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Wednesday, June 22, 2016


Sky bus technology is developed by Mr. B. Rajaram. He was involved with the Konkan railway project from the beginning of construction (1990) as a Chief Engineer, Director (Projects) and finally as the Managing Director (1998 to January 2005).Sky Bus Metro concept first presented in Bologna University Italy, by him in 1989.
The Sky Bus technology meets the requirements, and re-defines the thinking and planning for urban transport being an ecofriendly Mass urban transport system revolutionizing urban life. It is a patented technology developed for the new millennium and will cause a paradigm shift in urban transportation all over the world. Being an indigenous technology, it will place India on the forefront of the Rapid Transit Industry all over the world while providing the much needed alternative transportation solution, which is financially viable, environment friendly, synergizing well proven existing cutting edge technologies. Sky Bus is based on the concept of Sky Wheels presented in 1989 at the World Congress for Railway Research by Mr. B Rajaram, Managing Director of KRCL at Bologna University, Italy. The sky bus uses pre - fabricated latest construction technologies, which in busy urban areas without disturbing the existing traffic pattern. All these structural engineering methods are well -proven. They have IT tools for economical communication and control. The 3 phase asynchronous AC electrical motor used for the propulsion of sky buses is also well proven and widely used abroad as well as in India.
It is aesthetically pleasing and there is no concern of a claustrophobic feeling for road users. Aesthetic, and eco-friendly, the Sky Bus is protected against derailment, toppling or collision - by design as well as by construction, hence is safer than the existing rail based system. At the cost of Rs. 50 Crore per km. in India, the system is noise - free and pollution - free with a capacity to transport 36000 passengers per hour (pph), scalable to 72,000 pph as required. With no signaling and having no points and crossings, it is a unique mass-transit system that can be put up within two years in any crowded & congested city. In addition to moving people, the Sky Bus system can carry standard 20 ft. containers, boosting its capacity utilization to double that of other existing systems.
The Sky bus is essentially a fusion of a bus and a train. Its carriage looks like a bus, but it runs like a train. It is located 8m above the road level. Heavy 52/60kg rails are placed at standard gauge, floating in elastic medium and dumped by inertia of measured mass held in 98m x2m box enclosure. Rails are supported by the columns having diameter 1m having a spacing of 15m and located at 15m distance from each other. Above that columns support and guidance for boggies are provided which can run at 100kmph with coach shells suspended below it carrying passengers in air conditioned comfort. The coaches can never escape guidance system and jam over tracks. But same speeds as carried in regular high speed metro rail can be handled by Sky bus.


Fig 2.1 Components of sky bus
The system Sky bus metro consists of several conventional and some new proven technologies, which makes the sky bus more efficient. These are designed so that to keep the sky bus moving without any defect and to give the passengers the ultimate comfort along with other luxurious facilities which they cannot get in the local buses or in trains. The various important components of this system are:
• The sky way
• The sky bogies
• The sky coaches
• The sky stations
• The traverse arrangements

 The sky way consists of a concrete box structure 8.4 x2.4m carried over a series of piers at a height of about 9-10 m above existing road level. In the middle of roadway pile foundations support 1m diameter columns spaced at 15-25 m along the roadway in the median of the road. Two rails fixed with appropriate fastenings within the concrete box support and guide the sky bogie. In addition, the closed concrete box includes sufficient walkway on either side of the tracks, so that people could walk in the closed concrete box for inspection and maintenance.

Fig 2.2: Sky way
The top of the closed concrete box, which runs continuously on the columns, could be used innovatively, such as a strip park open for pedestrians or for other appropriate uses. The concrete columns could be placed at 15 meters or less depending on the street conditions in the urban area and curvature of the sky way in curves. The height of the sky way is also dictated by the street conditions, such as minimum clearance, similar to bridges and potential joint development opportunities.


