Yes the Pilchers were kings of yawing. A shame none survive. Mind you, when we had Birney 217 operating at speed along Dandenong Road about 1972 with Jim Dowel at the controls, she wagged a bit too. Dave Menzies ----- Original Message ----- From: C. B. To:TramsDownUnder@... Sent: Saturday, July 14, 2012 11:47 AM Subject: Re: [TramsDownUnder] Re: Report slams Citadis design flaws
The business of yawing....go back to the 1920s and 1930s, in Britain, where most trams were double deck 4-wheelers. Most of these cars "tail-wagged" or "jazzed" -- a fairly rapid side to side motion. Big difference here was that in those days tram drivers stood to drive the tram, and were able to absorb most of the heaving and jerking movements. Driving in a sitting position is a completely different game! The driver is thrown about just like the passengers -- perhaps worse as he is right at the end of the car. It is difficult and very tiring sitting being thrown about for hours on end. Passengers are fortunate that their stay on such a car is brief!
The classic example of jazzing trams could be found in the original Edinburgh tram system. The ex-Manchester "Pilcher" cars swung about and jazzed like you wouldn't believe! At speed, on decent straight track these cars would tail-wag so hard that the hand brake chains would slap the underside of the platforms. There was a one-legged seat(!) provided for the driver, but the car motion was so violent that drivers found it more comfortable and less tiring to stand. I doubt that the new Edinburgh trams will perform like this, but with a large end overhang, who knows what will happen as the track becomes worn? I suppose such "multiple jazzing" would correctly be called "snaking".....which brings me to British Rail's EMU Class 303 units, but that is another story!!
On 14 July 2012 12:23, Tony Prescott <prescottt@...> wrote:
--- InTramsDownUnder@..., "brian_weedon" <brian_weedon@...> wrote: > > http://www.theage.com.au/victoria/trams-cop-a-low-blow-as-report-slams-design-flaws-20120713-221ki.html
> > Tram drivers have also suffered repetitive strain injuries from driving Citadis trams, because they rock heavily from side to side. >
I wonder if they're referring here to a lateral rolling motion or (more likely I think) yawing? And is this about the earlier Citadis or the Mulhouse version too?
The Citadis *is* is a design flaw! The first of many dumbed-down modern trams designed for those who know nothing about trams - which unfortunately is most of those who commission new light rail systems. It's the Toyota Camry of trams and successful for the same reasons. You don't succeed in business without being astute. Even Skoda is jumping on the bandwagon - after producing the perfect tram for those who know about trams it's now doing one for those who know nothing, not to mention joining the current European price race to the bottom. (Except Australia of course where the seller names the price!)
The Czechs use mirrors as well as cameras - too risky to have all the eggs in one basket.
cheers Tony P