Saturday, 28 January 2012

Halley 6 - first bit

In an earlier post (22nd Dec) on Halley 5,  I mentioned the two problems of building on a iceshelf - the constant accumulation (that plagued Halleys 1 to 4, but was overcome with Halley 5) and the flow of the ice to the coast where the only destiny is to become an iceberg - which is what would happen to Halley 5 if we didn't remove it first.

Halley 6 is designed to overcome both of these problems. Firstly it built on legs that keep the station out of the snow. Each leg is actually a large hydraulic ram, once a year, each leg can be sucked up in turn and snow bulldozed underneath; once every leg is on a new snow mound every leg is extended with the result that the whole station is lifted up a 1.5m higher than it was before.

Secondly, to overcome the inexorable movement to the coast, the whole station is made to be relocatable. The idea is that every 10 to 15 years the modules could be separated and towed to a new location. This would be a big job and we would need to rebuild all the towers etc - but it will be far easier and cheaper than building a new station.

HalleyVI in Jan 2010
We know the modules can be moved, because they were built in at the Halley V site and then dragged the 16km to the location for Halley VI.

The first module being towed in 2010/11

The biggest module being moved - nearly 200 tonnes.
More to follow....

Wednesday, 25 January 2012

More Antarctic exercise and saunas.

I have already talked about skiing and running but another very popular form of exercise at Halley this year is the Spinning bikes.

And what is better after a spin, ski or run than a sauna. Here is Penny in our sauna, it's built on site from waste materials but you wouldn't really know it - it works just as well as any sauna.

This is what it looks like on the outside.

The heater might look like a water heater and an old tool case but it works! And for the hardy there is plenty of snow to roll in outside.

Saturday, 21 January 2012

Big vehicles at Halley - part 2

The last post was mainly about our pullers and pushers. We have one type of puller left to talk about, the John Deere tractor, we have two of these.

John Deere Tractor

These have a special adaptation for Antarctica, with a Soucy track in place of each wheel. The John Deeres are very versatile, they can tow nearly as much as a Challenger, they can work in temperatures nearly as cold as a dozer, and they also can lift loads with their front forks.

Because we have so many loads to lift associated with the build of Halley VI and the demolition of Halley V, for the duration of the project we also have a JCB forklift, also with a track conversion.

JCB forklift

The JCB will be sent out at the end of the build/demolition, probably next year. Our biggest crane the Mantis will also be sent out at the same time.

Mantis Crane

The Mantis is our heaviest vehicle on the iceshelf - it weighs 24 tonnes and can lift 30 tonne loads. Once the Mantis has been sent out, we will still have two Nodwell cranes, capable of 5 tonne lifts.

Nodwell Crane
Although the Nodwells are far smaller cranes, they are far better at moving around on the snow. The other vehicle we have is the excavator, this is great for digging snow but the bucket can also be used for lifting small loads for which it is very quick.

How many times did you see Penny?

Wednesday, 18 January 2012

Big vehicles at Halley - part 1

In the previous post I showed the mobile elevated work platform, or cherry picker as its usually known. Halley always has lots of big vehicles, they are needed for lots of tasks like moving cargo from the coast to the station and pushing snow around the station. At the moment we have some extra vehicles to help build the new station and to demolish the old. So here is rundown of what we have. We have two Cat Challengers, they are our most powerful machines with 325HP 9L turbo diesel engines. They can tow 40 tonne loads and are fast, without a load they can reach 40km/hr. Unfortunately they are thirsty and can burn a 1L of fuel per minute! Like all our diesel engines here we run them on aviation diesel (called Avtur) which does not freeze or wax.

Cat Challenger
 The problem with the Challenges is that they can only really do one thing, that is tow heavy loads long distances in summer. The vehicle of choice in winter is a D5 dozer, metal tracks, engine heaters and simple engine management means it will work no matter how cold. It's very heavy at about 14 tonnes so it can pull heavy loads, but its very slow with a maximum speed of about 8km/hr. We have two dozers.

A D5 Dozer
The dozer can only really seat one person and it is too heavy for towing loads on seaice. Snowcats are lighter (our lightest being just 5 tonnes) and can carry people - our biggest seating 9 in comfort. Some snowcats have their engines at the back, like this one which is used to groom snow to make it smooth.

While some snowcats have the engines in the front. This one is towing a load on the seaice, the driver leaves the door open in case it breaks through the seaice (which doesn't happen very often!). In total we have eight snowcats.

Did you see Penny?

