Earlier this year, firefighters in Los Angeles proudly showed off their gleaming new truck. Like its predecessors, the truck was bright red and festooned with chrome accents and firefighting paraphernalia. But unlike the Los Angeles Fire Department’s other vehicles, this one had something special hiding underneath all those tools. This brand new truck, built by Austrian manufacturer Rosenbauer, wasn’t your traditional diesel-powered machine. Instead, this one was lauded as “America’s first electric fire truck” — though it’s equipped with a BMW-sourced diesel engine to top up the batteries if they run low.
That makes this a hybrid fire truck, not a pure EV, but that’s still a welcome development in the world of firefighting here in the States. The Rosenbauer machine has been in service with the LAFD since May, and crews have been getting accustomed to the new rig.
“Anything new is going to be met with skepticism,” Richard Fields, deputy chief of the Los Angeles City Fire Department, told Jalopnik. “Most of the skepticism that we have is kind of that uninformed assumption. It’s like, ‘how is it possibly going to work if we have an electric vehicle? It can’t run forever.’”
That’s true. The new fire truck from Rosenbauer has a limited supply of electricity in its battery packs. And that supply has to power the traction motors that move the truck as well as the water pumps and all the other essential firefighting equipment on board.
Once those batteries run down, the diesel-powered range extender kicks in automatically. The result is a truck that can meet the harsh demands of firefighting while cutting down on emissions and fuel costs. As such, it features some pretty nifty innovations in its powertrain, cab design and overall functionality.
“It’s just different,” explains Fields.
Rosenbauer International has made a name for itself creating firefighting machinery for the past 156 years. For the RTX, Rosenbauer partnered with Volvo to develop the powertrain, then set to work preparing it for the needs of fire departments around the world.
“We started a project in 2018, and that was not necessarily about creating a product for Rosenbauer,” Paul Jansson, program director for electromobility at Volvo Penta, told Jalopnik. Instead, the effort was about creating an efficient platform that could cater to Volvo Penta’s marine and industrial clients.
But then, Rosenbauer approached Volvo Penta to collaborate on a powertrain for its new hybrid firetruck. The deal tasked Volvo with creating a hybrid drivetrain that Rosenbauer could then design a new kind of truck around.
“We basically had to tailor that solution to their needs,” says Jansson. “So we took the platform and developed it specifically for Rosenbauer, because they were the first customer that we had.”
The resulting powertrain incorporates four electric motors, two battery packs and that diesel range extender. Two of the motors are for propulsion, one sitting on each axle to power the front and rear wheels, giving the RTX four-wheel-drive. A third motor powers the on-board water pump, and the fourth is connected to the range extender to generate electricity.
“The energy storage solution, or the batteries, are kind of flexible and modular. One is laying down horizontally and one is standing up. That was something that Volvo Penta had to develop to meet the needs of this very compact vehicle,” Jansson said.
That battery orientation allowed Rosenbauer to fit more shelving into the truck to store essential firefighting kit, and left space for a water tank.
“It’s ergonomically far more advanced,” Fields says of the hybrid truck. “They designed the compartments and how the tools are laid out based on the firefighter expending the least amount of energy. We don’t use a lot of compartment space on our normal engines and everything is on a flat shelf. This vehicle maximizes that space.”
The Rosenbauer truck has the same flat-front “cab-over-engine” design you’d see on most conventional fire trucks, but the absence of a huge diesel engine allows the truck to fit all the necessary firefighting equipment in a more compact footprint. This, again, improves usability for firefighters. “Because there is no engine that starts from the front, that eliminates all of that obstruction that a normal engine has,” Fields says. “Traditionally, the entire cab has been designed around the engine being up front and the transmission and all of that. Now that is gone, so you get all of that space back and you can step in and stand up like you would in a motorhome.”
Fields also cites other innovations in the truck, like the ability to raise and lower the ride height from 7” up to 19”, something not found on many traditional fire trucks.
All this means that the firefighters in LA are able to get in and get on with their jobs quickly. From the standpoint of fighting fires, there hasn’t been much adaptation required to use the truck. It’s only when it’s time to refuel that firefighters have had to switch up their routine.
The truck has a total of 132 kWh worth of battery to fill up. With a quick-charging 150-kW plug, the truck can be topped up from 50 to 80 percent in just 15 minutes. At Station 82 in LA, where the first RTX in the U.S. is based, firefighters plug the truck into a port like this and can charge a half-empty battery back to full in 30 to 45 minutes.
But not every location has such fast-charging equipment, and a top-up at a regular 120-volt power outlet would leave you with a very long wait. In an emergency situation, long waits aren’t something you want to encounter.
