That Gold Coast curve is 25 metre radius, which is the accepted minimum
radius for fixed bogie trams nowadays, so there shouldn't be any
significant issue for the trams or tracks, provided the corner is traversed
at a very low speed.

I've no doubt that there are design issues on different models of trams
that have a bearing on the problem. The CAFs in Sydney traverse curves of
20 metre radius (plus vertical curvature) at the bottom of the Central
Station ramps, which is 5 metres below the design minimum curve radius for
those trams, so naturally, in the case of the CAFs, both tracks and trams
are progressively destroyed. The Citadis appear to be more strongly built,
so they destroy the tracks more than themselves, but their normal operation
is on CSELR which has a minimum radius of 25 metres and they hopefully
shouldn't have to suffer the vicissitudes of the IWLR track for much
longer. They do also ground their tails on that vertical curve at the
bottom of the Central ramp.

The worst thing with these fixed bogie trams is that have to go around
corners very slowly, which spins out the journey time if there are lots of
corners.

Tony P

On Friday 22 March 2024 at 15:11:11 UTC+11 Richard Youl wrote:

>

> Today I took photos of the curve between Nerang St and Scarborough St in

> Southport, outside the Cecil Hotel. This I believe is the sharpest curve on

> the system, at least one that is accessible. The shots were taken on the

> east-west pedestrian crossing.

>

> Photo 1 is the sharpest radius rail, the inside of the curve. It’s unclear

> whether the back of flanges is touching the check rail but if so, they are

> barely touching.

>

> Photo 2 is the corresponding running rail, second sharpest.

>

> Photo 3 is the outermost rail. I could not readily see the wear (cloudy

> day) so felt the wear with my little finger, and estimate that around 15mm

> at the most has been chewed away over the last 10+ years (includes test

> running before opening). No trace of lubricant was left on my finger.

>

> So it is apparent that not all ‘2 rooms and a bath’ trams chew the life

> out of curves. The big question is whether it is something about different

> tram designs or the flange shape.

>

> Richard

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