Potters Hugh and Jacqueline Roscoe were among the queues of people collecting bags of free clay dug from the New Lynn Rail trench.
A wide range of people turned up to the site, some coming from as far as Taranaki.
By the end of the day rail network company Ontrack
and its contractor Fletcher Construction - aided by the Waitakere City Council, had given out 8cu m of clay.
Two people planned to use the clay to build pizza ovens.
Others in the queue included a clay-court tennis club, and schools and pottery enthusiasts keen to make the most of some free clay, which can sell for up to $60 a bag.
More than 90,000cu m of material is being excavated during the project, which lower New Lynn's railway lowered into an 8m-deep trench.
It is due to be completed, with the rest of the transport hub, in 2010.
Clay from the New Lynn area has a long history with potters.
It was once used for Crown Lynn tableware, the origins of which can be traced back to the 1850s.
