[Ashley2]

Originally Posted by Transsenger

Spotted the Tata 5 axle truck for the first time in Kerala. It had a long chassis with huge front overhang. The lift axle were placed at the rear end after the drive axles. The front axles / hubs, wheel rim etc seems to be derived from Novus!

Is that 3723 - 6x2 or 6x4?. What is the difference between regular hubs and the one from Novus?

[tharian]

Originally Posted by Transsenger

Spotted the Tata 5 axle truck for the first time in Kerala. It had a long chassis with huge front overhang. The lift axle were placed at the rear end after the drive axles. The front axles / hubs, wheel rim etc seems to be derived from Novus!

This dude looks good compared to the Leyland.

If you compare the snap I posted on Post 5, this one is longer although the first axle of the rear set is in the center of the bulk cement carrier structure on both the trucks.
The gap between the front set and rear set of axles is more on the TATA.
Waiting to see the other 5 axles trucks from other manufacturers now.

Regards

[Ashley2]

Originally Posted by tharian

...
If you compare the snap I posted on Post 5, this one is longer although the first axle of the rear set is in the center of the bulk cement carrier structure on both the trucks.
The gap between the front set and rear set of axles is more on the TATA.
...

Overall length of both these trucks are almost same in the range of 11m (AL at 11.4m). Note closely that AL has a larger ROH as it can accomodate spare wheel, as aganist the wheel base mounting in Tata.

[tharian]

Spotted the 3118 8x2 truck from AL that has a similar set up to the TATA 8x2.
Haven't seen much of these compared to the 2 axle front and back which are quite common from AL.

[silversteed]

Originally Posted by tharian

Spotted the 3118 8x2 truck from AL that has a similar set up to the TATA 8x2.
Haven't seen much of these compared to the 2 axle front and back which are quite common from AL.

This is a 3116il Super, one of the many 31T trucks on offer from AL. Not sure if the 3118 from AL is available with lift-axle

[Rahul Rao]

Originally Posted by hubolt

what is the price difference between a 37 tonner rigid and an 40 T tractor + trailer ? Is it cheaper ?

Tax is the real reasons why rigids are preferred over trailers. Few countries have rigids with two steered axles and three fixed rear axles with 4 tires each. In India a axle with two single tires is allowed 6 tons, while with double tires it is allowed 10.2 tons, a tandem set of axles with double tires is allowed 19 tons. But a tandem set of three fixed axles with 4 tires each is allowed only 25 tons. A rear combo of two tandem rear axles and a free steered axle with single tires is also cleared for 25 tons, so in effect two less tires for same allowed load.

GVW of trailers is easy to calculate. A 6 tire horse 16.2 Ton + single axle trailer 10.2 tons. Total 25.4 tons. A 6 tire horse 16.2 Ton + double axle trailer 19 tons. Total 35 tons. A 6 tire horse 16.2 Ton + triple axle trailer 25 tons. Total 41 tons. A 10 tire horse 25 Ton + double axle trailer 19 tons. Total 44 tons. (Haven't seen this combo)A 10 tire horse 25 Ton + triple axle trailer 25 tons. Total 50 tons.

Originally Posted by tharian

Spotted another 5 axle, this time.................
All the ones I have seen have their lift axle lifted with or without load.

The retractable axle comes down when gross load exceeds 31 tons, it can also be retracted while reversing, and in 1st and 2nd gear to increase load on driven axle and reduce chance of wheel slip.

Rahul

[tharian]

Originally Posted by silversteed

This is a 3116il Super, one of the many 31T trucks on offer from AL. Not sure if the 3118 from AL is available with lift-axle

This is the one seen more often, without the lift axle . The one in the picture earlier had 3118l painted on the cab roof, and was the first one I spotted. Does it have a lift axle?

[tharian]

Originally Posted by Rahul Rao

The retractable axle comes down when gross load exceeds 31 tons, it can also be retracted while reversing, and in 1st and 2nd gear to increase load on driven axle and reduce chance of wheel slip.

Rahul

Is the lift axle automated that it's engaged only when a weight limit is reached?
I have seen over loaded tata 3118's with the axle lifted and wondered why it's not engaged and most of the times the tires are badly worn on these axles as well. It's like a spare tire holder.

[Rahul Rao]

@tharian
What I said happens when the lift axle is set on auto. You have a manual control option to the pneumatic lift mechanism too. it is necessary to lift it while reversing. Then again when you are facing wheel slip on a gradient lifting it increaseing weight on driven axle(s) helps, and easiest way to do it is retract this axle.
Those who keep it retracted on bad roads damage the tyres on it,as they keep hitting stones and other obstacles. The retracted tyres also hit large speed breakers.

Rahul

[silversteed]

Originally Posted by tharian

This is the one seen more often, without the lift axle . The one in the picture earlier had 3118l painted on the cab roof, and was the first one I spotted. Does it have a lift axle?

Apologies. There's only a 3118il Super, with the lift axle. There's no 3116il with the lift axle.

The truck in the pic in your quoted post does not have a lift-axle, but both the front axles are steerable.

Originally Posted by tharian

Is the lift axle automated that it's engaged only when a weight limit is reached?
I have seen over loaded tata 3118's with the axle lifted and wondered why it's not engaged and most of the times the tires are badly worn on these axles as well. It's like a spare tire holder.