Fig 2.3: Sky bogies
Standard two axle bogies can be used in metros for speed of 100 kmph (but can have higher speed, if required, up to 160 kmph) of standard gauge. Linear induction motor technology is incorporated with 4th rail driving which is above the bogie and 3 Phase AC motors with regenerative power capability. Third rail is used for current collection. Emergency mechanical brakes are also provided. They are also regenerative type.


Fig 2.4: Sky coaches
The sky coaches are suspended from the bogies. Each coach is designed to 10 carry about 150 passengers. The sky bus can be formed with 2, 4, and 6 coaches resulting in bus capacities ranging from 300, 600, and 900 passengers per bus, respectively. At headway (time between successive trains) of 40 seconds, the directional capacity is in the range of 27,000 to 81,000 passengers per hour. At one-minute headways, the directional capacity is in the range of 18,000 to 54,000 passengers per hour. These capacities are sufficient enough in urban areas of many developing nations. The coaches are made up of double walled light shells with large windows. They can negotiate even 100-meter radius curves under controlled banking. Each coach is provided with 4-meter wide sliding automatic doors. The width of the doors is considered to be sufficient enough to empty fully loaded coach (150 passengers) and fill to its full capacity in 20 seconds. The interior of the air conditioned coaches can be designed to optimally mix seated and standing passengers depending on the transit function of the system, such as short shuttle operation and line haul operation. The Coaches are equipped with audio visual equipment to enable communication with passengers in the car. The Integral Coach Factory (ICF) of the Indian Railways has manufactured and supplied 35,000 coaches. It has a manufacturing capacity of 1000 coaches a year and exports coaches to several developing countries.


Fig 2.5: Sky stations
Unlike conventional mass transit systems, sky bus needs smaller stations about 50m long. Stations are available at every 1 km. It is a natural footbridge across the road. From up line to down line the station provides natural access which is easy. Service is provided at every 2 -3 minutes and thereby there is virtually no waiting time for passengers. Totally automated without drivers or guards and access control is also electronic by prepaid cards being swiped in. Station act as only access facility, and not as passenger holding area. Stations are elevated from the ground level and easy to access in mountain region since all village towns are located at high level. Stations are designed with 18-m length platforms to serve 2-car trains. Stations can be equipped with automatic fare collection system using prepaid card swiping mechanism. The elevated stations can be connected to the road level by staircase and/or elevators. The stations can be free standing or can be incorporated in other buildings such as railway stations, hotels, and shopping centers to achieve better access through joint development opportunities. The stations are designed to be simple and functional. Indian Railways has sufficient expertise to design, operate, and maintain these kinds of stations.

In order to change bogies from one track to other or to shift to a track leading to maintenance facility without using switches and sidings, an innovative facility called Traverser is developed The facility automatically lifts and shifts the sky bus trains from one track to other. Traverser is based on the experience with the proven load movement technology used on large manufacturing workshop floors. There are no points and crossings.

