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Old 30th August 2008, 20:42   #121
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Quote:
Originally Posted by amitpunjani View Post
hi

I have been always wondering, how does the A/C works in these huge buses. Have they got separate diesel engine to run the compressor or the working of the A/C is exactly same as passengers cars???
Thanks
Amit
No Amit. They don't have a separate diesel engine for the airconditioning compressor.

The compressor is a powerful unit, that is run by the main engine and probably consumes substantial horsepower. However even minus the power consumed by the compressor, the engine has adequate reserve horsepower for acceleration to freeway speeds and overtaking.

As the volume of air in the bus is huge, there have to be multiple nozzles. Ideally one per seat. These are individually controllable and orientable.
In addition, there are cold air outlets along the center of the ceiling which continuously bleed cold air into the bus.

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Old 31st August 2008, 10:18   #122
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Hi Ram

Thanks for the explanation.


Amit
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Old 16th September 2008, 08:36   #123
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Neeta Volvo B7R driven at idle.

Yesterday, 15-Sep-2008, being a Monday morning, I could not get a seat aboard the 07:00 Shivneri Volvo to Pune from Chembur.

So I flagged down a Neeta Volvo -- a beat up old crate.

By the time we reached Wakad, a spring on the accelerator cable, snapped inside the engine compartment.

The driver stopped the bus and walked to the back of the bus to survey the situation, while the passengers twiddled their thumbs.

He tied the accelerator cable at 1500 rpm and chose to keep on going (from Wakad to Pune rly. stn.) at near idle rpm, coaxing the vehicle along in 1st and 2nd Gear with the clutch alone.

He told us, all saucer-eyed, that there was danger or wearing out the clutch plate on the Volvo B7R, which costs Rs. 85,000.

This is the condition of Neeta's aging fleet of Volvo coaches.

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Old 16th September 2008, 09:52   #124
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I believe both Volvo city bus and coach has the same D7E 7.1 ltr engine which provides 290hp. Not sure if city buses really require that kind of power.
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Old 16th September 2008, 13:58   #125
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Why does a city bus need so much power?

Quote:
Originally Posted by appuchan View Post
Not sure if city buses really require that kind of power.
Free-flowing traffic is the lifeline of the nation.

Our world of traffic today, is a world of zippy fuel-injected Marutis, Hyundai Santros and Tata Indicas
Should they be hindered by a lumbering bus?

The bus engine needs to:
  • drive the air-conditioner -- enough power to comfort fifty passengers plus standees in our sweltering tropical afternoons.
  • overcome the power consuming Euro-III pollution control equipment
  • have enough reserve power to accelerate the bus from 0 to 60 km/h in a meaningful timeframe.

In a city like Bombay, city buses do use the Eastern Express and Western Express highways for significant portions of their routes. Do you want them to forever lag behind the demands of modern city traffic? It's all about power-to-weight ratio. BHP per ton.

Think about it. Underpowered buses will become bullock-cart-like hindrances to the free flow of traffic.

The Volvo B9L has a 6-cylinder D9B 9-litre engine that puts out 310 bhp and 1400 Nm of torque. It is certified according to Euro 4 and also available in a Euro 5 variant.

Volvo B7R reviews?-2008volvob9l.jpg

It weighs 19 tons GVW.

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Old 16th September 2008, 17:45   #126
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Quote:
Originally Posted by appuchan View Post
I believe both Volvo city bus and coach has the same D7E 7.1 ltr engine which provides 290hp. Not sure if city buses really require that kind of power.
It has pros and cons. Good thing is that now they can keep up with traffic and climb ghats easily, but the bad thing is overspeeding which has already caused many an accident.

Pardon the cliché, but with great power comes great responsibility and its not a good idea with our reckless Indian drivers. Can you imagine if commercial pilots had the same discipline as our bus drivers??? My opinion is that electronic speed limiters and better brakes are paramount on these powerful buses.

THe logic applies more to intercity coaches, but speeding city buses are a nuisance too.