To avoid this, Volvo and Rosenbauer built in a diesel-powered range extender that can start up to keep the motor and pumps running when the battery level drops. This range extender takes the form of a 3.0-liter twin-turbo diesel straight-six from BMW. The B57 engine that Rosenbauer uses in the RTX is the exact same unit that BMW installs in cars such as the 540d xDrive and the 740Ld xDrive.
“As an emergency vehicle, they couldn’t say ‘we can’t put out this next fire as we have no more energy,’” Jansson said. “So, that is why we have to have the range extender in there.”
According to Rosenbauer, the range extender starts up whenever the batteries drop below 20 percent charge. The company says the diesel engine can recharge the truck in as little as 45 minutes. Depending on conditions, a fully-charged battery can keep the RTX fighting fires for four to six hours.
And while that range extender does pump out exhaust fumes when it’s running, it does so for a much shorter period of time compared to a conventional fire truck. Fields and the LAFD were able to run the truck and its pumps for “about 16 hours straight” while testing the RTX, using less than a gallon of diesel fuel in the process.
At present, Fields is hesitant to discuss the truck’s efficiency any further, as the LAFD is still getting to grips with the new machine’s capabilities. But to get an idea, we can look to Europe: Jansson has been working closely with the Berlin fire department, which has been running an RTX around the city for a couple of years now.
In the German capital, Jansson said that firefighters responded to 95 percent of emergency calls on pure electric power, which is mighty impressive.
“We are always looking for new technology and Rosenbauer is innovative and wants to have more power, more energy,” says Jansson. “One of the questions is, could we get rid of the range extender? And the answer is yes, quite simply. You could get rid of it now if you want to.”
But obviously, having the safety net of the diesel generator ensures that the truck can keep running to emergencies again and again.
That all sounds very promising for our electric future. But the LAFD’s experience with the battery-powered truck hasn’t been seamless. Shortly after entering service, the truck hit the headlines after a leak was found in one of its water tanks.
“We were very careful about the design of this vehicle as Rosenbauer are not used to the U.S. requirements, their other trucks are in Germany,” says Fields. “So they had to put different lights and different sirens on the truck. And, the way most of the hydrant systems in Europe work is different, they are not under pressure.”
This was something that was initially missed in the rollout of LA’s fire truck. American hydrants push pressurized water into a fire truck’s tanks, so LAFD crews were inadvertently over-pressurizing the water tank when they filled it.
“But little things like that are going to come while putting it through its paces,” adds Fields.
Volvo Penta and Rosenbauer had to make other changes to allow the truck to run on U.S. roads as well. The American truck uses a different charging system compared to its European counterparts, due to the higher voltage used in grids across the pond. The truck’s HVAC system also needed to be altered to run on a different refrigerant, as the compound used in America was abandoned in Europe back in 1995. Tweaks like this, Jansson says, caused “nightmares” for engineers at times.
Now that the creases are being ironed out, the LAFD is hitting the streets with the RTX. And so far, it sounds like crews have had no problem adapting to the new engine. But, Fields warns that the department won’t know for sure if the truck is a step up over its internal-combustion-powered counterparts until things start going wrong.
“It is still a machine, and it is going to break, it is going to fail,” he says.
It’s not just the performance of the vehicle being assessed by the LAFD. Fields also has to consider the maintenance and running costs of the vehicle before fully committing to a battery-powered future.
Other than the initial purchase, the largest cost of any EV comes with the battery packs. In the Rosenbauer truck, these are predicted to lose between two and five percent of their performance each year, according to Fields.
“If that stays true, then we’re looking at replacing the battery every 10 years or more,” Fields said. “Other than replacing tires and brakes, there really are no other mechanical things that we have to replace on the vehicle.”
With its current lineup of fire fighting vehicles, Fields says the average lifespan of an LAFD truck sits somewhere between 10 and 15 years. And while a new battery pack might cost a lot, Fields is sure that the new electric truck will work out better for taxpayers than its diesel-powered counterparts over the same period.
“We’re replacing all kinds of things that go wrong with a normal combustion engine,” Fields explains. “We’re replacing an entire head or a transmission — we do a lot of repairs over the life of our normal engines. So while the vehicle itself costs more, we are anticipating finding that saving in the maintenance side of it.”
And that’s good news for the other fire departments across the country that are looking to Los Angeles for guidance.
“Most fire departments in the country either copy or closely follow what LA city fire department does,” says Fields. “So people have put in orders and are looking to get one for themselves, and that is based on what LA city says about this rig.”
It’s because of this that LAFD is in constant communication with Rosenbauer to keep the truck running smoothly. And so far, Fields seems impressed. So much so that he is convinced the squad will have more EVs in its fleet soon.
“Absolutely, for sure,” he says. “We definitely will, and I will say that this innovation is going to force the rest of the industry to speed up their work.”