Fig 2.6 : Traverser arrangements
Standard gauge rail tracks
60 kg rails are fitted with double elastic fastening, with a standard gauge of 1435mm. The sleepers are designed & tested with an axle load of 20 tone and resulting in a maintenance free track.
Driving bogies
The bogies used here are of same specifications as that in the case of metro rails such as 100kmph standard gauge 12 ton/ 14 ton axle load powered bogies with 4x110/115 KW asynchronous 3 phase motors with power – regeneration and capable of peak 1.3 m/sec acceleration
Breaking is of electrical regenerative type which is coupled with compressed air disk mechanical breaks and emergency /idling mechanical breaks for stabling
Crushing load for under frame
Under frame is able to take crushing loads more than 70 tonne.
Train unit
Each train unit is of 20m length and which consist of two driving bogies- the coach divided into 2x9.5 m long buses connected through vestibule door.
Capacity of 20m long train unit
Each Sky Bus unit having two compartments having a size of 3.25m x 9.5 and it can carry almost 300 persons at a time. The 20m units can be attached to form a 3 unit, 60m long train of 1200 person capacity.
Signal & train control
Simple three aspect signal system is used here that is in this case, each signal has three lamps arranged vertically. The top one is green the middle one yellow and the bottom one red. The red and green lamp indicates indications as in the two aspect system and the yellow lamp shows the caution indication. Signal is driven by line of sight by motorman, with additional unique safety layer of RAKSHAKAVACH, capable of providing 40 sec headway- but planned 60 sec.
Route capacity
A Sky Bus route can thus be designed at 60 sec headway, to carry 20000 to 70000 passengers per hour per direction in peak period.
Security and safety
Sky bus is controlled automatically by a continuous computerized central monitoring & control system with provision of audio/visual access for each coach for security. Distributed intelligence systems with redundancy to provide protection against swinging under wind loads/emergency localized control/prevent over-loading/ emergency evacuation guidance. The coaches can never escape guidance system and jam over tracks and hence avoid accidents.
Track changes and reversals at terminals
The reversal for the sky buses at terminal points, to change tracks or go to depots happens through traversers- mechanical auto driven systems capable of handling 60m consists of sky bus units.
Stations-elegant and small
Stations are 60m long to handle three units of sky bus, covering next 25 years of requirements-though initially only 20m length is needed.
Easy access
Access is from existing footpaths, climb limited to 6m for passengers- within 500 to 600m from wherever you are on the road having sky bus route.
Turning radius & gradient
It can be designed for 20m turning radius, and vertical lift, if needed- thus we can avoid totally demolition of any built up urban property, if needed.
On Line maintenance of rolling stock and tracks
Maintenance is through continuous monitoring of vibration signatures, and directed by need automatically by computerized only and periodic checks. All the sub-systems/ elements are to existing UIC/Indian Railway code practices applicable to railway transport.
Cargo handling capability
Cargo of standard containers are automatically delivered and cleared into and out of city.
Safety Certification for Public carriage
It will carry international class safety certification by renowned world class safety certifiers.
Terminal concept
Current concept of a railway terminal replaced in this “grid” system, by a 15 multi-point distributed discharge and access- almost eliminating intermodal transfer. Each station designed for handling whatever commuters can arrive on a 4m wide footpath – with waiting time less than one minute.
Land requirement for route, stations and at depots
All along the route the alignment is typically located on the median (1.2m diameter columns at about 15m spacing) of the road, needing right of way at 6.5m above the road, the fixed structure carrying railway tracks located at about 11m – thus avoiding effect to road users. Typical road widths normally of 10m all along and at station locations, 20m width for 60m length desirable. Depots will be outside the urban areas, needing about 25 hectares land for services for every 10 km route. Stations are located with access from existing footpaths, and over and above existing roadways, none of them longer than 60m to cater to next 100 years of requirements of city- practically requiring little land.
Power requirements
Typically for tropical climate conditions, for a module of 10 km route, 15 MW power needed covering traction and all services including comfort air-conditioning loads at stations.
Quality of service and pricing
With access within 500 to 700m walking distance, air-condition travel at 100 kmph, service available at less than a minute during peak hours, priced at Rs 1.5 per KM falling to Rs 1for regular travels with lead of more than 7 km can be provided.
Typical costing (year 2005-06)
For typical installation to handle 40,000 passengers peak load per hour, on a double line, the cost on turnkey basis will be Rs. 55 to 60 Cr. Per Km, and construction period less than 3 years, for a minimum module of 10 km route.
Sky bus works based on the principle of Gravity Power Tower (GTP).The Gravity Power Tower is set of networked microprocessors with controls on main gear system, the high speed power transmission cable and the rolling unit as well as with controllers of adjacent gravity power towers.