Many TM 3118c trucks had the lift axle mechanism damaged, and what you saw were such trucks. probably. There's also a way to override the automatic system and lift the axle to improve traction, as Rahul Rao mentioned, those trucks could also belong to this category. The pusher tag axle though reduces tyre wear in theory, while returning empty, the additional wear caused by the uncontrolled movement, when the additional axle is pushed down, is considerable.

Originally Posted by Rahul Rao

A 6 tire horse 16.2 Ton + triple axle trailer 25 tons. Total 41 tons. A 10 tire horse 25 Ton + double axle trailer 19 tons. Total 44 tons. (Haven't seen this combo)A 10 tire horse 25 Ton + triple axle trailer 25 tons. Total 50 tons.

I've never seen any tractors rated for 41T, 44T or 50T. But there are 40T and 49T rated tractor-trailer combos. Are there some exceptions when it comes to trailers?

[Rahul Rao]

Originally Posted by silversteed

I've never seen any tractors rated for 41T, 44T or 50T. But there are 40T and 49T rated tractor-trailer combos. Are there some exceptions when it comes to trailers?

Tata 4021 actually gets an RTO passing for 41 tons gross it is a 6 tyre horse with 3 axle trailer.

Rahul

[Ashley2]

Originally Posted by tharian

Spotted the 3118 8x2 truck from AL that has a similar set up to the TATA 8x2.
Haven't seen much of these compared to the 2 axle front and back which are quite common from AL.

This is the recently launched 3118il Super with lift axle, targeted specific one side applications like bulker, container transport, tipler. This was launched to consolidate the various options available in 31T. But the downside in lift axle is you will need to settle down with limited WB. Further, WB limitation means limitation on loading span as well.

[Rahul Rao]

@silversteed.
You are correct. The maximum capacity of set of three tandem unsteered axles has been reduced to 24 tons about 4 years ago, so the GVW has come down by 1 Ton.
@Ashley2
Has any one tried to have lift axles with double tyres. I have seen flat bed trailers with a crude lift mechanism, where the wheels are jacked up, and a pin placed below the leaf spring which is held by bush at one side and free sliding at other.
Also are three axle bus chassis planned by AL or Tata. As per MV rules two axle buses are restricted to 12 M, but three axle ones are allowed 15M.

Rahul

[silversteed]

Originally Posted by Ashley2

...the downside in lift axle is you will need to settle down with limited WB. Further, WB limitation means limitation on loading span as well.

Two questions:
1. Why isn't the lift-axle fitted ahead of the live axle, and not behind RA2 (live axle 2, if it's an 8x4)? The latter option will solve the issue of having limited WB and loading span options.
2. For the 3718il and 3723, why has AL placed the lift-axle ahead of the live axle, while TM has placed it behind RA2? I saw this portrayed as an advantage with the TM version, as pusher-type lift axles cause additional tyre wear.

Originally Posted by Rahul Rao

Has any one tried to have lift axles with double tyres. I have seen flat bed trailers with a crude lift mechanism, where the wheels are jacked up, and a pin placed below the leaf spring which is held by bush at one side and free sliding at other.

I've seen such crude lift mechanisms, but nothing pneumatic.

Originally Posted by Rahul Rao

Also are three axle bus chassis planned by AL or Tata. As per MV rules two axle buses are restricted to 12 M, but three axle ones are allowed 15M.

TM had displayed their Paradiso G7 coach based on a new 2128RE 3-axle chassis in an earlier auto expo, and there are pictures of it being tested on roads, in the internet.

Haven't heard of any multi-axle bus chassis from AL. But AMW had displayed a front engine 3-axle bus chassis in that same auto expo. It's not been heard of ever since.

IIRC, the maximum length for a 3-axle bus is 14.5M

[Ashley2]

Originally Posted by silversteed

Two questions:
1. Why isn't the lift-axle fitted ahead of the live axle, and not behind RA2 (live axle 2, if it's an 8x4)? The latter option will solve the issue of having limited WB and loading span options.

Even by providing a tag lift axle also, it doesn't solve the purpose. The problem is due to this setup it increases the load on front axle. This will lead to uneven load distribution and will cause higher front tyre wear and brake drum heating. By providing two front axles, the load is distributed in a better way and hence it gives better road grip especially when uneven loads are carried. That's the reason 31T tipper are always with twin front axles.

[quote=silversteed;35633852. For the 3718il and 3723, why has AL placed the lift-axle ahead of the live axle, while TM has placed it behind RA2? I saw this portrayed as an advantage with the TM version, as pusher-type lift axles cause additional tyre wear.[/QUOTE]

To be honest, it was the first time I have seen such mechanism. Even the upcoming BB 3723 is with same configuration as AL.
TM had issues of tyre wear in their 3118 pusher lift axle. That May be the reason for choosing tag lift axle. But even in that, in all our studies dead RA2 or last axle, has more wear due to the fact that they don't rotate, but rather skid when making a close turn. So an ordinary tag axle still doesn't solve the problem.
But still this all depends on chassis length and how other factors are overcoming this. As of now AL 3718il is in market for past 1 year and considerable numbers are running, compared to TM 3723. Tata 3718 has just hit the market and we shall see the performance henceforth.

If you are referring this to a FB page, even I came across that page. That was way misleading especially when they compared WB. WB measurement itself is defined differently for a tag lift axle and pusher lift axle. Also that page is too much praising and too much bashing on individual brands by giving one sided informations.Hopefully manufacturers are not behind this kind of cheap marketing.

Originally Posted by silversteed

IIRC, the maximum length for a 3-axle bus is 14.5M

Max length is 15m for a rigid multi axle.