The next item in the series is a large cog which was attached to the first Wanganui Town Bridge. Measuring 110 cm across the base and 180 cm high, it is part of the turning mechanism that allowed a section of the bridge to swing open and let ships through.
A swing span was a common feature of early bridges in New Zealand when shipping was still the best form of transportation of goods and people. Once the span opened, the ships would sail up to the sheltered basin near Shakespeare Bluff to discharge cargo.
Although not built until 1871, the structure had been in development since 1857 when a petition requesting a bridge was submitted to the Provincial Superintendent.
The first pile was driven into the riverbed in 1859, but the project met continuous halts due to failed contracts and arguments over the location.
The turbulence of the 1860s also halted work on the bridge, with fraught land purchases and the resulting wars causing tension and bringing threats to the area. Despite not having a permanent bridge, Whanganui was a prime transport location and became a major military site during this time.