Moving the Birdcage Hotel

I was driving past the Birdcage yesterday (not on my bike!) on my way home from an ARC meeting, as I was forced down the detour now in place while crucial parts of the Victoria Park flyover and tunnel project proceed. And there was a lot of people watching. I was stopped by the lights and took this snap on my cellphone. TV was much better. But I liked the attention of these young skate-boarders. The pub will be shifted twice: now up Franklin Rd on a slight angle to the south to avoid street trees while the tunnel is being built and then three to four months later back to its original site above the tunnel's roof.

The following info I gleaned from a June NZ Herald article:

Work is well-advanced to strengthen it for the shift, bolting 1.8cm thick plywood to walls, steel reinforcing rods being run through the bricks and building new structural walls on the exterior.

Those walls are rising atop the existing brick plaster-clad walls on three sides of the building.

The structural walls will help hold the hotel together ready for the move and in case of earthquakes.

Thornton said that towards the end of the job, plaster would be applied over the top of the reinforcing so the walls would appear as they did before any of the work started.

But the basement is a big focus for the workforce now, with excavations around exterior and interior walls.

The ground floor has been gutted from the inside to allow access to the footings and for structural strengthening.

Brick walls are being vertically stressed with high-tensile bars inserted through holes core-drilled from the top of the building, then tightened up.

The rear non-heritage walls of the building are being coated with reinforcing concrete so these act as sheer bracing walls.

Carbon fibre reinforcing strips are being inserted into the chimney walls to provide seismic strengthening.

Concrete sandwich beams are being inserted under the building and those will soon sit on top of sliding bearings that will carry the Rob Roy along runway beams to its new temporary home and back again.

To transfer the building load on to the runway beams, hydraulic flat jacks will be inserted between the sandwich beams and the runway beams at 14 points, Thornton said.

These jacks will be monitored every metre to ensure that all points of the building remain level as it moves, he said.

Beneath each flat jack will be a sliding bearing made of a low-friction Teflon puck that will slide along a stainless steel strip fixed to the top surface of each runway beam.

The jacks will be incrementally loaded until the building's entire weight is transferred from its existing foundations on to the new beam system, Thornton said.

Irving said the building was not being lifted up. Hydraulic pushing rams will be installed between the building and the runway beams to provide the moving force. Each stroke of the rams will move the building forward by about 1.5m at a time.

While the tunnel is built under its original site, the Rob Roy will sit on temporary foundations 40m up Franklin Rd.

The transport process will be repeated when the building is moved back after the tunnel construction.

So. Engineers can do anything. And about time we took heritage seriously, as well as urban design around these massive state highway projects. About time they were shoe-horned into the city fabric, rather than the city being demolised to make way for the roadway. Good on you Richard Reid (Landscape Architect) who advocated tirelessly for this approach to the Birdcage.