"Martin Underwood" wrote in message
s.com...
"Clive" wrote in message
...
In message m, Martin
Underwood writes
Do crash gearboxes actually engage the teeth of the gearwheels or do
they engage dog-clutches (ie like a synchromesh box except without the
synchromesh cones)?

Cog meshing went out in the 1920s and since then it has always been
dogs.

So, given that post-1920s gearboxes had permanently-engaged cogs, of which
one at a time was locked onto the shaft by dog clutches, why did it take
so
long for manufacturers to add that other little refinement, synchromesh
cones?

Just had a look in Alan Townsin's "The Bristol Story, Part 1", which has a
picture of a KS-type 5-speed gearbox, with its top cover removed, on page
58.

That had constant mesh 3rd and 5th gears, direct drive 4th gear, and sliding
mesh cogs for 1st and 2nd. It was superseded in the 1950s by a synchromesh
version.
--
Terry Harper, Web Co-ordinator, The Omnibus Society
75th Anniversary 2004, see http://www.omnibussoc.org/75th.htm
E-mail:
URL: http://www.terry.harper.btinternet.co.uk/

In article ,
Adrian wrote:
John Rowland ) gurgled happily,
sounding much like they were saying :

The 253 used to always come in bunches of seven. I was told this by
someone, and I experienced it myself. Given that the old 253 was
effectively two overlapping routes, this isn't too surprising,
although 6 might be more expected.

Only because it's difficult for groups of three-and-a-half buses to arrive
simultaneously.

Sub-quantum bus theory could explain a lot.

Nick
--
"My objective at this stage was to work about 3 days per week"
-- Richard Parker in http://web.ukonline.co.uk/richard/cv78.html

On Sun, 20 Jun 2004 12:17:42 GMT, "Martin Underwood"
wrote:

I presume no vehicles (cars, lorries, buses) produced nowadays have
non-synchromesh gearboxes.

I doubt it, but many cars don't have a synchro on reverse (though most
do on first these days). Mine doesn't have one on reverse, and I
think that's the same of all Vauxhalls. I have heard of cars with
synchro on reverse recently, mind.

Neil

--
Neil Williams in Milton Keynes, UK
To e-mail use neil at the above domain

Martin Rich wrote:

: In any case it looks as though a lot of work has gone into design and
: manufacturing of these machines. If I didn't know better I'd see this
: as a sign that conductor operation was here to stay on a large
: scale...

While conductor operation is going to be phased out on London buses,
several new tram systems use conductors. Conductors are also going to
stay on trains - at least over longer distances - and on ferries.
All of them will need new ticket machines from time to time ...

.... Martin

On Sun, 20 Jun 2004 12:17:42 GMT, "Martin Underwood"
wrote:

"Bill Hayles" wrote in message
.. .

Things are different now, but when I took my (car) driving test in
1968, many cars didn't have synchromesh, so you got used to it from
the start.

As recent as 1968? I thought all cars had synchromesh on all gears except
sometimes first and reverse (where it's less important, as you're unlikely
to want to engage first or reverse while moving) long before that.

I took my test on a Ford Popular. I think that all the new cars had
synchromesh on most forward gears by then, but the vehicle I was
supplied with for my work (Land Rover) didn't.

I know that the Police driving manual "Roadcraft" makes reference to
double-declutching, and still recommends it even with a synchromesh box.
When I asked my IAM "observer" (instructor) his response was "that's a load
of archaic ******** [I'm paraphrasing!] - it's not necessary with a
synchromesh box and just slows your gearchanges down unnecessarily".

I am saying what I do; I'm not claiming it's current thinking or the
"correct way". But having driven that way for over 35 years, it is
sort of second nature!

Why do rally-drivers use clutchless gearchanges?

If you're asking me, I don't have a clue. My driving skills, such
as they are, are with the other end of the vehicle spectrum - big
and slow.


OK, when changing down, you're describing *increasing* the engine revs until
the gear slips in whereas I was describing blipping the engine revs over and
letting them *decrease* until the gear slips in.

Possible with a fast revving car. It would take far too long on the
buses I'm talking about. The Gardner engine was rumoured to get
from idle to full revs in just under a fortnight.



So very much the same technique as with a synchromesh gearbox. But... was it
as easy for the gear to engage when the engine revs matched if you didn't
have synchromesh?

Many of us thought it was.



I presume no vehicles (cars, lorries, buses) produced nowadays have
non-synchromesh gearboxes.

Interesting question. I don't know the answer.