Last edited by Mpower : 16th September 2008 at 17:46.
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Old 16th September 2008, 19:35   #127
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the last pic is tragic! such an enormous beast gone down the drain, rendered useless!
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Old 16th September 2008, 19:57   #128
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Rest assured the airsuspension and the design of the coach keeps it on the road even at good speeds on a curve. As far as the brakes go they have an retarder on the B7 R coatch. Most modern cars have a lot technology from the volvo labs in sweden including airbags,impact beam, and crumple zones.
Braking in the newest volvo trucks and coaches employs one or more of the following.In spite of this there are accidents due to rash driving and the ability of non trained drivers to harness the featurs and the power of the coatch. Also the road conditions in india are so bad ..and i happened to see my first volvo upset on NH7 a few days ago.

Sorry guys the enter button got stuck....cont.
  • Electronic Brake System (EBS) operated by compressed air standard with air springs
  • Panic Brake Assistance cuts stopping distance
  • Automatic brake force adjustment between tractor and trailer
  • Brake disc with flexible attachment for long life
  • Electronic Stability Program available on 4x2, 6x2 and 6x4 tractors
  • Exhaust Pressure Governor available as exhaust brake
  • Compact retarder with VEB+ provides braking effect of about 865 kW
Newly developed VEB+
Volvo Engine Brake is now taking a giant step forward. The optional VEB+ that is being introduced on the D16 represents a considerable increase in braking power. It is the very latest and most effective technology in the field of auxiliary brakes.
VEB+ is based on interaction between the exhaust pressure governor and VCB (Volvo Compression Brake). Maximum braking power with VEB+ is as high as about 425 kW at 2200 rpm.
Exhaust Pressure Governor as exhaust brake
The EPG (Exhaust Pressure Governor) is located at the turbocharger's exhaust outlet. On the D16, the EPG is combined with an on-off shutter that controls brake capacity. During engine braking, the EPG restricts the exhaust gas flow and thus generates back-pressure against the pistons.
Maximum braking effect with EPG is about 230 kW at 2200 rpm.
Compact retarder brakes during gearchange
Volvo's RET-TH compact retarder is a gearbox-mounted hydraulic retarder that effectively supplements the vehicle's standard braking system. It suits most manual gearboxes as well as I-Shift. Since the retarder is attached to the propeller shaft, braking effect is also utilised during gearchanges.
Together with the latest generation of I-Shift, RET-TH provides extremely high braking capacity.
Maximum braking effect with the compact retarder combined with EPG is about 670 kW, and with VEB+ it is about 865 kW.



Find attached details on the PDF.
Attached Files
File Type: pdf G1803_Volvo_Bus_RB_E_END.pdf (79.8 KB, 4135 views)
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Old 22nd September 2008, 11:38   #129
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Volvo: cheap cost cutting takes its toll.

I booked a bus ticket via redbus.in for a Volvo from Chennai to Hyderabad.
The service chosen was Omer KGN.
A day prior to the journey I recieved a phone call that this bus is cancelled and I am rescheduled to a bus from BHARTI JAHAN travels.

The seat number was J3. It happens to be the last row in this bus.
The departure time was given as 8:00 PM from Koyembedu.

I arrive at the terminus at 7:30 PM and am then informed that the bus will leave at 8:30 PM.
So I end up wasting close to 30 mins at the terminus for a bus that finally arrives at 8:15 PM and leaves by 8:40 PM.

If you are travvelling by a Volvo. NEVER and I repeat NEVER accept the last row.
The seats recline less than 50% of what the other seats can.

This was a semi sleeper bus. All seats except the last row have support for the calves.
What this means is that you keep sliding of the seat every time the brakes are applied hard.

NO AC reaches the last row. There was no vent on top. As simple as that.
Imagine paying 800 bucks and getting a bus in which you are sweating it out.

And not only are you sweating but everyone in this tightly packed row is also sweating.
Horrible is not the right word but its the first that comes to my mind.

A verbal slanging match started between me and the bus operators.
It ended in the morning when I finally disembarked.
Actualy it did not. We continued our abuses for a brief period after that as well.

