Charge of the heavy brigade

The road to carbon-neutral transport was never going to be a smooth one and arguably the route for heavy vehicles was likely to be the most difficult.

The reasons for that are fairly straightforward.

Additional battery weight for all-electric commercial vehicles is an issue, but the resulting potential payload restrictions are a particular concern for any operation where rates are based on tonnage delivered. Any restrictions on payload resulting from the heavy battery packs are not going to be favourably received.

With that in mind, it is encouraging to see the government’s proposed amendments to vehicle authorised weights affecting alternatively fuelled vehicles (AFVs) and zero emissions vehicles (ZEVs). As the government explains, the Trade and Co-operation Agreement (TCA) with the EU means the UK is already committed to allowing some AFVs and ZEVs to operate with an additional one or two tonnes of weight while on international operations (see box, right).

At the moment the same does not apply to journeys within the UK, but the proposed amendments would bring domestic routes into line with the weight allowances under the TCA.

ZEVs are expected to be given a flat 2-tonne increase to make an allowance for the weight of the batteries but the heaviest vehicles – 44-tonners on six axles and 32-tonners on four axles – have been specifically excluded from the increase.

This would mean that these vehicles are treated differently from LCVs with a maximum GVW of 3.5 tonnes, for instance, which benefit from a kilo-for-kilo allowance for equipment such as batteries up to a maximum gross weight of 4.25 tonnes.

We asked the DVLA why the heaviest vehicles are being excluded from the weight allowance. Although our question was not answered specifically, they did add context, explaining that it was considered important to align UK regulations with wider international counterparts while ensuring they are relevant for the transition to AFVs. In addition, some regulations have remained in place to align with the safe use of key road infrastructure.

On the face of it, 32-tonne GVW 8-wheel tipper operators who want to move to electric power are not getting much encouragement, as there will be no 2-tonne increase to compensate for the extra weight of batteries. Does that really mean it’s not worth considering?

Volvo is about to start production of its electric FMX models and these will include 6x2, 6x4, 8x2 and 8x4 models. Under the proposed changes, the 6x2 and 6x4 models will benefit from the extra weight allowance, even if the 8x2 and 8x4 models will not.

Since Volvo will offer models with between two and six battery packs, customers will be able to configure vehicles fairly closely to their needs, particularly where the 6-wheelers are concerned.

Compare and contrast

We asked Martin Tomlinson, head of media and truck demonstration at Volvo Trucks UK and Ireland, about the comparative weight of diesel and battery electric FMX models.

He says: “The like-for-like unladen weight difference, when you compare a diesel-powered FMX 8x4 with a full tank of fuel to an FMX Electric 8x4 with the maximum five batteries for the greatest range, is around 2.5 tonnes. However, an FMX Electric 8x4 is only available as a tridem because of the chassis space required for the batteries, and this chassis configuration – regardless of the fuel type – adds around another 500kg versus a conventional 8x4 layout.

“Obviously there’s an opportunity to reduce the number of batteries, depending on the required application.”

Using Tomlinson’s figures, each battery pack weighs around 500kg. If a vehicle was involved in local work, it might be possible to operate on three batteries instead of five, which would immediately reduce weight by around 1 tonne.

Tomlinson suggests that further weight reductions might be possible. “As demand for electric vehicles has shot up, battery innovation is also accelerating. Lithiumion batteries are already about a third of the weight and half of the volume when compared to lead-acid, and they will become even lighter and more powerful as the technology continues to improve,” he says.

“With the third-generation batteries coming later this year, we’ll shave off a further 10kg of weight per battery pack. But we are obviously looking at every possible solution to reduce weight further.”

Volvo is first to market with an 8-wheeler electric chassis, while other manufacturers are still finalising the details for their models. Sister firm Renault Trucks, for instance, also expects its electric 8-wheelers to be heavier.

“Details are not yet confirmed for Renault Trucks C E-Tech models, but they will offer reduced payload compared with diesel,” Andrew Scott, head of electric mobility and product development at Renault Trucks UK and Ireland, told MT

“Batteries have to be heavy to provide the required energy. For construction vehicles Renault Trucks’ electric installation will operate through the Optidriver transmission, so there will be no savings from a ‘simpler’ transmission. Note also three machines (motors that drive the axle and provide regenerative braking) coupled to the batteries, compared with the two maximum in the MD ranges.”

The full technical specification is yet to come, but Scott is mindful of the need to control weight. “Considerable efforts are being made to limit the weight of the vehicle and similar efforts have commenced with bodybuilders to optimise the weight of the body, but there is little excess weight to take away from electric versions,” he stresses.

