Oh dear. Not off to a good start then.

http://www.lbc.co.uk/new-routemaster...dy-photo-48777

B2003

In message , at 09:50:09 on Mon, 19 Dec
2011, d remarked:
Oh dear. Not off to a good start then.

http://www.lbc.co.uk/new-routemaster...dy-photo-48777

Sounds like the battery went flat.
--
Roland Perry

On Mon, 19 Dec 2011 10:28:03 +0000
Roland Perry wrote:
In message , at 09:50:09 on Mon, 19 Dec
2011, d remarked:
Oh dear. Not off to a good start then.

http://www.lbc.co.uk/new-routemaster...dy-photo-48777

Sounds like the battery went flat.

Who knows. Probably the hybrid drive system still has some issues to sort out.
On the radio they said it was going northbound so perhaps they already knew
about the problem and were trying to get it somewhere to sort it out but
didn't make it.

B2003

In message , at 10:52:03 on Mon, 19 Dec
2011, d remarked:
Oh dear. Not off to a good start then.

http://www.lbc.co.uk/new-routemaster...dy-photo-48777

Sounds like the battery went flat.

Who knows. Probably the hybrid drive system still has some issues to sort out.
On the radio they said it was going northbound so perhaps they already knew
about the problem and were trying to get it somewhere to sort it out but
didn't make it.

The circumstances (and some of the comments) are consistent with the
drive system becoming overloaded or overheated as a result of sustained
high speed.
--
Roland Perry

wrote in message

On Mon, 19 Dec 2011 10:28:03 +0000
Roland Perry wrote:
In message , at 09:50:09 on Mon, 19
Dec 2011, d remarked:
Oh dear. Not off to a good start then.

http://www.lbc.co.uk/new-routemaster...dy-photo-48777

Sounds like the battery went flat.

Who knows. Probably the hybrid drive system still has some issues to
sort out. On the radio they said it was going northbound so perhaps
they already knew about the problem and were trying to get it
somewhere to sort it out but didn't make it.

I speculate that the range-extender hybrid drive is designed for
stop-start operation, with the engine having lots of opportunities to
charge the battery when the bus is picking up pax or stoppd in traffic.
Regenerative brakes will also help keep the battery charged in
stop-start traffic. The engine may not have enough continuous output for
the bus to go long distances at relatively higher speeds on a motorway.
It's also possible that the battery wasn't fully charged at the start of
the journey. I wonder if, in normal operation, it's planned that the
batteries will be fully topped up overnight in the depot?

According to the Autocar review of the bus, the 4-cylinder diesel
generator has a max power of only 182bhp (which is less than my car),
which is used not only to charge the battery, but also to power the air
compressor for the brakes and steering. The battery is rated at 75kWh.

On Mon, 19 Dec 2011 11:26:32 +0000
Roland Perry wrote:
The circumstances (and some of the comments) are consistent with the
drive system becoming overloaded or overheated as a result of sustained
high speed.

I guess you mean the bit where it says "They claim the bus is not designed to
drive as far as Luton and therefore it needed a break". To me that sounds like
a bit of spin to disguise a problem. I can't believe the hybrid system can't
cope with doing 20 miles on a motorway without overheating. That would just be
**** poor engineering. Also it would've taken a week to drive it from the
factory in nothern ireland.

B2003

On Mon, 19 Dec 2011 11:37:34 -0000
"Recliner" wrote:
According to the Autocar review of the bus, the 4-cylinder diesel
generator has a max power of only 182bhp (which is less than my car),
which is used not only to charge the battery, but also to power the air
compressor for the brakes and steering. The battery is rated at 75kWh.

Its quite enough to move a double decker on the relatively shallow inclines
of a motorway even accounting for losses in converting to electical power.
Most buses arn't rated at much more than that anyway. If it can't cope with
steady running on a motorway with loads of nice cold air to keep it cool
god knows how it'll manage in 30C in summer slowly cooking in a london traffic
jam.

B2003

wrote in message

On Mon, 19 Dec 2011 11:37:34 -0000
"Recliner" wrote:
According to the Autocar review of the bus, the 4-cylinder diesel
generator has a max power of only 182bhp (which is less than my car),
which is used not only to charge the battery, but also to power the
air compressor for the brakes and steering. The battery is rated at
75kWh.

Its quite enough to move a double decker on the relatively shallow
inclines of a motorway even accounting for losses in converting to
electical power. Most buses arn't rated at much more than that
anyway. If it can't cope with steady running on a motorway with loads
of nice cold air to keep it cool
god knows how it'll manage in 30C in summer slowly cooking in a
london traffic jam.

You're assuming that it overheated, rather than my guess that the
battery was running low. I presume that they run the engine for optimum
economy, rather than for max power.

On Mon, 19 Dec 2011 11:55:54 -0000
"Recliner" wrote:
You're assuming that it overheated, rather than my guess that the
battery was running low. I presume that they run the engine for optimum
economy, rather than for max power.

I shouldn't make any difference. Once the battery is flat it runs off the
engine just like every hybrid car ever built.

B2003

wrote in message

On Mon, 19 Dec 2011 11:55:54 -0000
"Recliner" wrote:
You're assuming that it overheated, rather than my guess that the
battery was running low. I presume that they run the engine for
optimum economy, rather than for max power.

I shouldn't make any difference. Once the battery is flat it runs off
the engine just like every hybrid car ever built.

This is a range-extender hybrid, unlike most existing hybrid cars. In
other words, it's more like the Volt, not the Prius (ie, not all hybrid
cars are the same). So the only drive to the axle is from the 174bhp
motor, powered by the battery, with the generator just acting as a
part-time charger, which runs at optimum revs when it runs at all. If
the engine isn't charging the battery as fast as it's discharging, the
bus will have to stop or slow down for long enough for the charge to
accumulate again.

Autocar comments that the engine needed to run most of the time during
its short road test, probably because it wasn't getting much benefit
from regenerative braking, unlike on a normal bus route. This does
suggest that the engine isn't really up to powering the bus for a
sustained run at motorway speeds (unless the engine is pushed hard,
which would destroy the excellent economy and green claims). Wright
claims 11.2mpg for the Boris Bus, compared to 8.6mpg for Wright's Gemini
2 Hybrid (and 4.3mpg for a Citaro G bendy bus). The CO2 figures are also
much better (640g/km, compared to 864 and 1300, respectively).