Switch EiV22 driven: Mumbai's new electric double decker bus

Recently, I drove one of the smallest EVs there is, the Tata Nano-based Neo. This week it’s one of the largest. Nearly five metres high, roughly ten metres long and large enough to make a dinosaur sit up and pay attention, India’s first electric double-decker bus is so big, I let off an unprintable expletive once I’m up close. And the closer I get, the bigger it looks. It’s no extinct dino though; far from it. An all-electric bus built by a company that has seen huge success with e-buses around the world, this is the made-in-Chennai Switch EiV22.  

What is the Switch EiV22? 

So what exactly do we have here? The e-double decker is put together by a company with vast experience in both buses and EVs. Switch Mobility was created by the coming together of Ashok Leyland and Optare of the UK. The former needs no introduction here in India and the latter has over a century of expertise in bus design and manufacturing. 

When the first tender for BEST’s double decker was floated, Switch looked at the electric double decker in the UK. But this proved to be unsuitable, according to Switch Mobility Ltd CEO Mahesh Babu. The low 300mm floor bus would not work on Mumbai’s roads, the air conditioning would have to be beefed up and then there was also the small matter of the bus costing £6,00,000, or roughly Rs 6 crore. So Switch decided to make one for India. It started with its made-in-India nine-metre single-deck EV bus chassis and designed a double decker with a steel and aluminium frame around it. Floor height now was 900mm, the chassis was strengthened to take the additional weight and bending load of the extra floor, and the bus was given larger anti-roll bars for better stability. Switch also used air suspension for the rear and the 1.5-tonne battery was placed under the main chassis rail for greater stability. 

Switch EiV22 exterior and interior

While the bus has been designed by Switch, the body of the bus is actually made in Mumbai at coachbuilder Antony. A thoroughly modern-looking double decker, this bus looks like it is shrink-wrapped in glass and acrylic panelling. The front is practically all glass. The top and bottom windscreen are joined with an acrylic panel for a modern, flush one piece or pillarless look, and adding to this, the nose gets a whole array of tiny but powerful LED headlights. Around the side, you get something we are all familiar with, a ‘floating roof’; and what looks particularly attractive is the heavily tinted green glass that lights up when the sun hits it. What also looks cool is the manner in which the roof dips towards the rear and the waistline flicks up. Neat.

There’s no rear windscreen on the lower deck. Sat behind the perforated metal panelling is the aircon system and under the rear deck lid, the Motor Control Unit, battery management system and hardware for the twin chargers (placed on the right of the bus). Further up near the axle is a massive coffee table-sized permanent magnet  motor made by Dana in Pune. Forget the 320hp it makes, you need torque to move mass and this motor churns out a staggering 3,100Nm. This version of the bus also comes with a 231kWh lithium-ion battery pack that can be charged in an hour and a half by twin DC charging guns via its 650-volt system.

The bus is also modern on the inside. Large, fixed windows, airliner-like twin aircon ducts on the roof, CCTV cameras and a public address system. There are also panic stop buttons all around as well as hammers placed near every window in case of a fire. The bus comes with automatic and manual fire extinguishers, remote battery monitoring and a button that decouples the battery in an emergency. There is scope for improvement on the inside, however. Fit and finish in places isn’t as good as it should be and space on some of the seats is compromised. 

Switch EiV22 ride and handling

Now for the difficult bit, getting behind the wheel. I notice I’m sweating despite the air conditioning. The power steering-equipped wheel isn’t very large, and as I release the hand-operated air brake and select D, the massive frame of the bus shudders. Problem is my right foot. I’m just not ready to release the brake. What if this apartment-block-on-wheels shoots forward with all the torque coursing through the system? What if it lurches, porpoises, starts doing a bunny hop. But as I release the brake gingerly the double decker edges forward smoothly; no jerks, no oscillations. Phew. And soon after, I get softly on the throttle and pull away. Throttle responses, thankfully, are not spiky, but you can feel the huge amount of twist it has as soon as the electric motor starts to spin.

Once on the move, I start looking out for low-hanging branches, badly strung cables and overhanging roofs. The fear of hitting trees, especially, with the top of the bus is real. It’s why the new age ‘glass’ double deckers with their wraparound windscreens have metal braces. While the feeling of driving a piece of real estate never does leave you, the dimensions of the double decker trouble me less the more I drive it. And it’s only then that I realise just how agile it is for its size. The flat steering needs some twirling, sure, but the bus isn’t hesitant to turn. What also helps is that visibility is good. Soon I’m using more throttle, I’m turning with more speed and confidence, and what impresses me most is just how well balanced this tall boy feels, despite the lean. Crazy thing is I’ve driven utility vehicles and SUVs that have rolled more than this double decker. Guess the stout anti-roll bars, the air suspension and the heavy batteries placed low are doing their job well. Still, I’m sure it will be tricky when loaded and driven at higher speeds. Even the ride is good for a bus. There is some amount of movement, but as this is no monocoque chassis, it’s only to be expected. 

The brakes, however, need some getting used to. Initial retardation is only average, which is fine at low and medium speeds, but what takes some getting used to is that braking feel and feedback vary. Despite this, the bus has disc brakes up front, anti-lock-brakes and even hill-hold. What we’ve also learnt is that the remaining 198 buses from BEST will all come with ESP or an Electronic Stability Program. Wish they’d retained the manual air horn though, like they’ve retained the old style bell. Sometimes old tech is just better.

Mumbai double decker bus: what's next?

Double Decker buses have been around in Mumbai for 86 years.

Double deckers are part of Mumbai’s heritage and have been around for 86 years. They are also practical, carry nearly twice as many passengers, are 36 percent more energy efficient and take up less road space for the number of passengers they carry. Switch’s EiV22 will also not put out any local emissions; it is nimble and will keep up with traffic and many will be happy to travel in air-conditioned comfort. Would love to ride on the top deck along Mumbai’s upcoming coastal road; wouldn’t that be fun!

In conversation with Switch Mobility CEO Mahesh Babu:

Q: How different is the Switch EiV22 from the usual diesel-powered double decker bus? Has the single-decker chassis been upgraded to be suitable for a double-decker body?

A:  We stopped building diesel-powered double decker chassis long ago. We now have a 9-metre-long EV chassis on which the Switch EiV22 double decker is based. The body is built with a mix of aluminium and composite material.

Since the battery is positioned in the chassis, the centre of gravity has to be lower and most of the weight is below the waist and this helps in stability. That's how we took the 9-metre-long single-decker chassis, strengthened it and designed it to be suitable for an aluminium structure double decker body. And that's how we came up with the Switch EiV22 double-decker bus.

Q: What are the structural upgrades that you guys have done on the chassis to take the added weight, you know, because the battery and everything is the same, the traction motor and everything is the same?

A: The 9-metre chassis has the same motor, battery and architecture. What we have done is strengthened the chassis to meet the double decker’s weight; we’ve worked on the dynamics to cater to the tune of the double decker. We have met all the aggregates to meet the double decker’s load weight to take care of the performance of the bus.

The biggest challenge was to keep the weight below the 19-tonne category, and so we had to do an aluminium composite body.

Q: What is the difference in the chassis design of the diesel double decker bus and the new EV iteration?

A: Now it is totally different because that design is outdated. It is a design from the ‘70s, which is irrelevant now. For example, the diesel double decker had only rear steps, and customers complained that going up and coming down was congested. So we took all the inputs of not just our team but also customer usage and in our double decker EV, we added front and rear steps. We took all the inputs from customers, engineering from the old diesel double decker as well as the EV double decker in London, but we designed a new bus for India.

With inputs from Akbar Merchant