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routeone Issue 702 - 9 August 2017

theoretical maximum 400bhp of its engine and motor combination. Optimum fuel effi ciency is achieved by using a mix of diesel and electric power. From stationary the i4H uses the electric motor. The engine engages as speed rises, although it runs whenever the coach is moving even if at idle. It switches off when the handbrake is applied. At higher road speeds, power from both sources is ‘blended’, and when slowing or descending hills the engine is disengaged to permit maximum regeneration. “The i4H is designed without any fundamental changes to the existing model and that is one of its principal attractions,” says Mrs Hartley. “It was a joint decision by Irizar and ourselves to make the UK the second country to get the hybrid coach, which is an indication of the potential that we see for it here.” Operators attending the dealership’s I-Drive event at Rockingham Raceway on Wednesday next week (16 August) will have the opportunity to drive the i4H demonstrator. /IN SHORT: the hybrid package – including batteries – is contained entirely within the engine bay. “The i4H integral has the same ‘envelope’ as a diesel, extending to luggage capacity and saloon layout,” says Mrs Hartley. Irizar UK has specifi ed the high-fl oor, sunken-gangway demonstrator with 57 i6 seats, making it suited to commuter work and longer-distance duties. Its nearside centre door includes a step-mounted wheelchair lift; a removable platform on which two seat pairs are mounted is opposite, and a wheelchair user would travel there. The dealership will also be able to supply a mid-fl oor i4H where the seat plinth is lowered to sit fl ush with the aisle. That gives rise to the possibility of 70 seats, and Mrs Hartley does not rule out a lower-fl oored example if demand dictates. “Anything that we can do with a diesel i4 integral, we can do with the i4H,” she says. The model can be PSVARcertifi ed if required, making it suitable for use on local services. Under the bonnet Where the i4H differs from other Irizar integrals is under the bonnet. It is the fir st for the UK to have a Cummins engine, with a 6.7-litre ISB6.7 developing 300bhp coupled to a Fuller hybrid package that includes a sixspeed automated gearbox and a 100bhp electric motor. A visual comparison of the hybrid and diesel integral rear modules shows that they are completely different. The hybrid has a large black box to the left of the engine that houses the lithium-ion batteries, and its radiator is longer; cooling fans are electrically-powered, rather than hydraulic. Irizar is also at pains to point out that the hybrid package is very simple. How does it work? While the i4H does not yet have zero-emission capability, Irizar continues to develop the hybrid driveline, including the addition of higherpowered versions. Currently, the most that the i4H can deliver is 350bhp, and not the i COMMENT Although the i4H integral is already in service in Madrid, its arrival in the UK gives an indication of where Irizar thinks the coach market may go long term. In buses, it was quick to tie its fl ag to the electric mast, and history so far shows that it was right. Whether it will be so with hybrid coaches remains to be seen, but it has at least put the concept into the market and up for discussion. The i4H will bring alternative propulsion in coaches to prominence, and it is a subject that deserves attention. Irizar has done well to package a hybrid driveline that does not affect carrying capacity, and it will be interesting to see where the project goes over the coming months and years. /FIND OUT MORE: bit.ly/2hxnZZv s Parallel hybrid power Parallel hybrids utilise diesel or electric power, or a combination of both. That gives the benefi ts of electric propulsion at lower speeds, but when cruising the diesel engine can take over for optimal effi ciency. At times of high power demand both function in parallel. When slowing, the electric motor functions as a generator to recapture energy that would otherwise be lost. 9 AUGUST 2017 ROUTE…ONE.NET / 7


routeone Issue 702 - 9 August 2017
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