Hybrid buses

I saw on TV not long ago something about Hybrid buses being used in
London - not those hopeless fuel cell things but a diesel engine plus
electric motor. Are these out and about yet?

B2003

On 6 Jul, 11:05, Adrian <toomany2...@> wrote:
> Don't forget that the engine is basically just being used as a generator,
> therefore can run at optimum revs for the specific output - there's no
> requirement for any kind of useful rev range or torque curve.

True , and I suppose that will mitigate it somewhat. However
ultimately that engine will produce less power than a normal bus
engine so when relying on the engine alone its going to be slower
compared to the normal engine running at optimum gearing.

B2003

On 6 Jul, 11:16, Adrian <toomany2...@> wrote:
> <shrug>
> How often do bus engines require full power? Not very.

Agreed but when they do need it they really need it. The steep hills
around mill hill, highgate , hampstead and southgate spring to mind. A
hybrid bus with an exhausted battery going up one of those hills won't
be very popular with other motorists.

B2003

In article <ug5s83puqu0mq572v6nl26lr6hc7uov3nm@>, aooy65
@dsl.pipex.com says...

>
> Single decks are on the 360 (South Ken - Elephant) and the double deck
> is normally scheduled for the 141 (London Bridge - Palmers Green) but I
> believe it is away for further mods at present.
>
> An ethanol powered Scania double deck is scheduled for use on the 148
> but it's not been passed for operation yet.
>
>
From LOTS News Sunday 24 June

1) The Wrights Hybrid d/d HEV1 with Arriva was taken back to Wrights at
Ballymena on 18th June for mods to the system that keeps the traction
battery pack cool and which needs to be replaced by a more robust
system. It is unlikely to be back in London much before the end of
July.

Boltar wrote:
> On 6 Jul, 11:16, Adrian <toomany2...@> wrote:
>> <shrug>
>> How often do bus engines require full power? Not very.
>
> Agreed but when they do need it they really need it. The steep hills
> around mill hill, highgate , hampstead and southgate spring to mind.

Even if the buses were unsuitable for those areas, that's only about a dozen
routes. You wouldn't say that double deckers will never work in London
because of the Rotherhithe Tunnel.

On 6 Jul, 11:35, Adrian <toomany2...@> wrote:
> Boltar (boltar2....uk) gurgled happily, sounding much like they
> were saying :
>
> >> <shrug>
> >> How often do bus engines require full power? Not very.
> > Agreed but when they do need it they really need it. The steep hills
> > around mill hill, highgate , hampstead and southgate spring to mind. A
> > hybrid bus with an exhausted battery going up one of those hills won't
> > be very popular with other motorists.
>
> Nor would a diesel bus with an empty fuel tank...
>
> I really don't think it's going to be an issue.

A buses diesel fuel probably lasts all day. If these hybrid buses are
anything like hybrid cars then the battery would run down after only a
few miles without topping up which means its quite possible the bus
could be relying on engine power alone on difficult routes such as I
mentioned if the engine doesn't have the surplus to charge the battery
as well as supplying the motors.

B2003

In article <1183716910.744869.209760@57g2000hsv.. com>,
Boltar <boltar2003.uk> wrote:
> On 6 Jul, 11:05, Adrian <toomany2...@> wrote:
>> Don't forget that the engine is basically just being used as a generator,
>> therefore can run at optimum revs for the specific output - there's no
>> requirement for any kind of useful rev range or torque curve.
>
> True , and I suppose that will mitigate it somewhat. However
> ultimately that engine will produce less power than a normal bus
> engine so when relying on the engine alone its going to be slower
> compared to the normal engine running at optimum gearing.

Yes, but busses (especially in London) are very stop-start; if the engine
is busy recharging the battery when at a bus stop and/or red lights, it will
mitigate that to some extent.

Plus the regenerative braking, of course.

Exactly how far those effects help is something they will find out
as part of the trial, I guess.

--
Shenanigans! Shenanigans! Best of 3!
-- Flash

On 6 Jul, 11:26, Boltar <boltar2....uk> wrote:
> On 6 Jul, 11:16, Adrian <toomany2...@> wrote:
>
> > <shrug>
> > How often do bus engines require full power? Not very.
>
> Agreed but when they do need it they really need it. The steep hills
> around mill hill, highgate , hampstead and southgate spring to mind. A
> hybrid bus with an exhausted battery going up one of those hills won't
> be very popular with other motorists.
>
> B2003

They've been trialling these for 2 years now. This hasn't been an
issue. It might be if the bus was used on a route going up a mountain
without a stop. Not many of these in London.

On Jul 7, 12:30 pm, D7666 <d...@m> wrote:

> > They are branded in quite large letters front and rear:

> But London buses remain a mystery to me.


Supplementry question - are the hybrid buses out 7 days per week or
are they an SX operation ? Specifically knowing if they work on
sundays would be useful.

--
Nick