The three-pointed star leader of the tacticians? Compared to the resources of the Bundeswehr

(To Gianluca Celentano)
28/11/19

They are born as a military variant of the rich civil production, a custom where the heavy-handed Mercedes don't need too many presentations. If we listen to the veterans of the steering wheel, the truck drivers but also the bus drivers, when we talk about "Three-pointed Star", the judgment on the mark is almost unanimous: "they are the best".

A figure also confirmed by the sales of the German brand in the military sector, where both heavy vehicles or some of their details - for example components, engines and to some extent MTU - are attributable to the Stuttgart brand and are substantially present in all the armed forces of the world.

What does it mean to be the best?

They are the ones that give less trouble: despite a perceptible higher initial cost, they subsequently offer a good maintenance of the value - like all the Germans - and a quality that is appreciated over time. Although the addition of electronics in detail - control units - has in some cases also brought them to their knees it is also true that the positive trend of Mercedes has never diminished since the beginning of its debut in the dawn of the last century.

The civil and military user seems to have understood that some anomalies, most often not specifically mechanical, are not due to the refined engineering, but more probably to the massive introduction of mechatronics.

The engines, today all Euro 5 and 6, bodies and subgroups for example, are maniacally tested in all the most demanding operating conditions, where a minimum uncertainty equates to repetition of the test or to the rejection of the engine or model. The Germans are not joking and the results are tangible.

If there is no economic difference in quality between an A-Class and an S-Class in the automotive sector of the Stuttgart-based company, then there are other aspects that need to be taken into consideration. It would seem that the launch of the Mercedes vehicles in the military takes place later than the civilian one. An extra guarantee to exonerate any doubts about the reliability of the vehicle on the battlefield.

You will have understood in the light of so much selective severity, how this production is both bivalent, whether it is for civil use or for the defense line. We could argue that nothing is left to chance, not even a light, an indicator or a bolt. Grounded concepts that translate militarily and based on the class of the vehicle, into a perceptible intuitive simplicity of the controls, great versatility and reliability to which the unmistakable distinctive lines of the Mercedes-Benz brand are associated.

The comunication

Another strong point of the Mercedes brand is the availability of its governance and assistance network in providing information and technical data on military production not covered by secrecy. In fact, interaction with the media or fans of the sector is always taken care of as it is considered positive and even stimulating; Also interesting is the web and video promotion that the Stuttgart-based company considers essential to make its vehicles known.

Curiosity: I give you a detail that is really hard to find online. As you know, the engines also have a serial alphanumeric identification code; Mercedes, associated with the numbers, uses the abbreviations OM as a historical abbreviation for Öl Motor Mercedes, an oil engine.

Optimization or increased spending on defense?

The media line rotated on rubber without a hull of the Bundeswehr appears at least repetitive, that is, less optimized than ours. In fact, the heavy tactical and logistic activities are essentially made up of three types of models, ARCOS, ATEGO, ZETROS, the latter with a fairly retro line and advanced engine, "a medium snout" where, among other things, doubts about maneuverability and anti IED armor capacity are not few.

Here are the variants of a single ASTRA model to provide a suitable means both for ordinary logistic tasks, tactical ones, and operated tactical ones to which is added the TRAKKER derivation.

The complete German range is represented by seven types of vehicles rotated against our four if we exclude the multiruote with armored and / or armored hulls, Centauro, Freccia and the SuperAV variant.

At the end of the German defense park there are also some "light" like the UNIMOG, with extremely interesting features that can be associated as typology, to the historic VM90, today MUV 70.20.

AROCS tractor and road tractor

I will not go too far into the technician on this super truck, but some considerations and impressions are interesting.

The AROCS platform, making its debut in the 2013 in the civil field and for some time has been included in the military range of Mercedes-Benz Defense Vehicles, in a space previously occupied by the historic ACTROS.

It is a four-wheel drive vehicle with two, three and four axles, designed for heavy and heavy construction tasks, with a versatility of use even for long journeys. In short, an operational means made for the hard work of the Bundeswehr.

Reinforced frames with single or twin wheels, leaf springs and rear cradle, and with various traction patterns are configured in four types based on use. The heavy tractors "Road tractors" for towing heavy trailers, tanks, etc., heavy-duty, roll-off tops also used as a bridge-laying wagon, crane, etc., i medium-duty, for limited freight transport light-duty, the softer version for the daily departmental tasks. The AROCS variants can be crossed between our Trakker and ACTL, but above all to the toughest ASTRA SM the Heavy Duty.
How they are made
They all have an 6 turbocharged diesel-in-line cylinder engine and the powers start at 238 up to 625 horses, the latter with a torque delivery capacity of 3,000 Nm.
I know, the data can be confusing if we compare it to the cavalry of the SCANIA 8V Series R from 16,4 liters with 730 horses and 3500 Nm, but some factors must be taken into consideration when talking about an effort.

While I try to make a comparison on power, I realize more and more that in the field of heavy vehicles the displacement is often an unpublished datum, although it is not a superfluous value.

