On 21/08/2017 1:52 PM, Tony Gallowayarg@... [TramsDownUnder] wrote:
> Flexible switches are used because it eliminates a couple of wear and potential failure points - they are universal in railway turnouts these days, and I used to have an Electric Traction magazine from 1960 that had a news item that said the M&MTB was investigating flexible switch turnouts as used in, I think, Amsterdam.

They made some as trials - and one (unused) is amongst the special work in a pile at Byalnds.
http://tdu.to/210777/0/point-blade_bylands_8june2014.jpg

>

> Compared to producing castings and forgings, machining a length of rail would be pretty cheap these days with CNC controlled mills.

>

Agreed.  It seems to me that the tricky bit is the metallurgy of a piece of steel that is hard enough to not wear quickly while being flexible enough to bend without cracks.

A few years back Dave Hinman & I visited Davies & Baird and saw a stack of point blades they were making for Yarra Trams as spares for the traditional points.
http://tdu.to/Point-blades_Davies-and-Baird_22Oct2014.JPG

I was a bit surprised to see that they had large pivots at the heel end - the traditional 'Hecla' blade had a simple flat bearing held in place with an adjustable end plate.

Mal Rowe - who might have seen the last traditional point blades made in Australia.