14 December 2017
| Major Milestones

Installation of Super T girders at the Gore Highway


There is no getting around the 20-minute delays we will be causing as we lift girders over the Gore Highway for two nights next week. Truckies and party goers – we are sorry!

We are building the crane, that will lift these girders, on the side of the road. Luckily there is just enough room to do this or there could have been a lot worse delays!

Building and dismantling the crane is a massive undertaking. It is like a huge Ikea project with a few hundred bolts, over 25 components and a lot of cable. Unlike an Ikea project, we have an entire crew to put everything together, we don’t have to use an Allan key and we understand the instruction manual.

The crane we are using to install the Super T girders on the Gore Highway is a 280T crawler crane with superlift. Before we can even start to piece the crane together, approximately 30 semi-trailer loads are required to bring all the crane components to site.

To build the crane, we start by constructing the car body and attaching the tracks beneath it. While this is happening other crew members are fitting together the front and back (stinger/derrick) boom sections. Once the booms are put together we then walk (crane lingo for drive) the crane to the booms and attach them. Attention to detail is required when threading the cable between the booms as the cable plays an important role in redistributing the gravitational forces while also raising and lowering the boom when we lift the Super Ts. Finally, we load on the counter weights. Each counter weight is 20T with up to 80T attached to the crane and 160T on the superlift.

While all of this is happening, a crane pad is being constructed. For the Gore Highway, we are fortunate that it can be assembled to the side of the Gore Highway and still reach the bridge supports. The pad is made of compacted dirt and the crane sits on timber pads to distribute the loads applied to the crane pad over a larger area, reducing the bearing pressure on the compacted dirt. This provides a flat, stable and safe surface for the crane to work from.

After three days constructing the crane, we will then just pop the girders in to place as quickly as we can, and then start the process for dismantling the crane.