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Post by ben on May 16, 2017 22:59:18 GMT
So, all busses (afaik) that work TfL routes are rear engined. However, in the past, front and mid engined busses also ran, and today highfloor mid-engined coaches still run into the London area.
What I'm wondering though is whether it would be possible to design a bus, of sufficient wheelbase, to be (partially) low floor but with a mid-engine layout? Any centre door would by necessity be pushed up close to the rear of the front wheel arch, to allow the front portion and disabled area to be low floor, resulting in a similar-ish look to the dual-door bodies worn by the Volvo-B10M chassis. However, behind that the floor would be higher to accommodate the engine underneath. The would allow precious extra seating space at the rear of the bus, something which with many modern classes takes up a large amount of space, and results in a very dark area to the back. This too would no longer be necessary as a decent sixed window could be fitted to the rear.
Has anyone made a chassis like this? What are the main sticking point that, if not, have proved to be insurmountable? Must admit I've not had much luck finding information on chassis manufacturers websites about any of their products.
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Post by snowman on May 17, 2017 5:35:53 GMT
So, all busses (afaik) that work TfL routes are rear engined. However, in the past, front and mid engined busses also ran, and today highfloor mid-engined coaches still run into the London area. What I'm wondering though is whether it would be possible to design a bus, of sufficient wheelbase, to be (partially) low floor but with a mid-engine layout? Any centre door would by necessity be pushed up close to the rear of the front wheel arch, to allow the front portion and disabled area to be low floor, resulting in a similar-ish look to the dual-door bodies worn by the Volvo-B10M chassis. However, behind that the floor would be higher to accommodate the engine underneath. The would allow precious extra seating space at the rear of the bus, something which with many modern classes takes up a large amount of space, and results in a very dark area to the back. This too would no longer be necessary as a decent sixed window could be fitted to the rear. Has anyone made a chassis like this? What are the main sticking point that, if not, have proved to be insurmountable? Must admit I've not had much luck finding information on chassis manufacturers websites about any of their products. No it's no longer possible to make a thin flat engine because to meet modern emissions you need the turbos and exhaust manifold mounted on side of block, to run hot, otherwise the exhaust gas is not clean enough. On single deck buses can add an extra step or two in floor and mount engine below floor, rather than behind seats, (this is what you are seeing on coaches), can't do this on double decks due to lack of headroom. The alternative is a vertical engine in a corner (normally used when there is a rear exit door opposite side, common on continent, but not in UK on single decks) Of course if you do away with the diesel (e.g. a trolleybus) don't need engine space |
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Post by YY13VKP on May 17, 2017 9:45:50 GMT
So, all busses (afaik) that work TfL routes are rear engined. However, in the past, front and mid engined busses also ran, and today highfloor mid-engined coaches still run into the London area. What I'm wondering though is whether it would be possible to design a bus, of sufficient wheelbase, to be (partially) low floor but with a mid-engine layout? Any centre door would by necessity be pushed up close to the rear of the front wheel arch, to allow the front portion and disabled area to be low floor, resulting in a similar-ish look to the dual-door bodies worn by the Volvo-B10M chassis. However, behind that the floor would be higher to accommodate the engine underneath. The would allow precious extra seating space at the rear of the bus, something which with many modern classes takes up a large amount of space, and results in a very dark area to the back. This too would no longer be necessary as a decent sixed window could be fitted to the rear. Has anyone made a chassis like this? What are the main sticking point that, if not, have proved to be insurmountable? Must admit I've not had much luck finding information on chassis manufacturers websites about any of their products. Of course if you do away with the diesel (e.g. a trolleybus) don't need engine space Or use electric power |
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Post by rmz19 on May 17, 2017 10:45:26 GMT
Of course if you do away with the diesel (e.g. a trolleybus) don't need engine space Or use electric power Although the electric BYD Double Decks on the 98 are great buses, they have a large reserved space to accommodate the electric powertrain, therefore they have a significantly reduced amount of space in the lower deck. Whereas the BYD SDs and the I2E don't have this issue, perhaps this is due to the use of the roof space to accommodate the electrical mechanics. The BYD DD could've been given a longer wheelbase to eradicate the issue of lower deck space. |
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Post by snoggle on May 17, 2017 11:02:39 GMT
Although the electric BYD Double Decks on the 98 are great buses, they have a large reserved space to accommodate the electric powertrain, therefore they have a significantly reduced amount of space in the lower deck. Whereas the BYD SDs and the I2E don't have this issue, perhaps this is due to the use of the roof space to accommodate the electrical mechanics. The BYD DD could've been given a longer wheelbase to eradicate the issue of lower deck space. Wouldn't making it longer simply increase its weight thus probably breaching the axle weight limit? I think these buses already benefit from the exemption that allows some vehicles to have slightly higher axle weight limits. The only way you'll get an effective all electric decker is when there is a further breakthrough in battery technology that means fewer batteries are needed for a given power output or batteries get smaller and lighter for a given output. I remain a tad sceptical about all these whizzy new technologies - note that Reading and EYMS have removed the hybrid drivetrain and reverted to full diesel on their early E40Hs because battery replacement costs were prohibitive. No wonder Reading has switched to gas - cleaner emissions and no battery costs. I wonder what sort of financial time bomb London and its operators are sitting on with the dash towards hybrids? If the Mayor wants a cleaner environment and an "electric" transport network then the answer is utterly obvious even though it would be expensive and disruptive in the short term. However the long term dividends would be enormous. And I'm not even going to name the modes because we've discussed them lots of times before.  |
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Post by redexpress on May 17, 2017 11:05:18 GMT
Although the electric BYD Double Decks on the 98 are great buses, they have a large reserved space to accommodate the electric powertrain, therefore they have a significantly reduced amount of space in the lower deck. Whereas the BYD SDs and the I2E don't have this issue, perhaps this is due to the use of the roof space to accommodate the electrical mechanics. The BYD DD could've been given a longer wheelbase to eradicate the issue of lower deck space. I don't know how much the BYD DDs weigh, but I'd guess that a longer wheelbase and extra passenger capacity might exceed axle weight limits? |
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