Hornby Dublo diamonds

[Colin_McLeod]

A question that I am curious about. Hornby Dublo sold 3 rail diamond crossings in left hand and right hand versions.

 

Why the two types? Any modern diamonds are symmetric.

 

Colin

[russ p]

I seem to remember the super 4 and early system 6 were handed.

Was there ever a five series of triang track?

[Golden Fleece 30]

A question that I am curious about. Hornby Dublo sold 3 rail diamond crossings in left hand and right hand versions.

 

Why the two types? Any modern diamonds are symmetric.

 

Colin

Tri-ang also sold left and right diamonds in Super 4 and series 6 track, Dublo also did in 2-rail. The answer being that it was to match the geometry of the points to give parallel ends on the main lines and to keep the centres the correct distance apart. In both Dublo and Tri-ang the "branch" exit had to be made up of shorter straights that would never equal a standard length. Looking at a point you will notice that the curve part extends further than the straight so a shorter crossover line is required but a longer main line to match the point end.

 

With the likes of Peco, and old Wrenn, Gem etc, using flexible track did not need to have the same constraints.

 

Garry

[Il Grifone]

As Garry said, it's a question of geometry (and therefore 'boring' by definition   ). There are also  rather an awful piece of engineering (untypically Meccano). The large piece of plastic in the centre is prone to warping, which renders the unit useless. I believe it's bakelite and allergic to attempts to straighten it (a defect shared by the uncoupling rails).

 

I was given a pair as a child. I often ended up using them as straight half rails....  You can use them to make a rather crude external single (or even double) slip.

[Golden Fleece 30]

As Garry said, it's a question of geometry (and therefore 'boring' by definition   ). There are also  rather an awful piece of engineering (untypically Meccano). The large piece of plastic in the centre is prone to warping, which renders the unit useless. I believe it's bakelite and allergic to attempts to straighten it (a defect shared by the uncoupling rails).

 

I was given a pair as a child. I often ended up using them as straight half rails....  You can use them to make a rather crude external single (or even double) slip.

As David has mentioned the centres are prone to warping, why I don't know as Bakelite plugs never seemed to (as far as I know).  When I did have Dublo 3-rail track fastened to a board I drilled and countersunk the centre to hold it down flat with a screw, but, you must make sure the hole on the metal on the underside is larger so the screw does not short out if the centre collector touches it as a train passes over. This actually did give a lot better running without the "Jump" that often happened when a train passed over.

 

Garry

[Il Grifone]

Hi Garry,

 

They must have been some sort of substitute plastic. Bakelite is thermosetting and once moulded stays put. Any attempt to bend it results in fracture. (Been there. done that....)

 

David

[Colin_McLeod]

Thanks for the replies. I understand it now.