well.

The principle: continual information, warnings as necessary

Sideguard Assist operates in several stages: It first of all informs the driver when a relevant object is located in the warning zone. In a second stage the driver receives a warning if they initiate or continue an action and a danger of a collision arises.

If there is a moving object in the side monitoring zone the driver is provided with a visible warning. An LED in the shape of a triangle lights up at the driver's eye level in the outside mirror on the co-driver's side. The lamp draws the driver's attention intuitively towards the situation alongside the vehicle. When a danger of collision applies, a visual warning is also triggered: the LED flashes brightly several times in red. After two seconds, it remains permanently illuminated in red. A haptic warning in the form of a vibration in the driver's seat is additionally provided, as with the Lane Assistant.

A visual and haptic warning also occurs if the sensors additionally detect a stationary obstacle, such as a traffic light or a bollard, in the bus's turning curve during cornering. Collisions can be avoided in this way. The tracking pattern warning function is effective in the speed range from 0 to 36 km/h. The other functions of Sideguard Assist are available throughout the entire speed range from 0 to 100 km/h.

For the purposes of its warning cascade, Sideguard Assist also analyses actions by the driver, for example activation of the indicator on the co-driver's side or the steering movement when moving off, and the distance from a moving or movable object is assessed continuously while the truck is on the move. Sideguard Assist also warns the driver of any obstacles when they turn off without activating the indicator, for example.

The driver retains full responsibility and remains in control of the situation at all times and is able to take any course of action which appears appropriate.

Sideguard Assist also helps when changing lane

The new Sideguard Assist offers even more functions: at speeds above 36 km/h and up to the maximum permissible speed it provides the driver with warnings as an assistance system during lane changing. As such, Sideguard Assist assumes the function of a lane changing assistant. The driver is also informed of any object on the co-driver's side and a corresponding warning is output if the driver activates the indicator. This means that Sideguard Assist provides support when changing lane, for instance when overtaking a cyclist in an extra-urban setting, or when changing lane on multi-lane roads.

The radar sensors monitor the entire area on the co-driver's side

The core of Sideguard Assist is a radar sensor system with two short-range radar sensors in the wheel arch of the front axle on the co-driver's side. The side monitoring zone has a width of 3.75 m. The system is oriented so as to cover the entire length of the bus. Its range additionally covers the area two metres in front and behind the vehicle. In lane-change assist mode, the scanned area is increased to up to five metres to the rear and as much as 15 metres to the rear, in the interests of safe lane changing.

A true driver's bus: choice of two cockpits, LED headlamps, practical stowage compartments, perfectly coordinated powertrain and comfort suspension
  • New: operators can choose between two cockpits
  • New: long-life LED headlamps that are kind on the eyes as standard
  • Luggage compartment capacity slightly increased, additional stowage compartments
  • Engine and powertrain: perfectly coordinated all-Daimler engineering
  • The Setra's gentle comfort suspension

The new Setra S 531 DT is a true driver's bus. Operators can choose between the two user-friendly and comfortable cockpits from the Setra ComfortClass 500 and TopClass 500. The stowage areas – always a special consideration on double-decker buses – are readily accessible. The perfectly coordinated powertrain from a single source is powerful and economical in one. The suspension is not only safe but also particularly comfortable, thanks to full-size 80 percent tyres.

New: operators can choose between two cockpits

The broad scope covered by the new Setra S 531 DT is manifested in its cockpit: it is the first double-decker bus to offer a choice of two cockpits. And what a choice: depending on the intended form of use and the specified equipment, bus operators can choose between the standard-fit from the Setra ComfortClass 500 or the TopClass 500.

A common feature of both cockpits is their driver-friendly basic shape with all instruments and controls clearly arranged and the pendant pedals. With either cockpit, the driver has a multifunction steering wheel and precision-marked and clearly legible circular instruments at their disposal. Positioned centrally in each instance is the informative instrument cluster with its high-resolution colour display.

The control buttons are clearly arranged in blocks of four to avoid any possibility of confusion. The digital tachograph and the electronic key are located in a driver-friendly position to the left of the steering wheel. As previously, the driver operates the transmission by means of a space-saving and self-explanatory pitman arm. Both cockpits feature the Coach Media System (CMS) with a brilliant seven-inch display. The CMS incorporates the separate entertainment electronics for passenger compartment and driver's cockpit, the navigation and the telephony system in compact and clearly arranged form in a single device. Practical stowage facilities and drinks holders are installed around the instruments.

Cockpit from the ComfortClass 500: functionality and flexibility

In addition to functionality, a high degree of flexibility is another key feature of the cockpit from the ComfortClass 500. The cover over the large open stowage compartment on top of the centre console can be removed, for example, and a fixing pin and cash register can be installed in its place – an important option when the double-decker bus is deployed on regular services. The doors can also be unlocked using the electronic vehicle key.

Cockpit from the TopClass 500: exclusive design

The cockpit from the TopClass 500 represents an even higher standard. It fits even more snugly around the driver and is characterised by an exclusive design: an elegantly curved aluminium bar serves as a surround for the instrument panel, while round air vents add a dynamic touch. The cockpit cover flows harmoniously from the driver's side to the tour guide's side. The driver has diverse information to hand on the display of the Multi Function Key.

As the multifunction steering wheel and instruments, the basic aspects of operation and the control panel as well as the Coach Media System (CMS) all correspond to the TopClass 500, drivers will have no problem switching between buses with different cockpits within the same fleet and will not need any time to adjust to a new work environment. As the package, i.e. the space situation, and the operating logic are identical for all Setra touring coaches, drivers can even switch without any problems between all the vehicles.

