Truck & Off-Highway Engineering - October 2024 - 9

TECHNICAL INNOVATIONS
PROPULSION
Mercedes: H2-ICE is a viable path for commercial trucks
Mercedes-Benz has unveiled a pair of prototypes
powered by hydrogen combustion
engines that were created in collaboration
with Mörtlbauer Baumaschinen
Vertriebs. The prototypes are part of the
" WaVe " development project to research
hydrogen combustion engines for special-purpose
vehicles.
The WaVe project is a publicly funded
program by Germany's Federal Ministry
for Economic Affairs and Climate
Action. It consists of 18 partners ranging
from industry and science experts and
began in July 2021. Development work
on the prototypes began in mid-2022.
The main objective of the WaVe project
was to develop a hydrogen-based drive
system for working machines that demonstrated
the practicality of replacing
diesel-fueled trucks.
Currently both vehicles are being
tested in the field to verify driving and
refueling operations. The drive system
has been in use for over a year in the
Unimog implement carrier. The
Mörtlbauer crawler dumper was put
into operation in spring 2024. They
were tested at the Mörtlbauer factory in
Fürstenzell, Bavaria.
" After numerous test deployments,
emission measurements and technical
fine-tuning, we are convinced that hyThe
Unimog implement carrier and Mörtlbauer crawler dumper are equipped with medium-duty
engines converted for hydrogen propulsion by employing specialized pistons, an H2
-compatible
intake system and an optimized ignition system.
drogen combustion for work machines
with high power requirements, both for
driving and for powering auxiliary
drives, is worthwhile, practical and very
low in emissions, " said Franziska
Cusumano, head of Mercedes-Benz
Special Trucks.
Armin Mörtlbauer, managing director
of Mörtlbauer, said in a statement: " The
fact that our crawler and the MercedesBenz
Special Trucks Unimog can be
easily refueled with gaseous hydrogen
and that these vehicles also work reliably
when using implements is the result
of the outstanding cooperation in
this research partnership ... However, to
apply these in series production, we
have to go even further on this path. If
the government and society choose to
follow the path toward hydrogen combustion
engines, we are ready to go. "
The converted Unimog U 430 implement
carrier transported the crawler on
a low loader to the Mörtlbauer factory.
Developers reportedly demonstrated
the refueling process at a mobile hydrogen
refueling station as well as implement
operation with a front-mounted
sweeper from Schmidt.
Tests were also conducted to ensure
the viability of the PTO system while
driving. These systems require sustained
high-power output, which
Mercedes states the hydrogen combustion
engine is well-suited for. The
Unimog and crawler are equipped with
medium-duty engines that were converted
for hydrogen propulsion. This
conversion included specialized pistons,
a hydrogen-compatible intake system
and an optimized ignition system.
The Unimog was equipped with four
The Unimog specialty vehicle was operated with several different attachments to demonstrate all
potential use cases.
TRUCK & OFF-HIGHWAY ENGINEERING
TÜV-certified, 700-bar (10,152-psi) highpressure
tanks that hold roughly 13 kg
(28.6 lb) of gaseous hydrogen in total.
The engine delivers around 290 hp (216
kW) and was operated with several different
attachments to demonstrate all
potential use cases. The crawler dumper's
engine had a similar output and a
slightly higher hydrogen capacity.
Matt Wolfe
October 2024 9
BOTH IMAGES: MERCEDES-BENZ

Truck & Off-Highway Engineering - October 2024

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