Years ago during a parenthesis with the buses, I was driving an Iveco Stralis articulated lorry by 560 and I can support, apart from the usual spies that lit up without reason, which is a large machine with which I transported loads even at the mass limit. Then one day a colleague lent me his analogue from 480 horses and I can confirm that it was even brighter, even on load.

In the case of AROCS Heavy Tractors, torque and power delivery comes from a displacement that should reach 12,8 liters, against, just to make a comparison, the 16.4 liters of the King of Scania trucks.

The intersection of these values, the gear ratios but also the containment of the throttle volume and the type of injection are mainly the data that make the difference when you want to develop power on the road and off-road torque.

More versions and "light", too of Arocs have the same engine but with a displacement that should start from 7,7 cc.

Cinematic chain, PowerShift 3

I would like to highlight a detail of AROCS: its innovative transmission. With a range, based on the use of 16 reports, it offers different driving programs set by the driver or set by its detectors.

Il PowerShift 3 it is not a double clutch, but a revolutionary robotic single disc - which can also be used manually - to which an optional is added turbo retarder, a solution that at first left me some doubts about reliability in the military sphere, compared to the most common automatics with torque converter.

If in the professional use the automatisms are advantageous for the driver, it is also true - and I underline it - that from the military workshops there is often a complaint against a stop for electronic problems also due to the tactical use. Always guilty of "improper use" by the military?

The scheme PowerShif t3 with the addition of turbo retarder, reminds us of our semi automatic ATC81, but it is only a technical reference to make people understand what it is. There is a traditional clutch but only two pedals, brake and accelerator.

The classic is placed along the main gearbox shaft retarder (in this case inserted in the gearbox bell and not placed on the transmission). The retarder it takes the form of a hydrodynamic coupling (not torque converter) and, in the case of maximum loads, the first start from standstill or uphill occurs due to the spiral vortex generated with hydraulic speed and pressure. After that, the circuit expels the pressure and the gearbox becomes an advanced robot where there is a physiological expectation (chosen by the software) for the changes (it is a single disc) to which however the enormous torque of the propeller compensates. Instead, during the slowdowns or the descents, in autonomy or commanded by the conductor, the turbo retarder it comes back under pressure slowing down the vehicle in synergy with the engine brake. This is also generated when we set a self-limited speed and face a descent.

It is also possible the characteristic sliding at minimum for the maneuvers, thanks to the effect of hydrodynamics and not for the rubbing of the clutch when the "electro hospital of the brake" is raised. A solution that preserves all the kinematic components that are really put to the test on AROCS.

One wonders on the basis of such refinement, what are the maintenance costs but we are in the hands of Mercedes and, at least in the civil sphere, the classic 16 manual is available. Consider that the Stuttgart brand associates with the most powerful heavy tractor, work skills in the order of 250 tons.

On board the interior should not deviate too much from the civil series - a Mercedes characteristic - and electronics are presumed to be limited compared to the civil or otherwise well hidden series; interesting are the six seats for the soldiers in the cabin, the space for a team in essence.

As for ACTROS, we expect soon to be able to also talk about the armored version, which will certainly not have the protection features of the GFF4 Krauss-Maffei Wegmann Grizzly, the specialized anti IED.

Then there are the logistic, some superfluous?

ZETROS is represented by substantially off-road chassis with a Ptt that starts from the 10 tons and arrives at 36. Two or three axles, 4x4 and 6x6 or 4x2, in truck or road tractor conformation to be used substantially for field logistics.

They are half-muzzles - "means", in the sense that they have a limited front volume compared to the USA or Iveco 330.30 trucks - and with an unmistakable colonial line.

They have a six-cylinder in-line but with 510 horses and should have a displacement of 7,7 liters, these are the power and displacement variants of the OM 926 engine, a bit like the series Cursor.

Two types of transmission are available, a standard nine-speed gearbox with G 131-9 hydraulic control (eight forward gears + crawler) with high gear with direct transmission and, optional, an Allison 3000 SP / PR six-speed automatic. It is a versatile vehicle but the two front volumes are paid in terms of maneuverability, even if with smaller dimensions than Arocs.

It is associated with the described muzzle, a more traditional truck, the ATEGO (photo) and, just to make a comparison, type and characteristics cross more or less with our euro Cargo, banned by us from operational use but present as a tactical mobility solution for other defenses.

Let's not forget that euro Cargo it is an evolution of ACM80 and part of it has been inserted between lights and shadows also in the very rare MMW1 4x4. It also has a six-cylinder but with 156 horses and manual gearbox up to nine gears.

UNIMOG is the winner as well as in the top ten plus ultra of the hard off road. Also known to us in the civil field, Vff, Pc, rescue is very appreciated for the wide angles of off-road vehicles, wheelbase and reliability, in short for 4x4 fans a true work of art in the round.

At the conclusion of the Bundeswehr's fleet there is a van Sprinter van also available in 4x4 and then the queen of the most refined 4x4, the jeep G Class. Maybe an idea for replacing our AR90, where for now the Wrangler is waiting and Land Rover continues to dominate the terrain of reconnaissance cars.

Photo: Bundeswehr / Mercedes-Benz Defense Vehicles / web