In article , ian henden
says...

Shame it's wrong. Having actually driven a 15ft 9in high trailer quite
a lot, it is no worse than a normal height one.

Maybe, but a DD bus in high sidewinds, at motorway speed, is hairy.

Only to those with no experience of driving them.

An artic rig will have

a) more axles (so rather more weight low down) and

b) they will be distributed over a greater length of the vehicle (which
must contribute to directional stability) and

c) the load distribution of a truck is different. In a bus, half loaded,
then that half load will usually go and sit upstairs.... leaving the bottom
deck empty save for a few grannies....

And a bus has ballast weights.....


--
Conor

Light travels faster than sound. This is why some people appear bright
until you hear them speak.........

"Conor" wrote in message
.. .
In article , ian henden
says...

Shame it's wrong. Having actually driven a 15ft 9in high trailer quite
a lot, it is no worse than a normal height one.

Maybe, but a DD bus in high sidewinds, at motorway speed, is hairy.

Only to those with no experience of driving them.

'Spose 30+ years isn't enough? Initially Peterborough - Huntingdon -
Cambridge? Fen land, where wind whips striaght in from the Urals across the
North Sea and nothing much to abate it across East Anglia?

An artic rig will have

a) more axles (so rather more weight low down) and

b) they will be distributed over a greater length of the vehicle (which
must contribute to directional stability) and

c) the load distribution of a truck is different. In a bus, half loaded,
then that half load will usually go and sit upstairs.... leaving the
bottom
deck empty save for a few grannies....

And a bus has ballast weights.....

None that I am aware of, and I've seen a fair few buses and coaches being
broken up, never seen anything that might be called a "ballast weight".

Buses are subject to a "tilt" test, the angle of dangle being not so severe
for a DD as it is for a SD, but I can't remember off-hand what the angles
actually are. But we are not talking about being blown *over* .... the
problem is being blown *off-course*. With the smaller wheelbase of a bus,
that is a bigger problem than with a lorry's longer wheelbase. The problem
is also magnified with increased speed.

The reasons for a buses smaller wheelbase, compared with its length, are to
do with: having a wide door at the absolute front of the vehicle so the
driver can collect fares; that decides the location of the front axle; also,
a smaller wheelbase gives more manoeverability; rear overhang is a
"balancing" act with the front, and somewhere to put the engine. If the
engine were under the centre floor (an ideal location for stability, if not
servicing access), then the lower deck aisle would be too high (look at
1960s single deck Bristol MW, for example.) Can't get wheelchairs and
buggies up steps.

Biggest masses must be chassis and engine/gearbox, and the latter is usually
right at the back, 5 ft or so aft of the rear wheels - not the ideal
location for directional stability, but easy to get at when Things Go Wrong.
There are other, good, reasons for having the engine there.... out of the
way of passenger area, for a start. If the PTB could get away with having
engines at the front still, next to the driver, then we would still all be
using manual gearboxes. It's only the remote location of the engine that
prompted first, semi-automatics, and latterly, fullly automatic gearboxes.
Saves having complicated linkages under the floor (where ther isn't much
clearance anyway). (DAF BOVA has rear engine, and manual gearbox.... many
points of potential linkage wear twixt gearlever and gearbox... :0( ... try
driving a worn one, where you haven't a clue WHAT gear you might be in until
you try it!! )

Coming off M27 onto M275, where the road is high above other roads and the
foothills of Mount Solent, the wind has been whipping in over the harbour
recently. OK at reduced speeds, but, above 40 mph, it most certainly does
start to get hairy. The timetable demands 55mph plus for this ..... the
bus runs late instead, due to excessive wind conditions

Also a head wind can easily knock 10 mph off the top speed of 60 and a
tad mph (same as going up shallow hills on the motorway). (For some
reason, going the other way, you can't seem to acquire an *extra* 10 mph)...
You must have noticed some buses can overtake your lorry on the flat, but
then you can overtake them on an uphill?

One of Stagecoaches DDs got blown off the A10 near Streatham a few weeks ago
in similar circumstances. Made the national papers, AND the Sun. Buses don't
get blown *over* - just blown to one side or the other.... an involuntary
lane change, which one can cope with if there IS an empty lane to the
side... but not so much fun when there is only a drainage ditch!

Whilst I am quite happy to accept that you know a fair bit about driving an
artic, I am not so sure that you have had a lot of experience driving buses.
There are some differences, not all of which might be obvious.


---
IanH

In message , ian henden
writes
If the
engine were under the centre floor (an ideal location for stability, if not
servicing access), then the lower deck aisle would be too high (look at
1960s single deck Bristol MW, for example.) Can't get wheelchairs and
buggies up steps.
I've never heard of an MV, but in the mix of buses we had, our mainstay
was the Bristol/Lodeka double-deckers (crash boxes) and the Bristol RE
single-deckers (pre selector boxes). Weren't the latter mid-engined?
The VRs and the Leyland Nationals were rear-engined but the latter were
the only ones on the fleet with power steering.
--
Clive.

"Clive." wrote in message
...
In message , ian henden
writes
If the
engine were under the centre floor (an ideal location for stability, if
not
servicing access), then the lower deck aisle would be too high (look at
1960s single deck Bristol MW, for example.) Can't get wheelchairs and
buggies up steps.
I've never heard of an MV,

It's an MW.... see http://classicbristolbuses.thornet.co.uk/mw.htm


but in the mix of buses we had, our mainstay
was the Bristol/Lodeka double-deckers (crash boxes) and the Bristol RE
single-deckers (pre selector boxes)

Semi automatic
.. Weren't the latter mid-engined?

No... rear engined (see http://classicbristolbuses.thornet.co.uk/re.htm )
not really low floor, though

The VRs and the Leyland Nationals were rear-engined but the latter were
the only ones on the fleet with power steering.
--
Clive.

