In the early 1990s, I was friends with a German railways engineer in Karlsruhe who was working on the tram-train project.

I don't recall all the details but the figure of 3 mm difference in flange with, I think it was, was a bone of contention but obviously it was solved.

As the Channel Tunnel trains initially ran on BR tracks, obviously there is little difference between European and British rail standards so why they could not ask Karlsruhe for all the details and have been up and running years ago is clearly beyond our comprehension.

When you think of all the rubbish in the original Board of Trade tramway regulations, I suppose it is a miracle they have got as far as I have with Sheffield.

Regards,

> On 17 Sep 2017, at 5:32 am, Matthew Geiermatthew@... [TramsDownUnder] TramsDownUnder@...> wrote:

>

>

>

> On 16/09/17 12:09,mcloughlin.dj@... [TramsDownUnder] wrote:

> >

>

> > See this except:

> >

> >

> > > one underestimated challenge has been the development of a wheel profile suitable for use on both Supertram and Network Rail tracks. At present, he says, all seven vehicles have been delivered with the standard wheel profile used on the rest of the tram fleet. Four cars are to be modified with new wheels to operate the Sheffield – Rotherham service.

> >

>

> Something Sydney did back in 1996 with the Variotram and it's hybrid profile wheels.

>

> They are literally re-inventing an already re-invented wheel.

>

> The attached is part of a drawing with an original date of 1995 and it makes reference to an even older ABB drawing. And presumably Karlsruhe had to solve this issue 'way back'.

>

> The key item is the stepped wheel back.

>

> > Full story including photo of the new tram. Hmm they are Spanish trams!

>

> But not CAF, Vossloh Citylink. Vossloh rail has recently been acquired by Stadler.

>

> Tram-train pioneer Karlsruhe have been getting them too. Sheffield's ones are based on the Karlsruhe ones.

>

> >

> > http://www.metro-report.com/news/light-rail/single-view/view/sheffield-tram-train-enters-service.html

> >

>

> An only just going into service now, the first was delivered in November 2015! Nearly 2 years getting in the way in the depot before being pressed into passenger service.

>

> And TfNSW looks to the UK to for 'expertise'.

>

> <Hybrid tram wheel profile (Sydney).png>