This week at Davis: 8 July 2016

Over the 2015/2016 summer work commenced on the new hydroponics building for our station.

The footings were all that remained of the old hydro building that had been dismantled in prior seasons, so this was the starting point of the construction.

First the steel floor beams which support the container structure were installed, then the insulated panels to the underside of the floor beams were installed before the containers (two 20 footers and two 10 footers) were craned into position.

With the containers in position and locked down to the floor beam the cladding could commence. The cladding is the same 150mm thick insulated panels that they use for cool rooms back home but we want to keep the warm air in not out. With the wall cladding done, the trusses were made for the roof to provide fall so that any snow melt would run off the roof rather than pool (as it does in the TAD building). The trusses support the insulated panels that line the roof of hydro.

Site services were next to be connected to the building. With all the cladding on and the cappings, trims, stairs and door installed, it was the internal electrical rough-in next and then the internal linings. We started on this work but were stalled by the non-arrival of voyage 3 and the early retrieval of the summer crew, who had achieved most of the work to date.

When finished, the new hydro will produce easily three times the produce that we now get from the temporary hydro (see last week’s story).

Heaps of thanks to all the guys and gals that worked on this project, they did an outstanding job, had an eye for detail, always had a great ‘can do’ attitude, and were a pleasure to work and laugh with… to be continued.

Brett Sambrooks

This week we helped Dev celebrate his birthday — another one south!

Saturday night we lit the sparklers and piped out the cake in his honour.

Lesley outdid herself with a chocolate cake so chocolatey it was heaven — no one refused a slice!

Even though Davis is the least windiest station compared with Casey, Mawson and Macquarie Island, strong winds and gales can still make it particularly tricky to release weather balloons.

Under the influence of a strong low pressure system to the north, the wind speed here at Davis last Saturday afternoon began to steadily increase into the night. It peaked at 87km/hr at 1:09am and by the time Craig was ready to release the weather balloon the next morning at 6:15am it had lulled to 46km/hr.

Even in these winds it is possible for the radiosonde string to break, so there were precautions Craig had to take to guarantee a successful launch. In the air the radiosonde sits 20 meters under the weather balloon, suspended from thin string. If this thin string isn’t reinforced during a windy launch, the balloon will race off with the wind when it is released and jerk the radiosonde as the slack in the string is taken up, snapping the string. So the trick is to tie a couple of meters of stronger string between the radiosonde and the balloon, which will take the load when the radiosonde is jerked along by the balloon.

This is what Craig had to do last Sunday morning and it worked. The balloon launch was successful and data received from the radiosonde was ingested into weather forecasting models.

Craig Butsch