In this case There are no electric motors and the the fly wheel energy storage is only a secondary element, for receiving energy from the moving rolling unit, drive a dynamo to provide emergency lighting or siren as needed. The derailment preventer is a set of pair of solid rubber wheel sets mounted on extensible arms (4), which normally do not touch the sidewalls, but when either predefined acceleration limits (Bojji 1983, 1984) are reached or instruction received from the rolling unit controller, they get extended and butt against the sidewalls, to prevent derailment or escaping from the rail tracks, as well as built in disc brakes cause emergency braking, for which a compressed air cylinder provides the energy. The Rail module's steel wheel set exactly the same as used in rail roads, rides over standard rail track, the track having a running opening in the middle to accommodate the downward extended space frame spanning the two bogies. Effectively the Rail Module is rather simple, with no conventional traction motors or any traditional braking arrangements. The cargo container or the passenger coach is integrated with the Rail Module's space frame spanning the two bogies. The system Could be elevated or sub-way suspended coach type. The movement is totally controlled by the energy management and continuously positively held by the power cable and automated without any visible signals. Safety is enhanced as there is protection against derailment as well as capsizing of coaches, because the coaches cannot get separated from the tracks held inside the enclosure box, both for elevated and underground options of gravity Powered Rail suspended systems. Case of power supply failing and the train getting stranded in mid section away from station does not arise, because, unless adequate energy is available at the Gravity Power Tower to launch a suspended coach to reach the next station, the launching will not take place.

Fig 4.1: Gravity powered elevated transportation.
There is no emission of fuel burning or chances of electrical sparks or short circuits along the route of travel of the coaches, reducing vastly chances of fires and eliminating pollution too. The regular train signal control systems are eliminated in the Gravity Powered Rail system, as positive control by the launching and receiving Power Transmission cables make sure of safety of the moving coaches and automatically controlled by the computerized control of the Gravity Power Control in coordination with the on board computer of the rolling mass.

Fig 4.2: Gravity powered subway railway transportation.
The lifts providing the access and the emergency exit steps may be noted and sufficient provisions for safe transit and disaster preventing and mitigating steps can be built in just as in case of existing metro systems. The great advantage is the road grades can be followed as the rail based system is not dependent on the rail-wheel adhesion for tractive effort. Sinceexisting right of way of roads is used, the system can be implemented without delays and it is environment friendly with no emissions and reliable as gravity. Now for costs and impact on energy scene of a nation. Take USA as example. For every Mwh of gravity power delivered by Gravity Power Tower, we need 10 to 30% as electrical energy to recoup. Depending on the source of electrical energy, this cost this will vary. The basic infrastructure cost to provide the gravity tower is really comparatively quite low. So the impact on a country's energy scene, taking the case of USA is s away from the Tower using High Speed Power Transmission cables; the said gravity tower recovering back the energy of the 19 Power Mass Module raising the heavy masses back against gravity, from the kinetic energy of another approaching rolling mass through the High Speed power transmission cables, to the extent of 98 to 70% of the energy depending on the lead; the balance made up from external electrical source; a network of such Gravity Power Towers with High Speed Power Transmission cables linked with each other through rail/road or airways form the gravity power transport systems saving more than 70% of the energy used in transportation systems. Compared to electricity, gravity enjoys additional unique benefits of saving on generation and distribution costs. A case of 108 kmph peak speed urban transport with halts at 450 m is demonstrated to be almost completely powered by Gravity Power, needing less than 2% of electrical energy.

Several safety features, which are developed as technology initiatives for Konkan Railway operation and also innovative developments made specifically for SBM, assre given below


Fig 5.1: derailment arrester
The bogies are equipped with Derailment Arresters. The Derailment Arresters, which are instrumented solid rubber wheels, are connected to the 20 journals of the wheel sets of bogies projecting upwards (inside the concrete structure) leaving a gap of 15 mm to 20 mm between the rubber wheels and the surface of the concrete box top . During normal running conditions, these rubber wheels of the Derailment Arresters do not touch the inner roof of the concrete box maintaining the gap. When a running wheel of a bogie tends to leave the rail (i.e. when a running wheel climbs or wheel axle rises leading to derailment), before the flange clears the rail top, the rubber wheel of the Derailment Arresters attached over that erring bogie wheel touches the roof’s bottom inside the box. The touching of the rubber wheel of the Derailment Arrester with the bottom of the roof of the concrete box triggers the controlling computers to control the train’s speed and running. The erring running wheel will be pushed back to the rail guidance in the process and not allowed to leave the rail guidance, thus avoiding the occurrence of derailing. The bogie, if defective, could be removed at the next traverser.