Saturday, 14 January 2012

Cherry Picking

Mobile elevated work platforms, or cherry pickers as they are known,  are very useful pieces of kit and extensively used at Halley for accessing high objects. One job we had this season was to cable up one of the large radars known as Superdarn. It  measures the position and velocity of charged particles in the Earth's ionosphere, the highest layer of the Earth's atmosphere. Because the movements of these particles are tied to the movements of the Earth's magnetic field which, in turn, extends into space, Superdarn provides scientists with information regarding the Earth's interaction with the space environment. The radar itself has 16 large antennas mounted on high towers, here is the cherry picker reaching up to one.

And here is Penny trying hard not to fall off one of the antennas while I work cabling up.

Wednesday, 11 January 2012

Small Vehicles at Halley

We have a large number of small vehicles at Halley. Mostly snow mobiles, more commonly known as skidoos. This is me riding an AlpineII skidoo between Halley V and Halley VI, we tend to ride around station without crash helmets but on journeys off station we wear crash helmets.

The sledge I am towing is colloquially known as the Pope Mobile, and very comfortable it is too. The Alpine II is quite pokey, 500cc engine. We have several differnt types of skidoo, the very comfortable Tundra (smaller 250cc engine).

And the fast Scandic, best of both worlds 500cc engine, double ski, single narrow track.

We also have a whole host of different sledges that we tow behind the skidoo, some for cargo and some for people - like the thing we call the happy sledge, which can take 8 people.

We also have a couple of tracked 4x4's, here are Sam and Neil having fun on one. They aren't as easy to maintain or use as a skidoo, are slower too, but they can haul bigger loads.

Did you see Penny?

Saturday, 7 January 2012

Planting trees

Halley VI is being completed, in the meantime most of the station facilities and power aren't yet available so the science team is concentrating on outside work. One of the tasks is to build an array of antennas for one of the scientific radars called the MFradar. To start with we had to survey the position of each of the antenna, for this we had to perform a sunshot to get true north so we could then use compasses and theodolites to mark the position of each antenna and its support pole. Here is Julius surveying.

Once we had flags marking the intended positions, we drilled holes using a ice drill.

And then lifted in the poles using a crane.

In total we planted 25 poles, here are some of them:

Friday, 6 January 2012

Tower Raising

This is our Clean area lab - known as CASLAB, it is used for air chemistry and for air to ice energy transfer studies. The whole area around it is kept very clean; normally no vehicles come within 1km of it and even then only in the direction that the wind doesn't blow from. About once every couple of years we have to use a crane to get new legs onto the CASLAB but we try very hard to do everything in the clean area without vehicles.

There is a tall tower next to the CASLAB, 31.5m high, which will have lots of scientific instruments placed upon it. Like all things at Halley, the snow accumulation reduces its height by about 1m or so a year and it needs raising to keep the instruments at the correct height.

This tower has a clever way of extending that doesn't need any vehicles. A frame is wrapped around the tower.

The tower sections are then unbolted from each other and the tower winched up in the frame.

Then a new section is bolted in the gap.

The frame is removed, and volia the Tower is now 1.5m higher at 33m. Here is the team - me, I am the one in the orange boiler suit and orange helmet.

Wednesday, 4 January 2012

Cats on Contrast.

Today I needed to drive the 16km from Halley VI back to Halley V in a snow cat. First thing in the morning was slightly foggy but with the sun nearly burning through - horizontal contrast poor, surface contrast good. This is the view from the snowcat, you can see clearly see the first drum of the drum line that I was following but the next drum and the horizon are very faint. The tracks of other vehicles that have driven the route are clearly visible.

Ok, I'll stop going on about contrast.

Tuesday, 3 January 2012

Back to school

Back to school - but not for me! Wishing all the children and teachers who go back to school this week the best of luck - especially those in Willingham.

This photo was taken in front of the big red living module of Halley VI. More on Halley VI in later posts.....

Monday, 2 January 2012

Antarctic Pixies

Halley is a remarkably sunny place - it actually gets more hours of sunshine than the UK, and of course most photographs tend to get taken on sunny days. When its cloudy or snowing then it gives a chance for the Antarctic Pixies to come out and play

Someone asked about how pilots can judge the ground, the answer is they need both horizontal and surface contrast. In the photo above you can't see the horizon which we call no horizontal contrast, you also can't see any details in the snow surface, so that's no surface contrast. When there is no horizontal or surface contrast you don't want to be landing planes! In fact even walking around can be tricky as you can trip over piles of snow without seeing them at all.

The photo below is still poor surface contrast (which is better than nil), but now has good horizontal contrast. The pilots land planes in those sort of conditions but only at sites they know are crevasse and sastrugi free. Sastrugi are irregularities in the surface of the snow caused by the wind.