--
Bill Hayles

http://billnot.com

On Sun, 20 Jun 2004 17:53:15 +0100, "Paul Dicken"
wrote:

I recall hearing stories about changing gear in RTs where there was a
particular hazard. Apparently, if you did not press the gear change pedal
firmly and only partially depressed it, the result was that it flew back
rapidly, propelling the driver's left leg into the air and creating a
painful groin strain!

That was the STL (before my time). The hazard was eliminated by
having a pneumatic rather than mechanical pedal.
--
Bill Hayles

http://billnot.com

Martin Rich ) gurgled happily, sounding much like
they were saying :

They were, but they were number series that never got issued before
the annual suffix was introduced - so they've been kept (with others)
for issue to newly imported pre-63 vehicles or to pre-63 vehicles that
have somehow lost their original numbers.

http://fleetdata.co.uk/agerelated.html

I seem to remember (but can't find my sources) that this type of new
number issued to an old vehicle is specifically non-transferable, so
it can't be sold on as a 'cherished number'

That's the theory, but it seems to vary according to the person issuing the
number - the SSL number I've got on the Solex is not stated on the V5 as
non-transferable. Mind you, they've also managed to put it down as
"declared new at first registration" and "manufactured 1962",
simultaneously...

DVLA. Gotta love 'em.

In message , Bill Hayles
writes
On Sun, 20 Jun 2004 12:17:42 GMT, "Martin Underwood"
wrote:

"Bill Hayles" wrote in message
. ..

Things are different now, but when I took my (car) driving test in
1968, many cars didn't have synchromesh, so you got used to it from
the start.

As recent as 1968? I thought all cars had synchromesh on all gears except
sometimes first and reverse (where it's less important, as you're unlikely
to want to engage first or reverse while moving) long before that.

I took my test on a Ford Popular. I think that all the new cars had
synchromesh on most forward gears by then, but the vehicle I was
supplied with for my work (Land Rover) didn't.

I know that the Police driving manual "Roadcraft" makes reference to
double-declutching, and still recommends it even with a synchromesh box.
Does it still recommend that? Interesting.

I double de-clutch when driving my Citroen 2CV, for two reasons.
Firstly, its (wonderful) gearbox is happier when I do and secondly I
learned to drive a crash gearbox bus before I ever sat in a car and sort
of became used to it! (Long story with which I won't bore you all
here!)

When I asked my IAM "observer" (instructor) his response was "that's a load
of archaic ******** [I'm paraphrasing!] - it's not necessary with a
synchromesh box and just slows your gearchanges down unnecessarily".
I was told exactly the same thing by an IAM Observer many years ago at a
Citroen Car Club Rally. But then he was so appalled at having to go
out with me *in* a 2CV that I think he was being negative about
everything.

I also now drive an Astra and in that I don't double de-clutch as it
doesn't "feel" happy with it. (Or else it requires more skill than I
have.)

I am saying what I do; I'm not claiming it's current thinking or the
"correct way". But having driven that way for over 35 years, it is
sort of second nature!
My thoughts are similar. (Apart from the 35 years bit!)

Love the H Van reference, by the way, Bill. Excellent taste you have.

Better go back to talking about buses, though.......
--
Ian Jelf, MITG, Birmingham, UK
Registered "Blue Badge" Tourist Guide for
London & the Heart of England
http://www.bluebadge.demon.co.uk

On 19/06/2004 10:36, in article ,
"Martin Rich" wrote:

I've occasionally wondered, in retrospect, and maybe somebody reading
this knows: did reverse work the same way on preselective gearboxes?
The thought of travelling forward, forgetting that you'd preselected
reverse, and accidentally touching the operating pedal, is fairly
frightening.

Thinking back to the days when I owned cars with preselectors - highly
unlikely; reverse was invariably at the opposite end of the quadrant to the
forward gears, beyond neutral, so preselection of reverse would be a major
movement of the lever, not something you'd be likely to do unwittingly. The
gate selector as on RMs might make it a bit less unlikely, but not much.

Presumably part of the idea was to ensure that, before power steering,
and also in days when hand signals were important, the driver could
arrange to have both hands free at tricky moments.

More a question of making gearchanging easier, I think. A lot of people
never really got the hang of crash boxes, and would crawl up hills in top
rather than try to change down.

On 20/06/2004 17:53, in article
, "Paul Dicken"
wrote:

I recall hearing stories about changing gear in RTs where there was a
particular hazard. Apparently, if you did not press the gear change pedal
firmly and only partially depressed it, the result was that it flew back
rapidly, propelling the driver's left leg into the air and creating a
painful groin strain!

Yes, cars with preselectors would sometimes play this trick on you as well.
Caused by the selector finger not engaging with the busbar IIRC.