It was during the year 2006, National Urban Transport Policy, promulgated the modern technologies for public transport with focus on bus based systems. Until such time, there wasn’t a need felt for a specifically designed Urban bus. Due to continuous thrust, a bus specifications for urban services were developed. Inorder to have a uniform design recommendatory Urban Bus Specifications (UBS) released by Ministry of Urban Development in the year 2008. Subsequently recommendations became mandatory and based on the UBS more than 13000 buses were procured in JNnurm1. Now with the base set, there were continuous improvement going on in the UBS, as the Committee received several inputs from the execution of JNnurm 1 as well as from various stake holders.
The Committee, which comprised representatives of Ministry of Road Transport & Highways, Ministry of Heavy Industries, SIAM, IABM, ASRTU, CIRT, ARAI, Bus Manufacturers, OEMs, Experts, by collating all the inputs, released Urban Bus Specifications 2 – UBS2, during 2013. Though there were several important specifications mandated, one of the most welcoming one from the driver community was mandating Automatic transmission for Std buses. Until then Automatic transmissions were limited to some high end cars and to premium city buses like Volvo 8400. While every manufacturer took the full automatic route or torque converter route, Ashok Leyland took the Automated Manual route – Leymatic. Ashok Leyland was working with ‘Leymatic’ for quite sometime since 2010 even before there were a sense of bringing Automatic transmissions under UBS.
The technology partner for Ashok Leyland is WABCO and being a Global leader in AMT, the first AMT was designed and developed nearly 30 years ago and WABCO’s manufacturing center of excellence in Hanover, Germany, produced its 3,000,000th Automated Manual Transmission, in 2015. WABCO’s AMT systems are available from 5- to 18-speed applications, including its breakthrough OptiDrive modular AMT system. Many global manufactures including Volvo, MAN, Iveco continue to use the base system from WABCO. WABCO and Ashok Leyland joined together to develop ‘Leymatic’, an Ashok Leyland way of AMT systems.
Leymatic – Back ground
Though the system is more helpful in city traffic, the first bus to feature ‘Leymatic’ was a Ashok Leyland 12M, and the operator being K.P.N Travels from Salem, Tamil Nadu in 2011. Back then this bus was working between Trivandrum and Bengaluru. Subsequently VRL Transports converted around 140 buses with Leymatic, starting from 2013. Post mandate from UBS2 for automatic transmission, Jan Bus was launched with Leymatic. Ever since they are more than 500 buses running across India with various STU’s. One of the early adoption of AMT’s by Ashok Leyland was, it was having a chassis with all necessary requirements meeting the AMT. Though Ashok Leyland was famous for mechanical engines, they were offering common rail engine which were fully electronic, there by enabling the integration of AMT system.
Comparison between Automated Manual with Manual and Automatic Transmission
Viking with Leymatic
Viking is versatile platform and is as generic as a Bi-Cycle, which can be used in any terrain, application, segment. Post BS4 migration one of the early sale of Viking 222 BS4 was to an operator called Vee Vee Transports in Coimbatore. This operator owns more than 60 buses and they are operated in Stage carriage, city, tourist and staff transportation. One of the bus running as city bus is now fitted with ‘Leymatic’ AMT. The system has various modes like Economy/Power mode, Manual/Auto mode, Crawler mode.
Modifications as against stock Viking
Viking normally comes fitted with four finger, axial spring, 14″, mechanical clutch and this is now replaced with diaphragm type 15″ pneumatic clutch. A separate MID display unit is now fitted which displays various modes and the gear in which the bus is travelling. The bus runs in a tough city route almost diagonally intersecting the city.
Route No – S7
Route – Ondiputhur to Kovai Puthur, Coimbatore, Tamil Nadu.
No of Trips per day – 14
Total distance covered per day – 372 Kms.
Time of operation – 06 05 to 2345 (Almost non Stop).
Our Drive and Travel
Like every other report we at CV News.in, took a drive and travelled in the bus to bring out an Exclusive story about the New Bee in town. We choose the 16 00 o Clock trip as this is the most crowded trip and on an average close to 150 passengers travel during peak hour. Overall this is a brand new bus with just 37000 odd Kms in the odo. The engine develops a power of 165 hp and torque of 550 Nm and has a wide bandwidth from 1300 rpm all the way upto 1800 rpm. The gear box is same – 6 speed S636 with a first gear ratio of 6.72 and has a over drive as well. Overall since the drive line hasn’t changed, initial pickup and spacing between gears are all same.
Now with respect to AMT, in the economy mode the gear shifts between 1650 to 1750 rpm and in power mode shifts between 2000 to 2100 rpm. Even in Economy mode the first to third gears shifts at 1750 rpm and fourth to sixth shifts at around 1500 rpm. This is due to fact that, bus is mostly overloaded and requires a higher torque to start and once the bus starts to move, the momentum keeps it going. Though when used in Auto Mode, the system allows manual over ride either to upshift or downshift depending upon the engine rpm. Even within crowded city traffic, there isn’t much need for manual shift or manual over ride and the auto setup just runs fine. The only small niggle is, time taken for shifting gear and this should have been slightly lesser. This at times lead to a torque drop, though not to the level of stalling but driver has expressed concern over Turn Around Time. Since the engine has a moderate torque rating of 550 Nm it doesn’t have so much reserve torque to pull seamlessly, when there is a delay in shift. This is noticed especially in the peak crowded hours.
Over all, the drive is smooth but still Ashok Leyland and WABCO engineers are working on further optimising and fine tuning the system. Even with current condition, the bus is delivering 5% better fuel performance than what it was delivering with manual transmission. This is a huge saving considering the duty cycle of the bus and the route it is deployed. Infact the primary Key Buying Factor in this route is Turn around time and not the fuel performance. Mr. Veerakannan, Owner of the Company is extremely happy with the system and is even planning to deploy women drivers. Now the drivers are happy to take one shift more as they enjoy the “Clutch pedal less” travel.
Leymatic Vs Experienced driver
So now come a million dollar question. Will Leymatic, for that matter any AMT is better than a best driver? Not necessarily and although none of the system can match a best driver. Even then, AMT has proven to enhance fleet fuel performance, anywhere between 5% to 7%. This is because of the reason, no matter who drives, the gear utilization and gear changing frequency is same for the said terrain, and is an outcome of the software, which is further fine tuned for fuel performance, yet without compromising vehicle performance. When you have a fleet of 300+ vehicles and is driven by atleast 600 odd drivers, driving pattern is going to be different.
Few are best, many are better and some may be worst. Now with AMT in place, the nominal curve of fuel performance becomes narrower and hence the spread is less. When the spread is less, the variation is limited and this translates to uniform fuel performance figures. With variations reduced there is a huge cumulative savings in fuel and is recurring. That’s the underlining selling point here.