[Asif 6959]

Originally Posted by ajman28

Has this model already been launched?
I have never seen a truck with a lift-axle system on the last axle (as shown in the pic)! Isn't the lift-axle system only adopted to the middle axles?

Yes Sir, already been showcased at the 2012 AutoExpo, Delhi
Source : Click here

[ajman28]

Originally Posted by Asif 6959

Yes Sir, already been showcased at the 2012 AutoExpo, Delhi
Source : Click here

Thanks, but the article doesn't say much about the lift-axle. All it says is:
"a twin drive axle and a tag-lift axle at the rear. "

Do you know which axle in the rear is being lifted?

[Ashley2]

Originally Posted by ajman28

Thanks, but the article doesn't say much about the lift-axle. All it says is:
"a twin drive axle and a tag-lift axle at the rear. "

Do you know which axle in the rear is being lifted?

Rear most axle RA3 is liftable in this case.

[Asif 6959]

Originally Posted by ajman28

I have never seen a truck with a lift-axle system on the last axle (as shown in the pic)! Isn't the lift-axle system only adopted to the middle axles?

I guess the lift-axle on the rear is a thing of the past and are hardly seen these days on any international trucks. In this case as mentioned in the article this is to increase the payload,since trucks in India are classified based on the load each axle carries (axle configuration - see here).I might be wrong here, but feel that's the reason why a rear lift-axle is used.

The increased payload will make this vehicle ideal for the movement of goods like cement and steel coils. This will translate into better returns for transporters and could potentially drive down the transportation costs of core goods such as steel and cement.

[ajman28]

Originally Posted by Asif 6959

I guess the lift-axle on the rear is a thing of the past and are hardly seen these days on any international trucks. In this case as mentioned in the article this is to increase the payload,since trucks in India are classified based on the load each axle carries (axle configuration - see here).I might be wrong here, but feel that's the reason why a rear lift-axle is used.

The number of axles increase the payload capacity but a "lift-axle" system is used not for increasing the payload but to increase the tyre mileage for the user. When the truck is not in a loaded condition, the axles with this facility are lifted so that they are not in contact with the road; hence better tyre mileage.

I was confused in this case because I had never come across a system where the rear-most axle is lifted.

[Asif 6959]

^^^Agree with your point Sir, but in that case it would have made more sense to have the lift axle in the middle, as its usually seen. But in this case on the LPT 3723,the truck can carry 4T more than the existing 31T MAV segment.So i feel the lift axle is at the rear and not in the middle.

[Raag Sandhu]

The TATA looks like it got done in a hurry. The thing is too long to venture off road with its puny 520 horsepower, the CTIS looks like it got fitted in a local garage, the axles do not look too promising in terms of articulation, ets. The TATRA has everything going for it, after all I have seen it hauling 42 tonnes woth of a fully equipped battle ready T72 across the most challengig off road conditions. The T813 is a torque monster and I have seen it doing pulling insane load pulling with relative ease, its not a truck, its a piece of art!

[kar_meh]

Originally Posted by pratheekkunder

I was on my way to Pune for the Indian Superbike Festival 2012.Took a tea break at the start of the Dehu Road. While having a cup of some nice tea, i saw this massive truck with On Test sticker coming my way.I quickly asked a friend to clicks few pictures.
It was a Tata truck. I think its an All Wheel drive, not sure here.May be a new truck for Indian Military.
The truck was fully loaded with Tyres and lots of heavy goods.
All i can say is, the truck looked massive.The driver had a very difficult time taking a U Turn. Took him almost 5 mins.

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The Truck in consideration is an Army Truck LPA3138 (8X8). Its powered with Cummins 380 HP ISLE Engine. Was showcased at the recent Defense Expo in Delhi.

[kar_meh]

Originally Posted by Asif 6959

^^^Agree with your point Sir, but in that case it would have made more sense to have the lift axle in the middle, as its usually seen. But in this case on the LPT 3723,the truck can carry 4T more than the existing 31T MAV segment.So i feel the lift axle is at the rear and not in the middle.

To understand the mechanism we need to understand the type of Axles:

1) Tag Axle - A dead Axle situated behind the Drive Axle.
2) Pusher Axle - A dead axle located immediately in front of a drive axle.

In a 37T vehicle there are two options for fitting the axle.The vehicle can be fitted with "Tag" Axle as in the case of Tata 3723 or "Pusher" Axle (like in Tata 3118).

