[yogibear007]

So should we have vehicles driving sideways rather than up front? Interesting thought on similar lines
I think there is an important factor in this design in the form of the overall breaking possibilities. If we have a design which is more in width than in length, or a square, the vehicle momentum transfers would probably not be so easy to maintain. Existing wide-bodied vehicles like the busses, trucks etc have their corresponding larger lengths also to aid in the handling/breaking characteristics. If we make them wider & less lengthier, I'm sure the entire vehicle design concept will have to be rethought.

Also, who’s stopping you from asking for four seats rather than three ones you get a model with three proper sits in the front? I have seen five people sitting in the front of the Boleros which ply between Igatpuri and Nasik stations on NH4 as taxis. One person actually sit astride the gear lever between the two sits while the driver merrily goes on shifting.

[k_nitin_r]

Originally Posted by norhog

This will eliminate the danger posed by having the third bench too close to the rear windshield thus having no crumple zone at the back in an event of a rear end shunt.

Also we keep hearing of our regulation regarding 4 mtr length but yet to hear any thing about the vehicles breadth

Rear crumple zones are usually not necessary because the vehicle would not be traveling backward at speeds over 20 km/hr. Crumple zones help in reducing the jolt when traveling at high speeds and for a low speed crash, seat belts alone would be sufficient for restraining passengers. At higher speeds, the shock to internal organs would cause death therefore there is a need to provide crumple zones, air bags, and seat belts that work together.

People generally have a perception that sedans are harder to drive than hatchbacks. They will surely have similar concerns when driving a wide-bodied vehicle, especially if it is marketed as such. The Hummer would be particularly difficult to navigate through the smaller lanes of Indian streets. Remember those roads that have 2-way traffic over a single lane? When you enter smaller villages, there's one lane and plants or trees on both sides so you have to squeeze in 2 cars while slightly brushing against the branches of trees and plants. Making the vehicles any wider would cause a problem on those roads, so using bench seats instead of bucket seats would be a simpler solution to the problem, though it would be a compromise in terms of comfort (not that the car seats in most cars are comfortable - the contours of the seats and position of the head rests are made for short folk, at least in the Japanese vehicles).

[honeybee]

Originally Posted by yogibear007

Also, who’s stopping you from asking for four seats rather than three ones you get a model with three proper sits in the front? I have seen five people sitting in the front of the Boleros which ply between Igatpuri and Nasik stations on NH4 as taxis. One person actually sit astride the gear lever between the two sits while the driver merrily goes on shifting.

Well, I don't want to ever end up in that position, I don't know what I would be shifting.

Originally Posted by k_nitin_r

Rear crumple zones are usually not necessary because the vehicle would not be traveling backward at speeds over 20 km/hr. Crumple zones help in reducing the jolt when traveling at high speeds and for a low speed crash, seat belts alone would be sufficient for restraining passengers. At higher speeds, the shock to internal organs would cause death therefore there is a need to provide crumple zones, air bags, and seat belts that work together.

If a stationary vehicle was hit from behind, wouldn't a rear crumple zone be necessary to prevent injuries? In this case people would be thrown backwards due to the inertia of their bodies and the vehicle being pushed ahead. You would need not only rear crumple zones but also good headrests to prevent neck injuries in this case.

[norhog]

Originally Posted by yogibear007

So should we have vehicles driving sideways rather than up front? Interesting thought on similar lines
I think there is an important factor in this design in the form of the overall breaking possibilities. If we have a design which is more in width than in length, or a square, the vehicle momentum transfers would probably not be so easy to maintain. Existing wide-bodied vehicles like the busses, trucks etc have their corresponding larger lengths also to aid in the handling/breaking characteristics. If we make them wider & less lengthier, I'm sure the entire vehicle design concept will have to be rethought.

Also, who’s stopping you from asking for four seats rather than three ones you get a model with three proper sits in the front? I have seen five people sitting in the front of the Boleros which ply between Igatpuri and Nasik stations on NH4 as taxis. One person actually sit astride the gear lever between the two sits while the driver merrily goes on shifting.

There is the Maruti Suzuki swift. When first launched is was the most squarish car in the market, and probably still is when you compare the wheel track and wheel base, but never had braking or other issues.

[norhog]

Here is an image of fiat multipa.
Please don't think of me as a agent of Fiat or am promoting their products.
My only point is we have sumos and other vehicles which are broad enough, what is stopping the manufacturers from incorporating this seating arrangement.
Mr K_Nitin_R has a valid point about squeezing through our narrow village roads but if trucks and suvs like sumo and scorpios can squeeze through then I guess a similarly sized 6 seater should also pass.