The suspender rods, that connect the hanging cars traveling under the concrete box with bogies running inside the box on rails, move though two parallel slots continuously provided in the floor of the box.

Fig 5.2: Swing arrester
The hinge or pivot mechanism of the suspender rods are allowed to swing to a limited extent while negotiating curves and under normal lateral wind forces. In order to mitigate the swing beyond the accepted limit, Swing Arresters are attached to the suspenders. The Swing Arresters, which are instrumented solid rubber wheels, are attached to the suspenders leaving a gap between the rubber wheels and the bottom surface of the concrete box. These Swing Arresters works are similar to the Derailment Arresters. When the swing is beyond the permissible limit, the rubber wheel touches the concrete surface which triggers corrective action to control the swing by reducing the speed or stopping the system.
An extensive ACD network has been developed by KRCL for the use of intercity rail operation. SBM technology uses the ACD network concept. The ACD network is intelligent microprocessor-based equipment consisting of a Central Processing Unit and a Global Positioning System with a digital radio modern communication system. The components of the ACD network are located in the front and last coaches of every train and in stations. All these components in the ACD network exchange information among them and automatically take decisions to prevent collisions. SBM has the ACD network, and bogie-mounted disc, regenerative, and mechanical brakes to prevent any collision. Even if all these systems fail, the impact of collision will be taken by the under-frames of the bogies running in the overhead concrete box. Passenger coaches, which are hanging from the bogies are just subjected to swing in longitudinal direction, the intensity of which depends on the severity of the collision.
The electrical equipment, driving motors, and other probable sources of fire hazard are located in the over-head concrete box, away from the passenger coaches. Any fire related to the electrical equipment is restrained to the concrete box. If there is any smoke, it will rise above and away from the passengers in the cars, thereby avoiding asphyxiation, the main reason of deaths in transit cars.In the case of a passenger car to be evacuated and it could not be run to the nearest station for emergency evacuation, the following additional facilities are provided for emergency evacuation of passenger coaches:
 _ Bring another passenger coach on other track, and shift the passengers from the problem coach to that car via extension walkways connecting the two 22 coaches.
_ Use emergency sliding chutes, as in an aircraft, provided at either end of each passenger coach to evacuate passengers to the ground.