"Tag" or "Pusher" Axles can be Fixed or Lift depending upon the Product Design.

Tata is providing "Lift Axle" in 31T & 37T which is outsourced from Hendrickson.

Tag Axle has few advantages over Pusher Axle:-

1) Tag Lift Axle gives 150mm-180mm ground clearance as there is no propeller shaft to restrict its lift. In Pusher lift Axle, "lift" gets restricted to 120 mm.

2) Turning radius of vehicle is reduced considerably by using a "Tag Axle". Since both Tag & Pusher axles are self steered Pusher Axle being in front has more turning angle hence larger turning radius.

3) Having a Tag Axle gives you choice of having multiple wheelbases (Hence choice of different Cargo Deck Length) of the vehicle as it eliminates major redesigning of the vehicle.

4) Weight get evenly distributed when the Tag Axle is lifted as compared to the Pusher Axle which put extra Load on Drive Axles when in Lift Position.

Tata 3723 is fitted with anti theft feature by which the "Tag Axle" if in lift position comes down automatically when the engine is turned off. This is to prevent theft of Tyres which can be easily removed when in lift position.

Also the moment vehicle is put in reverse gear the lift axle is raised automatically to prevent dragging of Tyre while reversing.

[SAE40 in veins]

Originally Posted by Raag Sandhu

The TATA looks like it got done in a hurry. The thing is too long to venture off road with its puny 520 horsepower,

Just to put the facts straight, the comparable TATRA available with the Indian forces is fitted with the Cummins ISMe 440 HP BS II engine and the BS III versions have a 420 HP engine while the TATA 12x12 is fitted with a Cummins ISXe 15 liter powerpack with 520 HP on tap. As it stands, Tata has a 100 HP advantage in the 12x12 space. As far as TATRA is concerned, it is the unique back bone suspension set up which makes it a superior machinery off road and not engine power.

[Ashley2]

Originally Posted by kar_meh

....
4) Weight get evenly distributed when the Tag Axle is lifted as compared to the Pusher Axle which put extra Load on Drive Axles when in Lift Position.
.

There will be definitely additional load on rear axle if the tag or pusher is lifted and there will be no much of difference between them IMHO.

[kar_meh]

Originally Posted by Ashley2

There will be definitely additional load on rear axle if the tag or pusher is lifted and there will be no much of difference between them IMHO.

I do agree with you. I am using the comparative term for weight distribution. When "Tag Axle" will be lifted weight distribution will be much even than using a Pusher Axle.

[Raag Sandhu]

Originally Posted by SAE40 in veins

Just to put the facts straight, the comparable TATRA available with the Indian forces is fitted with the Cummins ISMe 440 HP BS II engine and the BS III versions have a 420 HP engine while the TATA 12x12 is fitted with a Cummins ISXe 15 liter powerpack with 520 HP on tap. As it stands, Tata has a 100 HP advantage in the 12x12 space. As far as TATRA is concerned, it is the unique back bone suspension set up which makes it a superior machinery off road and not engine power.

The TATRAs originally had roughly 270 hp at hand but what them stand out of the crowd was a beautiful combination of high torque modular engines, with solid drivetrain components encased in a highly efficient backbone chassis. Even if the TATA all wheel drive truck has 1000hp it will never be an effective off road machine. TATA needs to at least offer portal axles to make the deal sweeter, else the usual live axles are as good as fossils.

[torquecurve]

Tatras have lower torque/wt ratio compared to the Tata/AL's.

Though the Tatras' have better 'Live' suspension, it does not necessarily make them better offroaders. In certain situations The Tata 12X12 can provide better support in Operations which require tow/high gradability.

What is also important is servicability. This is an aspect where the Tata's/ AL's score better due to a lower logistic footprint, commonality of parts in commercial/military applications.

For Military vehicles ' Extreme Offroading' is not the most important criteria. What matters though is "Rough Roading" and pulling power/efficiency. ALso important (highly important) is having a logistical tail which is as short as possible.

[Autokrat]

Originally Posted by W.A.G.7

The fit and finish as well as the build quality look questionable though. The front end looks especially crude.

To me it appears the question on the build quality arose due to the crude looks of the cab. Majority of the military vehicles being low volume tend to have fabricated cabs unlike the mass produced variety seen on commercial trucks. This in no way diminishes its quality or utility.