From SUPERAV 8X8 to VBA for the Navy

(To Gianluca Celentano)
27/07/23

In reality it's just a question of getting used to the automatic gearbox even if the right hand occasionally falls between the seats to look for the cloche and change gear. Although here with us there is a consolidated cultural and practical bond that leans towards the manual gearbox, the relationship between man and mechanical vehicle has already seen an evolution for several years. A slow but constant change of pace in favor of other technical and connection priorities, those that represent a priority and a security for the military on a mission.

The increasingly widespread diffusion of automatic transmissions which, until the last century seemed absolutely a niche product, are the first clear sign of new habits and other needs to be requested from the automotive industry.

The current variegated motion automation systems have become increasingly reliable and performing, even though they still cannot (and perhaps never) replace the technical skills and sensitivity of a professional, that is, that person who does not time performances as in Formula One , but rather seeks a total operational symbiosis with the medium. A practical example is theOff Road. In this regard, it should be remembered that Italy above all on a global level has been for a very long time with unclear ideas on automatic transmission and, even today, there is a certain embarrassment between the various types of existing systems. For this reason, in the stories I have always and briefly divided the two main families of automatic transmissions: the hydraulic and the automated.

Even military vehicles continue to renew themselves undergoing a technological evolution that simplifies some maneuvers favoring the operator's concentration on other aspects. This is the case of the 36 VBA (Amphibious Armored Vehicle) by Iveco Defense Vehicles destined for the Navy (marine brigade Saint Mark).

Here, among the alternatives, the focus was on an exceptional manufacturer in terms of transmissions: Allison Transmission.

The one between Allison and IDV is a historical and alternative link to ZF; the numbers speak for themselves about the appreciation of these transmissions which have seen supplies for the Spanish army and the Marines who, since 2018, have requested over 200 amphibious vehicles Amphibious Combat Vehicle ACV 1.1. These are highly advanced 8x8 wheeled vehicles with a transport capacity of up to 13 soldiers, built on the basis of the SUPERAV 8X8 amphibious platform (developed - formally - with BAE Systems), where the new amphibious armored car from Iveco originates.

The VBA

It is an 8x8 off-road vehicle with great versatility on the road, capable of being dropped from a ship or recovered in the open sea, guaranteeing modern anti-IED, anti-mine and ballistic protection technologies. Allison has essentially provided for the creation of an ad hoc transmission capable of interacting both for the terrestrial functions of the vehicle and of converting for those in water.

The chosen engine is the six-cylinder FPT Cursor 16 700 HP known for its extraordinary performance in missions which is combined with the 4800-speed Allison 7SPTM automatic transmission and its double transmission line to the wheels: the driveline to H.

The derivation comes from the Centaur and the VBM Arrow and on the road it allows a declared speed of 105 km/h. In the water, the hydraulic pressure affects two propellers tested to face the sea state 3 and reach 6 navigation knots.

Off road

Choosing an Allison automatic transmission on a heavy vehicle is down to the system powershifting which, according to a press release from the manufacturer, would favor driving in difficult conditions, ie those where the weight and slow shift times would cause the vehicle to sink. However, it is a torque converter system (4000 series Allison) then a clutch plumber lock up able to supply the torque simultaneously on the 8 wheels (full time) letting them work constantly with the engine.

Extreme IDV vehicles are tested to be able to overcome slopes of up to 60% uphill and downhill, they must be able to withstand extreme environmental temperatures, from the Arctic to the desert, and know how to navigate. They must be safe and upgradeable, as each vehicle can be equipped with different mission systems, so they must be modular as time evolves and scenarios change.

The Allison product

For Allison I have always highlighted the good product that has passed and satisfied all the professional test benches. Suffice it to say that, for over a century, it has been a supplier of transmission systems for United States Army vehicles and industrial and agricultural vehicles as well as civilian quarry vehicles. Robustness and hydraulic engineering are the prerogatives of her success.

Photo: US Marine Corps / IDV / Allison