I am blessed with a loud voice.
There were no children in the bus.

So I even sang a song in which I wished the people who designed this bus a lifetime of haemorhides and a slow very painful death by sphyliss.
I now feel I went over the top.
Maybe I should apologise to the other passengers who got incovienenced with my loud ranting every 15 mins after a brief period of silence.

But they can kiss my ***.

Not one of the other passengers had the decency to join four people stuck in a bad bad situation caused by the greed of these bus operators.

So I also sang Saare Jahan se acha for them.

I am very very disappointed in the BHARTI JAHAN travvels.
To just earn some money they are willing to push a passenger into so much discomfort.
Total number of seats in this bus was 40.

I am also disappointed in Redbus.in
They should do a better quality check of the services on offer.

One more thing about Redbus.
I booked a seat in a 2+2 Hi Tech bus from Omer KGN.
The bus that took me to Chennai was a Shama Sardar.
The website mentioned arrival time at 8:00 AM.
THe bus driver told us no way before noon before we even commenced the journey.

I am never ever going to use Redbus again. However I have emailed these incidents to them.
Will post any replies I get.

Till then every time I remember them I wish them a nice and good case of diaoreha.


PS: I was able to somehow use some newspapers to pipe the cold air from an over head line.
So it became a litle bearable as the night progressed.

PS2: I remember them and have started praying. Please join me in my prayers. Lets wish them a good case of Delhi Belly.
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Old 23rd September 2008, 13:12   #130
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Quote:
Originally Posted by condor View Post
Ram & Bunny, I can only smile in appreciation, reading your posts about the rims, tyres, et al ..

For all the comfort and sophistication that the Volvo's brought to Indian road travel, I am not all for these Volvo's. I prefer the seating in the 2+1 seating arrangement busses, where there is much more space. The Volvo's I have seen are either 2+2, or sleeper coaches.

I would still take seat #1 in the Volvo .. Love the view.

One major grouse about a lot of these Volvo's - they Smoke. Much more than the good old Leylands & Tata's.
Few Volvo buses here in Madurai too emit visible black smoke.
Exhaust smoke could be because of not replacing filters in time or not servicing the fuel system.
It is more visible in Volvo because the exhaust is at the rear whereas Leyland and Tata have at the side.

Talking about seat arrangement, Buses here in TN have 2+3 arrangement for 8 hours journey. And in most routes you do not have the option of selecting 2+2 buses because they are not there.
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Old 23rd September 2008, 14:20   #131
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Quote:
Originally Posted by stampro View Post
Few Volvo buses here in Madurai too emit visible black smoke.
Exhaust smoke could be because of not replacing filters in time or not servicing the fuel system.
It is more visible in Volvo because the exhaust is at the rear whereas Leyland and Tata have at the side.

Talking about seat arrangement, Buses here in TN have 2+3 arrangement for 8 hours journey. And in most routes you do not have the option of selecting 2+2 buses because they are not there.
I think almost all the Volvos have 2+2 seating. 2+3 is found on the non-Push Back Airbuses. Some Volvos on the Chn-Blr route have 2+1 system too.
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Old 23rd September 2008, 15:00   #132
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i think the worst maintained volvo is owned by garuda
i saw it yesturday,the bus was literaly torn apart the smoke of the exhaust was comming from the entire rear portion of the bus, the body was in a shape worse than any of the cheapest ST buses in maharashra
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Old 23rd September 2008, 15:16   #133
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Garuda is the name of the Volvo Service run by APSRTC. And yes, they are badly maintained!
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Old 23rd September 2008, 16:32   #134
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I have just received a call from Redbus.
They have promised to take strong action on the Volvo bus operator and keep me posted on it.

The person on the other end sounded genuinely concerned and very angry at the bad service meted out. Lets see what happens.
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Old 23rd September 2008, 17:10   #135
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Yes, the Garuda Buses do look like they have been in use since 1947 without any repairs. (the insides though, are not all that bad IMO)

I still prefer them because they are the only ones going out of hyderabad, that maintain time.
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