VOLK Hybrid Tow Tractors HFZ 20 N - VOLK Fahrzeugbau GmbH

innovation@work ®
HFZ 20 N
HFZ 30 N
Hybrid Tow Tractors
Towing capacity 20 – 30 t
Fahrzeugbau GmbH

Hybrid Tow Tractors
Your problem
Whenever operating conditions require use in closed buildings as well as mastering
comparably large distances outdoors, pure diesel or electric tow tractors prove to be
inadequate: while diesel tow tractors are excellently suited for covering great distances
outdoors, they can be used only very limitedly in closed buildings because of the
emissions. Electric tow tractors on the other hand are suitable for use in closed spaces
but not for use on spacious airport grounds or company compounds due to their limited
battery capacity.
Fahrzeugbau GmbH

Our solution
The VOLK Hybrid Tow Tractors HFZ
20 N – HFZ 30 N are equipped with
an electric motor as well as a diesel
engine. Therefore they can be used
both in closed spaces and outdoors.
The diesel drive can be switched on or
off without any jerks and without
interrupting traction – regardless of
the speed and driving direction. This is
possible because the driving axle is
always driven by the electric motor.
When the diesel engine is switched on,
a generator driven by this diesel
engine generates the current required
for the electric motor. Excess power
is used to recharge the traction
batteries. After the diesel engine is
shut off, the required current is taken
from the traction batteries.

Lower life cycle costs
The acquisition costs of investment goods typically make out only a fraction of the total
life cycle costs. Therefore, not only the initial purchase price but also the later operating
costs, useful life and resale value play an important role in investment decisions. Balance
sheet policies must also be considered when developing investment projects. Given
this, one of our basic objectives is to minimize the life cycle costs of our vehicles and to
offer our customers not only vehicle purchasing but also tailor-made leasing models.
Fahrzeugbau GmbH

Lower operating costs thanks to
higher efficiency
Thanks to the design principle of the
VOLK Hybrid Tow Tractors HFZ 20 N
– HFZ 30 N, the diesel engine always
runs in a defined r.p.m range independent
of speed and hauled load,
thus developing a consistently high
efficiency. Reduced wear and distinctly
lower fuel consumption are the
Longer useful life and higher
resale value
The VOLK Hybrid Tow Tractors HFZ
20 N – HFZ 30 N are optimally
protected against corrosion: Not only
are the vehicle frames fully zincdipped
serially but they also feature a
solid, cavity-free design. Thus, corrosion
through moisture penetrating
the frame is almost impossible. As a
result. The latter is especially true
because also efficiency losses due
to hydrostatic drive components can
be avoided thanks to the design.
Therefore, a significantly smaller
diesel motor is sufficient to realize
the required traction capacity.
result, the useful life is noticeably
increased and the resale value is
higher. The same purpose is served
by the standard electrolyte circulation:
it decreases the load of the
electrodes through reduced gasing,
which in turn prolongs the useful life
of the battery considerably.

Higher availability
Because tow tractors on airports and in industrial facilities are frequently used in
continuous multi-shift operation seven days a week, maintenance and repair jobs usually
cannot be postponed to non-productive or idle machine times. Therefore they almost
inevitably result in an outage of the vehicles which is always connected with high costs
and can be bridged only by the provision of replacement vehicles in some cases. Thus one
of our priority development objectives is to increase vehicle availability.
Fahrzeugbau GmbH

Fewer downtimes thanks to the
rapid change diesel engine/generator module
The VOLK Hybrid Tow Tractors HFZ
20 N – HFZ 30 N are serially equipped
with a patented rapid change diesel
engine/generator module, the socalled
VOLK POWER PACK ® . Unlike
conventional hybrid tow tractors,
these tow tractors have a diesel engine
that is not permanently installed in
the vehicle but is part of a modular
unit. This unit can be exchanged very
easily in about 5 minutes. Because
the VOLK POWER PACK ® also has an
integrated tank, a starter battery
and a starter, it can be operated
Less maintenance required thanks to
three-phase technology and Aquamatic
The VOLK Hybrid Tow Tractors HFZ
20 N – HFZ 30 N are serially
equipped with modern three-phase
asynchronous motors. Unlike
conventional direct current motors,
these motors contain hardly any wear
parts, such as carbon brushes, and
are therefore practically maintenancefree.
To minimize battery maintenance
costs, the VOLK Hybrid Tow Tractors
HFZ 20 N – HFZ 30 N are equipped
Shorter downtimes thanks to
practically unlimited range
The VOLK Hybrid Tow Tractors HFZ
20 N – HFZ 30 N are equipped with
a very powerful three-phase generator.
With a power output of 20 KW, this
generator continuously provides more
power than is consumed by the
vehicle’s drive motor and accessories –
autonomously. Therefore all
conventional maintenance jobs on the
diesel engine can be performed
independently from the vehicle. For
this reason the VOLK Hybrid Tow
Tractors HFZ 20 N – HFZ 30 N can be
operated even during this work. For
example, one of our customers has a
fleet of 70 VOLK Hybrid Tow Tractors
for which they have two additional
VOLK POWER PACK ® modules. This
way a spare unit is always available
to prevent downtimes due to
maintenance.
with an Aquamatic system. This is a
central water refilling system which
enables quick and easy refilling of all
battery cells to the correct fill level. To
ensure that water refilling is not
forgotten in the hectic pace of daily
business, the vehicles are equipped
with an electronic electrolyte level
indicator which dependably warns the
driver and the service personnel when
the electrolyte level gets critical.
except for temporary load peaks. As a
result, the generously dimensioned
80 V/320 Ah traction batteries can be
easily recharged during diesel operation.
External battery charging is
usually not necessary.

