Roger Bedell of Furrer+Frey Opbrid proposes a tractor swapping model to electrify long-haul trucks using automated high power charging stations. This "Pony Express" model involves trucks arriving with low battery charges and swapping fully charged tractor units in under 3 minutes, allowing trucks to continue trips without lengthy charging stops. The model requires 400 kWh battery packs per tractor that can charge at 400 kW in under an hour between swaps. It could save up to €84,240 per year in fuel costs compared to diesel trucks and support electrifying freight transport to reduce emissions. Potential challenges include traffic delays and coordinating charger and tractor availability but the system may be feasible with proper logistics software.

1. Roger Bedell Product Director
Furrer+Frey Opbrid
Automated High Power Charger Stations
Contact: rbedell@furrerfrey.ch +41 31 357 6180
Electrification of Long Haul Trucks using
Tractor Swapping (Pony Express Model)

2. Motivation
“A number of studies suggest that in the 2020 to 2030 time frame,
heavy-duty vehicles are estimated to overtake passenger cars
as the largest global contributor to fuel consumption and
GHG emissions in the transport sector”

3. Motivation
Figure 3: New heavy-duty vehicle sales and fleet-wide fuel consumption in the U.S.

4. Per Mile (US) costs of
Tractor-trailer

5. Proposed Solutions
Overhead Catenary – Big Infrastructure
In-Road Inductive Charging – Big Infrastructure
Battery Swapping – difficult to swap the
very large batteries needed, expensive stations
Ultra-fast Charging
during rest times: heavier
LTO batteries, very high
Charge rates

6. Another Possibility: Tractor Swapping
(Pony Express Model)

7. Tractor Swapping – Step 1
Tractor-Trailer arrives with low
Battery charge
Fully charged tractor
waiting

8. Tractor Swapping – Step 2
Driver Unhooks Tractor
From Trailer
Driver switches
Tractors

9. Tractor Swapping – Step 3
Truck departs with
Full battery
Tractor charges

10. Enabling Technology 1:
Jost KKS Automated Coupling System

11. Enabling Technology 2:
Furrer+Frey Opbrid Trůkbaar

12. Advantages
• No large infrastructure projects needed
• No ultra fast charging needed – high energy batteries
can be used for longer runs between charges
• Simple, inexpensive and proven equipment
• Fast and safe. Swap in just a few minutes for a
fully charged battery.
• Available today

13. Disadvantages
• Without good scheduling, tractors can be left idle
too long, raising capital costs
• Tractors and trailers need to both have the KKS
System for fast swaps, though manual swapping
is possible
• Delays in one area can affect the entire system –
similar to airport delays
• New business model, favors large shippers.

14. Possible Scheduling
• Truck departure headway timed to allow enough time
to charge, perhaps 60 minutes (1C charging)
• Time tractor swapping should coincide with mandatory
driver breaks to reduce the down time associated with
leaving and entering the motorway
• Best for large wholly owned fleets or a “Tractor
Sharing” business model

15. Example: Rotterdam to Zurich

16. Schedule (assuming 90km/h)
• 08:00 Depart Rotterdam
• Drive 2 hr 15 min (200km)
• 10:15 Mandatory 15 minute break, tractor swap
• Drive 2 hr 15 min (200km)
• 12:45 Mandatory 30 minute break, tractor swap
• Drive 2 hr 15 min (200km)
• 15:30 Mandatory 15 minute break, tractor swap
• Drive 2 hr 15 min (200km)
• 18:00 End of driver shift, max 9 hours reached,
• Destination reached.
• 4 swap/charging stations needed.

17. Battery Requirements per tractor
Range needed is about 200km + extra for wind, traffic, hills
Tractor-trailer fuel consumption is approx. the same as
a 12m bus at ~37l/100km, or ~1kWh/km
Assuming 2kWh/km gives a battery of 400kWh
Using available NMC batteries with a pack level energy
density of 110Wh/kg = 3600kg

18. Battery Requirements per tractor
Litarion NMC cycle life 9000@1C/1C, 3000@3C/3C
Makes economic sense to extend cycle life by charging at
1C (400kW) instead of 3C
Double the energy density of LTO, ½ the weight. Similar
Cost/kWh/cycle
Duty cycle 2.25 hr driving/1 hour charging at 400kW (1C)

19. Equipment Requirements
Ratio of 3.25/2.25 tractors per load = 1.44 tractors per load
But with some built in time for delays, 1.75 tractors
Per load is likely more reasonable.
Driving time of tractors depends on operation hours.
Assuming 18 hours per day of operation, tractors will
Charge 18/4 times per day = 4.5 times per day.
4.5 * 300 days = 1350 times per year, or 6 year lifetime.

20. Economics
Fuel cost is the largest portion of per mile trucking costs
Average fuel consumption is about 37 l/100km in both
US and EU (similar to 12 meter buses)
Fuel costs of electricity are approx. 20% of diesel.

21. Economics
If a load is moved 800km per day, savings by
electrification can approach
0.39 l/km * 75% * 800km * 1.20 €/l
280 €/Day * 300 days = 84.240 €/Year

22. Economics
Additional costs:
Batteries – battery cost is currently around
0.06 €/kWh/cycle(0.12 €/km) (Litarion NMC-9k cycles)
Extra Tractors – more tractors are needed, though each
tractor will last longer since it runs fewer km/year
Chargers, additional parking, and electrical infrastructure

23. Possible “Fatal Flaws”
• What about traffic jams? (accidents, construction etc)
• Will the drivers want to do it? (No idea)
• What if all the chargers are occupied? or, what if there
are no charged tractors ready? (Logistics software)
• Will this work with driverless trucks? (Yes!)
• Swapping time is considered driving time, so this may
eat into driver’s allowable time. (True)
• Too difficult to implement (Incentive likely depends
on direct and indirect financial benefits)

24. If electrifying is doable, we must do it now.
Global warming is a real and present
danger, and we need to stop burning
fossil fuels.
Contact:
Roger Bedell, Product Director Opbrid
Charging Systems
Furrer+Frey AG, Bern, CH
rbedell@furrerfrey.ch
+41 (0) 79 609 5120