Table 6.1: Comparison of sky bus and metro

1. In this new technology of Sky bus, almost no land acquisition will b’’e required, except for providing for right of way on existing roadways
2. Only at terminal points, of about 2000 to 4000 square meters of area will be required, that too at places away from the urban centre.
3. No demolition of structures or no gardens will be destroyed
4. No Vandalism. Not vulnerable to persons throwing stones. Track is inaccessible
5. Fastest evacuation in case of fire as compared to underground metros.
6. If at all derails, cannot fall down, coach keeps hanging. Hence no capsizing  takes place as compared to railways and underground metros.
7. No Deaths due to trespassing or falling off from train. In normal metros like Mumbai daily 2 to 3 deaths occur on the system with total casualties reaching almost 2000 per year.
8. Sky Bus follows existing busy roads, thus reaches the very heart of the city decongesting the roads. This is not possible in case of Normal Railway.
9. Capital cost is lowest. Almost 50 per cent of elevated systems and 25 per cent of underground metro required for same performance standards.
10. It has lowest running cost. Sky bus has maintenance free tracks, has no signals and points and crossings to maintain.
11. Sky bus does not make interference with normal road traffic. It does not require road over or under bridges.
12. Since the system involves guide ways in the sky, which does not fall into an exact definition of Railway, the number of agencies involved in clearing and executing the project will be minimum and only one authority at state level can be created for implementing the project
13. It can be built on roads with Fly over. It is not an impediment.
14. From the date financial closure is achieved, the project can be completed and commissioned within 2 years.
15. Sky bus riding is aesthetically pleasing and has no noise pollution.
16. Sky bus is insulated against floods, rains and obstruction on track
In June 2013, a multi-day cloudburst centered on the North Indian state of Uttarakhand caused devastating floods and landslides in the country's worst natural disaster since the 2004 tsunami. Though parts of Himachal Pradesh, Haryana, Delhi and Uttar Pradesh in India, some regions of Western Nepal, and some parts of Western Tibet also experienced heavy rainfall, over 96% of the casualties occurred in Uttarakhand. As of 16 July 2013, according to figures provided by the Uttarakhand government, more than 5,700 people were "presumed dead." This total included 934 local residents. The Indian Air Force, the Indian Army, paramilitary troops and NDRF team evacuated more than 110,000 people from the flood ravaged area Similarly On 3rd September 2014, Heavy rains lashed Jammu and Kashmir, including the summer capital Srinagar, for the second consecutive day Wednesday, triggering flood threat across the Valley. The water level in Chenab, Jhelum and other major rivers and streams in the State has risen overnight. The incessant rains, which threw life out of gear across Kashmir, also triggered a flood alert in South Kashmir areas. Many areas in Srinagar were inundated Wednesday due to heavy rains, disrupting normal life across the summer capital. People alleged the district administration has failed to tackle the situation emerging due to continuous rains. Srinagar city witnessed traffic jams for throughout the day, giving tough time to people. 
Over 250 people have died and thousands are stranded across the state, including Srinagar. The Army, IAF and NDRF are doing a massive round-the-clock rescue and relief operation, with 86 aircrafts and 30,000 troops. . If we have built Sky Bus in this Region the Scale of damage to life may have been reduced. Rapid transport system like Sky Bus can be built between the valleys and reduce the distance by half the time by the Road. Alignment of Sky Bus Route should be selected in such way the Maximum city in the mountain region is covered which lies along the bank or rivers. Sky bus is failed in Metro city but it will be Success in Mountainous Region. This can used as Disaster Management in rescue effort in evacuating people from the Region even road and Bridges are damaged in disaster prone area.
The Sky bus is the technological breakthrough that India has achieved. Sky bus is an improved railway technology, eliminating the problems of existing metro rail systems, like - derailment collisions and capsizing crushing people – which have been suffered by country for decades. Financially Sky bus metro makes urban transport dream come true for administrators and people. The sky bus metro is one single technology which can change the face of our cities, take out almost 10 million road vehicles in the cities and make the cities live able, improving quality of life and attract and sustain economic activity to generate wealth.
1. Drupad M.Dodiya, Mahavir A.Chopar, Prof.V.J.Chitaria, (2013) Feasibility study of Sky Bus in urban area, PARIPEX India Journal of Research, 2(4) ,187-189.
2. BalamuraliArumugam (2014), Feasibility study of sky bus metro Linking Cities in Himalaya Region, Civil Engineering Portal, SSRG International journal of civil engineering, Vol .1, Issue 5,pg 30 -32
3. Bondada, Murthy V.A. and Bojji, Rajaram 2005 Potential of APMs as Line Haul Systems in Developing Nations: A Case Study¡¬™Sky Bus Metro Technology, American Society of Civil Engineers, Automated People Movers 2005, CD ROM, ISBN: 0-7844-0766-5, Stock #40766.
8. Rajaram Bojji (2009)Alternate Energy : Gravity Powered Rail Transportation Systems ,IJR International Journal of Railway Vol. 2,pg 22-29
9. Bhaveshkumar M. Kataria, Dr. Neerajkumar D. Sharma, Bhavin K.Kashiyani, (2013) A Review on sky bus technology, A mass transportation system, IJSRD International Journal of Scientific Research and Development, Vol. 1,Issue 8,pg 1613 -1615


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