Higher future proofness
Today, the general economic conditions are characterized more than ever by high
dynamics and frequent, often discontinuous changes. Apart from pure profitability
considerations, the aspect of future proofness is increasingly gaining importance
particularly for long-term investments. For this reason, one of our central development
objectives is to increase the future proofness of your investments through the modular
design of our products.
Fahrzeugbau GmbH

Strategic flexibility and future-orientedness thanks
to modular design
The modular design of the VOLK Hybrid
Tow Tractors HFZ 20 N – HFZ 30 N
makes them future-oriented and highly
flexible tractive vehicles: for example it is
very easy to upgrade vehicles initially
purchased as pure electric tow tractors
easily into hybrid tow tractors when
operating conditions have changed.
Conversely, of course, VOLK Hybrid Tow
Tractors can be effortlessly “downgraded“
to simple electric tow tractors.
Thus our products provide you with a
high degree of strategic flexibility enabling
you to react optimally to changed
operating conditions.

Technical Drawings HFZ 20 N – HFZ 30 N
1.295
Side view
985
Turning radius Front view
3.464
2.866
2.888
3.042
1.560 442
552
1.078
Fahrzeugbau GmbH
140
1.970
840
420
1.055
1.250
290
780
1.520

Technical Data HFZ 20 N – HFZ 30 N
Performance HFZ 20 N HFZ 30 N
Towing capacity rated load in industrial applications (BGV D 27) 20.000 kg 30.000 kg
rated load on airports (BGV C 10) 8.600 kg
Load capacity rated load 500 kg
Rated drawbar pull 3.200 N 5.700 N
Max. drawbar pull 11.500 N 14.500 N
Travel speed with 20.000 kg resp. 30.000 kg towed load 5 km/h 8 km/h
Drive/Electric System
with 8.600 kg towed load 13 km/h 13 km/h
without load 28 km/h 23 km/h
Diesel engine type Hatz
power rating 25 KW
displacement 1.716 ccm
Generator power rating 20 KW (AC) 20 KW (AC)
Electric motor power rating 12 KW (AC) 14 KW (AC)
Gears transmission ratio i = 20 i = 24.4
Battery voltage/capacity 80 V / 320 Ah
Dimensions/Weights
Length 3.042 mm
Width 1.250 mm
Height 2.070 mm
Seat height 985 mm
Loading area length 780 mm
width 1.230 mm
Loading height without load 780 mm
Ground clearance center of wheelbase 140 mm
Turning radius outside 3.464 mm
Vehicle weight with battery and VOLK POWER PACK ® 3.300 kg 3.500 kg
Battery weight 900 kg
VOLK POWER PACK ® weight 700 kg
Chassis
Tires front dimensions 195/70 R 15
rear dimensions 195/70 R 15
Wheel base 1.560 mm
Track width front 1.055 mm
rear 1.055 mm
Steering hydraulic power steering
Service brake type
hydraulic double-circuit brake system,
front and rear axle: disk brakes
number of braked wheels 4
Parking brake automatic parking brake
Suspension front independent suspension with coil spring
rear leaf springs

innovation@work ®
Fahrzeugbau GmbH
VOLK Fahrzeugbau GmbH
Stahlstraße 15
88339 Bad Waldsee/Germany
Tel: +49 7524/9709-0
Fax: +49 7524/9709-40
eMail: info@volk.de
Website: www.volk.de
No responsibility is taken for the correctness of this information. Errors excepted. Subject to change without notice. Some of the displayed vehicles are fitted with optional extras.