[yogibear007]

Originally Posted by norhog

There is the Maruti Suzuki swift. When first launched is was the most squarish car in the market, and probably still is when you compare the wheel track and wheel base, but never had braking or other issues.

Appreciate the example. The momentum dynamics would depend on the total frame. The overhangs at the extremities are very very important from these perspectives. In fact they decide the vehicle dynamics in most of the cases. Swift is not square if you think on overall basis. Come to think of it, neither can I think of any such car anywhere in the world which is like a square on an overall basis. May be the utility factor of the square volume might be reason, but still, the fact does support the physical mandate.
Rectangular side will always have more traction and flatter momentum transfer than the square one if small side is equal for both the shapes.

[norhog]

Originally Posted by honeybee

Well, I don't want to ever end up in that position, I don't know what I would be shifting.


If a stationary vehicle was hit from behind, wouldn't a rear crumple zone be necessary to prevent injuries? In this case people would be thrown backwards due to the inertia of their bodies and the vehicle being pushed ahead. You would need not only rear crumple zones but also good headrests to prevent neck injuries in this case.

Your first point is funny..

My views exactly about your second point. What if a truck or bus with its brake fail hits even at say 40 kmph. The last row persons head will directly strike the ingressing metal. You can surely picture this in your mind what with the last row head restrains just inches from the rear windshield. Check out a Ertiga parked any where near you and you will know what I mean.

Originally Posted by yogibear007

Appreciate the example. The momentum dynamics would depend on the total frame. The overhangs at the extremities are very very important from these perspectives. In fact they decide the vehicle dynamics in most of the cases. Swift is not square if you think on overall basis. Come to think of it, neither can I think of any such car anywhere in the world which is like a square on an overall basis. May be the utility factor of the square volume might be reason, but still, the fact does support the physical mandate.
Rectangular side will always have more traction and flatter momentum transfer than the square one if small side is equal for both the shapes.

Momentum dynamics..Sorry sir please explain a bit more if it is not a hassel with you I cannot understand..

[honeybee]

Originally Posted by norhog

You can surely picture this in your mind what with the last row head restrains just inches from the rear windshield. Check out a Ertiga parked any where near you and you will know what I mean.

The rear windscreen is usually high enough so in case of a rear shunt, it would be the metal below it which would take the impact. I remember when my M800 was hit from behind the rear windscreen remained intact, though the dicky door was smashed in and had to be replaced.

Also the rear seats are usually placed higher, so even if a truck rammed into the vehicle, the metal part of the dicky door and the pillars should be able to absorb a lot of the impact.

However I am not an automobile safety expert. These are plainly my personal opinions.

[S5157]

Toyota Qualis had a 9-seater/10 seater versions where 3 people could sit in front. Three seats in front take away the pleasure of driving where drivers shoulder would be always rubbing against the passenger. However three upfront makes good sense for taxi market where more people in a car can be an advantage. Hence we see such configuration in UV's whose versions are targeted at taxi markets. eg:- Qualis FS.

It seems Datsun has similar thoughts and has made an unofficial six passenger car?

[Arch-Angel]

The main reasons i felt for car manufacturers not allowing a 3 passenger setup in front would be for safety reasons primarily, because

1. The air bag module for the third person might interfere with the airbag of the passenger side.
2. The gear shift in most cars are positioned where the driver can use his left hand(in our case) freely.
3. A third passenger might block out the irvm of the car, which might result in poor awareness of the rear.

On a funny note, we had a trip long back, where three of us including the driver were sitting in the front and my cousin had his legs on either sides of the gear lever. My cousin who was sitting in the rear exclaimed to the driver and asked him to be careful not to shift the wrong gear .

[yogibear007]

Originally Posted by norhog

Momentum dynamics..Sorry sir please explain a bit more if it is not a hassel with you I cannot understand..