2-TONNE TOP-UP

The proposed changes to weight allowances for ZEVs (not AFVs) will apply to: n 5- or 6-axle articulated trucks and road train combinations whose conventional technology weight limit is 40 tonnes; n As above but with 4 axles, normally limited to 36 or 38 tonnes; n 2-axle motor vehicles normally limited to 18 tonnes; n 3-axle motor vehicles normally limited to 25 or 26 tonnes.

Distance learning

This is the fundamental problem for all vehicle manufacturers. The weight gain is concentrated in the batteries and if an operator needs to be able to cover a certain distance each day, this will determine the size of the battery pack.

Similarly, the availability of rapid charging for a truck will determine how small the vehicle’s battery capacity can be.

DAF recently launched its XD distribution range, which will include heavy rigids. It has been designed to be powered by a range of sources including electricity.

When we spoke to Adam Bennett, DAF’s EV and sustainability manager in the UK, the government’s announcement about increased ZEV weight allowances had not yet been made.

“With the configurations of the electric vehicles (EVs), in the main part they take a modular approach, so dependent on the specification of the particular vehicle,

BITS AND PIECES: DAF says the modular design approach of electric vehicles in its latest XD range can help negate the battery weight issue

DESIGN DILEMMA: Weight savings on Renault’s upcoming C E-Tech models have been hard to come by, admits Andrew Scott, head of electric mobility and product development ➜ 14

PAYING WITH PAYLOAD: Operators needing a longer range and therefore more batteries will have to accept lower payloads, admits DAF UK’s EV and sustainability manager Adam Bennett n To explore the latest tipper technology, make sure you head to this summer’s Road Transport Expo. Register for your free ticket at roadtransportexpo.co.uk the allowance that we believe will be given by the UK government negates some if not all of the additional weight of the battery packs,” he says.

“You’ve obviously got some main components that aren’t there any more with the EVs, versus the previous diesel applications.

“In some instances, weight is certainly going to be a factor and those payloads will have to be considered and addressed for each operation, but in the main, the intention of the modular system and everything else along with the allowance is to negate a lot of that, so it has minimal impact to the end user.”

DAF’s 8-wheeler will have capacity for up to five battery packs. With the proposed weight allowance, if a customer chooses up to three battery packs, DAF believes the weight gain of the electric variant compared with diesel will be cancelled out. “If you go in excess of that threepack system, you then have to start considering the payload,” says Bennett.

SOLVING LONDON’ S WEIGHTY ISSUE

While the London Direct Vision Standard (DVS) favours low-mounted cabs, it can inevitably present a challenge for tipper chassis, which may need increased ground clearance when going off road.

The additional weight of a battery-powered vehicle could introduce a further complication – the need to maintain good ground clearance while still meeting the DVS, which is moving to a three-star rating next year.

“With our XD, whether it’s diesel or whether it’s electric, we can achieve up to five stars,” says DAF Trucks UK marketing manager Phil Moon. “We can achieve the very best standards and that’s a cab-design fundamental. I suppose it’s testimony to the fact that the New Generation DAF is designed with both electric and diesel in mind.”

Martin Tomlinson at Volvo Trucks does not see a problem here for the FMX Electric either. “The FMX Electric 8x4 can be specified to meet the DVS straight from the factory, and we expect this to prove the most popular specification for UK-market trucks, given the majority will be working in urban operations,” he says.

“All FMX Electric 8x4s will have full air suspension. While this reduces ground clearance, it brings the driver’s line of sight closer to that of other road users in towns and cities, benefiting safety.

“Plus, riding on full air suspension means the driver has the ability to temporarily raise the suspension when venturing off-road, to take advantage of the additional ground clearance as required.”

“Interesting one, electric tippers,” says Weightlifter MD Nigel Butler. “Clearly the technology is today more suited to urban operations, and any incentive the government can bring to encourage take up would be very useful.” If the current proposals become law, it does not look as though that will happen.

Reducing body weight could be another route for bodybuilders, but Butler is sceptical. “Any opportunity to minimise the weight of bodies has long been taken up with the adoption of alloy,” he says.

“There are certainly operations that would find it very difficult to make a transition to alloy [such as muck shifting and demolition-type operations].

“However, for those on not quite such arduous operations, I would expect that they will look to alloy builds as a matter of course. Additionally, we foresee a growing demand for alloy bodies complemented with a thin Hardox steel liner to part or all of the body, which will increase wear resistance.” n