New: long-life LED headlamps that are kind on the eyes as standard

The comparatively low seat position in conjunction with the imposing dimensions of a double-decker bus imposes high requirements on visibility. The new outside mirrors provide a better view from the cockpit, as the larger distance from the driver to the mirror enables the wide-angle lenses installed at the top in the mirror housings to be viewed at a more favourable angle.

At night-time the Setra lights up as standard with new integrated LED main headlamps. The light from these headlamps is similar to daylight and is thus less tiring on the eyes than conventional halogen light or xenon headlamps. At the same time, the LED lamps offer a service life roughly equivalent to the vehicle's lifespan. This cuts out the need to change lamps, saving money and downtimes. The new lamps also enhance safety, as a Setra double-decker bus will never be on the road with lamps lit up on one side only.

Luggage compartment capacity slightly increased, additional stowage compartments

As on the predecessor model, the luggage compartment with a practical smooth surface on board the new double-decker bus is accessible via a large rear-end door and side stowage flaps. A space-saving side step in place of the previous step has allowed a slight increase in surface area, as a result of which the luggage compartment now has a volume of 8.4 m³. At the same time, this measure has also created space for a tool compartment and an additional practical stowage compartment in the entrance.

There is also a new stowage compartment in front of the front axle, under the driver's cockpit. The familiar stowage compartment under the axles between the platforms on the right has also been retained.

Engine and powertrain: perfectly coordinated all-Daimler engineering

The powertrain of the new double-decker bus employs both cutting-edge and established engineering and technology. The most recent update took place in the autumn of 2015 with the introduction of the latest-generation Mercedes-Benz OM 471 engine. The all-Daimler powertrain sets benchmarks in fuel efficiency and reliability and is tailored precisely to the needs of buses and coaches.

Setra renewed the entire powertrain and suspension of the predecessor model back in the autumn of 2013, to tie in with the introduction of the Euro VI emissions standard. The OM 471 six-cylinder in-line engine with a displacement of 12.8 l replaced the previously employed V8 in the course of this overhaul. This engine continues to deliver an output of 375 kW (510 hp) and an exceptional 2500 Nm of peak torque. The numerous outstanding technical features include common rail direct injection with the unique flexible high-pressure X-Pulse injection system. The engine is extremely fuel-efficient and is a smooth-running, clean and extremely reliable operator. Long maintenance intervals of up to 120 000 km for engine oil changes and 360 000 km for initial cleaning of the particulate filter (every 240 000 km thereafter) lower costs and cut downtimes.

Setra also introduced the fully automatic GO 250-8 PowerShift bus transmission in the course of the overhaul. The features of this perfectly stepped transmission include fast and barely noticeable gear changes and a crawl function for delicate manoeuvring.

The engine power is transmitted to the RO 440 bus drive axle, which also underwent extensive optimisation measures. The overhaul has resulted in a further reduction in friction and subsequently more economical and quieter operation – the latter being a key factor particularly on the lower deck of the double-decker bus. A trailing axle with independent wheel suspension enhances ride comfort, improves handling and lowers the vehicle's weight.

The latest engine generation: showing how a good thing can still be improved upon

The latest generation of the OM 471 engine has been demonstrating how a good thing can still be improved upon since the autumn of 2015. With a higher maximum injection pressure, increased compression, a redesigned combustion chamber, a patented exhaust gas recirculation process with flexibly controlled return flow rate, asymmetric injection and a new turbocharger, built in-house, what we have here is a whole bundle of measures that add up to reduce further the already advantageous fuel consumption. At the same time the complexity of the engine design has been reduced by a fixed turbine geometry for the turbocharger, the omission of wastegate valve and boost pressure control, plus the elimination of the EGR sensor and EGR control, thereby also increasing its robustness.

Duly prepared, the new double-decker bus is all set to begin its working life with a perfectly coordinated and well proven powertrain: OM 471 engine rated at 375 kW (510 hp), fully automated GO 250-8 PowerShift bus transmission, RO 440 bus drive axle.

The unparalleled economic efficiency of the double-decker bus

Predictive Powertrain Control (PPC) and Eco Driver Feedback (EDF) are optionally available to support the driver with individual feedback on their personal driving style. With this combination, long maintenance intervals and its aerodynamically perfected body, the Setra S 531 DT of the TopClass 500 exploits all savings potential to the full for unparalleled economic efficiency.

The vehicle's exceptional maintenance-friendliness is also a factor here. This was an important consideration in designing the new double-decker bus. By way of example, the cooling system on the right side of the bus is now ideally accessible by means of a large maintenance door, as opposed to the previously employed two service flaps. On the opposite side of the bus, another large maintenance door affords access to the exhaust system. A new large maintenance flap on the outside of the vehicle facilitates emptying of the waste receptacle. This flap also offers improved access for any maintenance work on the sanitary installations.

The Setra's gentle comfort suspension

Drivers and passengers alike will benefit from the suspension which has been adopted unaltered from the vehicle's predecessor. The double-decker bus rolls along particularly gently on its full-size 315/80 R 22.5 tyres. The Setra-designed front axle, the RO 440 bus rear axle and the actively steered trailing axle with independent wheel suspension all contribute to excellent ride comfort. A turning circle of 23.1 m makes the 14 m long touring coach surprisingly agile, while its large ground clearance ensures the required everyday practicality, for example when negotiating ramps.

Photos and text: Daimler AG - Setra buses and coaches


gedruckt am 16.04.2024 - 01:07