On 28/1/21 12:20 pm, Michael Giddey wrote:
> A Loftus we use 25mm square hollow tubes to form the flange groove

> when we concrete track laid with T rails. This would not be necessary

> with grooved rails. The former Sydney system laid old ropes in the

> grooves to facilitate removal of excess concrete.

>

I think the thing here is actually timber form-work. They appear to be
going for some sort of inset paving around the tracks with two concrete
'strips' either side of the rails. Concept drawings show a variety of
street paving types.

 High density foam is 'wrapped' around the rails to provide both
vibration absorption and electrical isolation.