Sorry. Should have known. Pardon my ignorance bliss. The term mentioned here means the effects of physical forces on various sections of vehicle and the behavior of the entire frame when you try and change the speed of the vehicle or come to a stand still from a state of motion. Since the vehicle we are discussing here is assumed to be a car, the state of motion also is assumed to be relatively high.
The above 'momentum dynamics' is instantly evident when you rear end a car in front of you at any speeds although it is relatively less evident when you are slowing down from moderate speeds at moderate speeds. The same is also instantly evident when you break hard on a straight road in a vehicle like Maruti Omni and turn turtle.
I'm sure it would be very interesting to see a vehicle with a square shape or a 'sideway drive' breaking at these speeds.
Gosh. How did I miss. The all pervasive CG. We can still do it by sticking the bottom of a tank to the car and keeping it a convertible. But then would we like the drive ?? Count me out please.
So even if made a room for three in the front, still we are left with same length to be covered. So why not utilize the length rather than the ungainly width for the great seats to cushion the lovely bottoms ?
There are better designs being used by the way for this 'multiple seat' approach. Look at the school van converts of Metadors and the Autoricks redesigned for the same purpose. All have additional make shift rows behind the driver irrespective of the length. Serves the purpose.
Anyway, That would be Bal Ki Khal, right ?
Please continue

[saket77]

The transmission hump, dashboard designs for stereo/ Navigation system mounting, HVAC unit, etc. all rob the middle space which we are contemplating for the third passenger on the front row. Also, accidentally the middle passenger may put his foot in the foot well meant for the driver which can be disastrous; esp if kept under the clutch or the brake pedal.

Also, most Indian cars are not wide-bodied enough for the third front seat. Even the rear 3rd passenger is not really a welcome candidate in most cars. Other than that, adding the 3rd seat in the front may mean going for bench seats rather than buckets, which would strip down some luxury and at times utility of sliding & reclining seats.

Just my 2 cents on it!

Regards,
Saket

[avira_tk]

Originally Posted by Arch-Angel

The main reasons i felt for car manufacturers not allowing a 3 passenger setup in front would be for safety reasons primarily, because

1. The air bag module for the third person might interfere with the airbag of the passenger side.
2. The gear shift in most cars are positioned where the driver can use his left hand(in our case) freely.
3. A third passenger might block out the irvm of the car, which might result in poor awareness of the rear.

On a funny note, we had a trip long back, where three of us including the driver were sitting in the front and my cousin had his legs on either sides of the gear lever. My cousin who was sitting in the rear exclaimed to the driver and asked him to be careful not to shift the wrong gear .

The safety reason is quite suspect, Cadillac had the Airbank system for two passengers in front for their Seville or Deville sedans. I thnk they abandoned later because the seat design compromised lateral support for the driver. The Caddy had a column mounted shifter of course.

Visibility was not the issue as an 18 by 6 ft car was a barge and tight spaces were out of the question.

[norhog]

Sorry yogibear I am still at a loss here.
From what I know of mechanics and its application to cars the masses beyond the wheel axes has great effects on vehicle on road behavior.
Let me explain.
A car like older Porsche 911 had its engine beyond the rear wheel axes. On curves it has a tendency to over steer. Please see the diagram case A.
Most high performance sports cars have its engine inside the wheel axels to get better handling characteristics.
Now this is in horizontal plane.
On the vertical plane also the closer the CG is to the plane of the wheel axis the more stable the vehicle is, i.e less roll and pitch during changing directions and braking.
For example compare a maruti van or a SUV with high CG to a sweet handling car like zen and you get the picture.
Thus we see that the center of gravity being as close to the centre of the vehicle aids handling and will avoid a abnormal transfer of momentum as you specified.


Now having a over hang i.e the part beyond the wheel axis in front and back comprising of body work and plastic bumpers (Patra and fiber in local lingo) does not significantly contribute to the change in position of CG.
Best example swift desire old. Even though it had a fat rounded behind it did not add significantly to the weight and hence change in location of CG as it was mostly sheet metal and plastic bumper and heavy mechanical bits were at its original place.
So coming back to our discussion of having a slightly wider car if the CG is kept near the centre handling problems should not occur.
What I think (This is my gut feeling and I don’t have any calculations to prove it) is that a in a narrow car, the car makers can add a longutinal ribs to the floor pan and roof and make it rigid, but in a wider car significant amount of transverse stiffning would be required to attain rigidity of the body shell.
This will make manufacturing a bit more complex what with transverse members needing to be welded along the floor and roof.

Please see attachment here.

[Omtoatom]

Interesting topic! One of those one that stare right in your face and are still obscure enough to not be noticed!

Been wondering about the lack of this feature for some time - especially in modern-day UVs. I remember how it came in super handy in our yesteryear Fiat in the days when cars weren't very common in Indian households.

I'm often left wondering if safety alone is the reason for this seemingly obvious and glaring omission or are we missing something fundamental here??