In message , ian henden
writes

"Clive." wrote in message
...
In message , ian henden
writes
If the
engine were under the centre floor (an ideal location for stability, if
not
servicing access), then the lower deck aisle would be too high (look at
1960s single deck Bristol MW, for example.) Can't get wheelchairs and
buggies up steps.
I've never heard of an MV,
It's an MW.... see http://classicbristolbuses.thornet.co.uk/mw.htm
I recognise it, we used to call then conker-boxes because the cab was
boxed in. They had a funny gearbox. The normal H but fifth was only
accessible from forth being right (towards the driver) then forward,
but in the mix of buses we had, our mainstay
was the Bristol/Lodeka double-deckers (crash boxes) and the Bristol RE
single-deckers (pre selector boxes)
Semi automatic
I don't know what you call semi automatic, but the gears were what I've
always called pre-selector, I drove enough of them.
. Weren't the latter mid-engined?
No... rear engined (see http://classicbristolbuses.thornet.co.uk/re.htm )
not really low floor, though
I didn't know that, but I suppose most drivers wouldn't.

--
Clive.

On Tue, 20 Mar 2007 19:39:56 +0000, "Clive."
wrote:

In message , ian henden
writes

It's an MW.... see http://classicbristolbuses.thornet.co.uk/mw.htm

I recognise it, we used to call then conker-boxes because the cab was
boxed in. They had a funny gearbox. The normal H but fifth was only
accessible from forth being right (towards the driver) then forward,

That was the standard layout for a Bristol, from the J-type onwards.
Dennis Lancets had a similar arrangement, except that 5th was a
pre-selector. Push the lever forward and hit the clutch pedal when you
were ready to change up.
--
Terry Harper
Website Coordinator, The Omnibus Society
http://www.omnibussoc.org

"Clive." wrote in message
...
In message , ian henden
writes

"Clive." wrote in message
...
In message , ian henden
writes
If the
engine were under the centre floor (an ideal location for stability, if
not
servicing access), then the lower deck aisle would be too high (look at
1960s single deck Bristol MW, for example.) Can't get wheelchairs and
buggies up steps.
I've never heard of an MV,
It's an MW.... see http://classicbristolbuses.thornet.co.uk/mw.htm
I recognise it, we used to call then conker-boxes because the cab was
boxed in. They had a funny gearbox. The normal H but fifth was only
accessible from forth being right (towards the driver) then forward,

"Dog-leg" fifth.

On ECOC, all the MW had them, but only the newer LFS had them - the
remainder had normal 4-speed boxes.

but in the mix of buses we had, our mainstay
was the Bristol/Lodeka double-deckers (crash boxes) and the Bristol RE
single-deckers (pre selector boxes)
Semi automatic
I don't know what you call semi automatic,

Semi - automatic: Tiny gear lever, no clutch. Change gear by actually moving
the gear lever. As per VR, RE, some LH, some FLF, some Leyland Leoprds
("pudding stick") and Tigers, and many others.

Pre-select : (usually tiny) gear lever. Put the lever in the gear you intend
to use next, but the vehicle continues to drive in it's previously selected
gear until you operate a "clutch" - it's actually called a gear-change
pedal! - on the floor. As per RM original equipment, I beleive, BICBW.

Never driven a pre-select bus (although plenty existed) apart from the
computer-controlled 10-speed version (scania?) a few years ago, but Ferret
scout cars and also Gainsborough medium wheeled tractors in the Army had
pre-selects, and I drove them there.

--
IanH

In message , ian henden
writes
Semi - automatic: Tiny gear lever, no clutch. Change gear by actually moving
the gear lever. As per VR, RE, some LH, some FLF, some Leyland Leoprds
("pudding stick") and Tigers, and many others.

Pre-select : (usually tiny) gear lever. Put the lever in the gear you intend
to use next, but the vehicle continues to drive in it's previously selected
gear until you operate a "clutch" - it's actually called a gear-change
pedal! - on the floor. As per RM original equipment, I beleive, BICBW.
Now I'm confused, the RE had a 1 inch long lever in a tiny gate on a
substantial mounting that stuck out of the steering wheel column on the
left, you changed gear but nothing happened until you lifted off of the
gas pedal, then the gear box would up change or other as required. So
the gear was pre selected but you got the change by "flashing" the pedal
up and down. What would you call it?
--
Clive.

In article , ian henden
says...
......

None that I am aware of, and I've seen a fair few buses and coaches being
broken up, never seen anything that might be called a "ballast weight".

My mistake. I thought I'd read somewhere that they did.


Whilst I am quite happy to accept that you know a fair bit about driving an
artic, I am not so sure that you have had a lot of experience driving buses.
There are some differences, not all of which might be obvious.

Indeed. Thanks for the explanations.


--
Conor

Light travels faster than sound. This is why some people appear bright
until you hear them speak.........

On Mar 20, 4:16 pm, "ian henden" wrote:
using manual gearboxes. It's only the remote location of the engine that
prompted first, semi-automatics, and latterly, fullly automatic gearboxes.
Saves having complicated linkages under the floor (where ther isn't much

I always thought having an autobox was simply to make the drivers
lives a bit easier in stop start traffic. I've never driven a bus but
I'd imagine having to change gear constantly on a 6 hour (or however
long it is) shift would become a right pain in the backside. Certainly
this is why cabbies almost always have autos.

You must have noticed some buses can overtake your lorry on the flat, but
then you can overtake them on an uphill?

Isn't that just because most bus engines are rather underpowered for
the weight of the vehicle? Presumably for fuel economy reasons and I
guess the presumption that in most situations they won't need to go
very fast anyway.

B2003