The challenge was to create a vehicle that could confront four different mediums of travel:
- Float on water
- Motor through crushed ice
- Motor on icebergs
- Climb the whole vehicle out of water and onto an iceberg
This challenge is clearly immense and to achieve it we have had to create the worlds ultimate all terrain vehicle. In the 60’s, the Russians had a similar problem when their cosmonauts were landing in deepest Siberia and helicopters were not equipped at the time to fly in such horrendous conditions. Their solution was to create the first Archimedes screw vehicle, two screws which counter-rotate against each other so that the vehicle can be literally ‘screwed’ across the ground. Their vehicle however was very light as its only requirement was to pick up a couple of cosmonauts and bring them back.
Snowbirds challenge is far greater. The Bering Sea is moving at 3 miles an hour and therefore we need the ability to move very quickly – any delays would drift us North towards the Pole at an unacceptable rate.
Tracts have proved to be one of the most effective mediums of transport and indeed proved very successful on last years Expedition when we travelled a hundred and fifty miles up the coastline over a four thousand foot mountain range to get to the Bering Sea. To cover distances like this and rely solely on the screws would not be viable.
We needed to start with a base vehicle that had been designed to operate in cold temperatures and would be able to handle snow and ice. The obvious choice was a Piste Basher, a vehicle solely designed for ski resorts and able to handle exceedingly challenging terrain. Our particular Bombardier 160 runs on a Perkins 6 cylinder diesel which has been well designed to cope with these conditions.
Over the last couple of years the Ice Challenger Engineering Team have become the world experts in screw technology, and with the help of Southhampton University have designed the ultimate thread design. This will enable us to power our vehicle on screws by pulling a lever in the cab, which hydraulically drives down four arms lifting the trapped vehicle off the ground and leaving it to be solely powered by the rotating screws.
The screws themselves are made of aluminium 10mm thick and some 5 metres long and the threads have been finely designed to enable the vehicle to climb itself up out of the water on the cone shape at the front. It then grabs hold of the ice as the thread moves up the edge with the flights getting thicker and thicker so that the drive from the water is achieved towards the rear end. The screws themselves are driven by two hydraulic crane motors which offer a phenomenal 87% start up torque. This means that we can start spinning the screws from a standstill despite the seven ton weight of the machine pushing down on them. These Haagland motors are driven by a 100cc Sunstrand Pump which is fitted to the back of the piste basher engine. By use of a complex set of hydraulic valves we are able to finely tune the speed of which the cones rotate or if necessary rotate one in forward and one in reverse and make the vehicle track at 90 degrees to its forward motion (the rear of the drums are left bare with no screw thread). This is because we have discovered the longer the Helix are the less efficient they become. Finally, to enable the machine to cope with the vast screws we have built a space frame which goes over the top of the vehicle to create triangular location points for the chassis. The result is a strengthened machine able to take the arduous punishment that it is going to have to endure between America and Russia.
The front of the machine is fitted with a hydraulic wince which enables the vehicle to be pulled out. The rear of the machine is fitted with one buoyancy tank which can be lifted using a hydraulic ram. This enables us to change the trim of the whole vehicle in the water i.e. making the cones lift out of the water to enable them to engage anything up to a three foot step and therefore climb itself to safety. I would like to take this opportunity to thank the Ice Challenger Engineers whose substantial expertise has helped us to put Britain once more at the front of exploration.