Victoria University core sampling rig in Antarctica fitted with Motus Hydraulic Cylinders
The cylinders seem to be coping well with the cold (only -20degc at this stage, we may get mid -30s early this season), with no leaking around the nose seals or cylinder creep due to oil passing piston seals. This year is the real test with the remainder of the hole to be drilled (we are currently at a depth of 130 metres with the target depth being 750 metres). We are using the main hydraulic cylinder to control drill penetration rate and this seems to be a successful strategy. The core breaks aren't very high yet with maximum pull down loads of around 400kg (although the cylinder sees twice this load), so easily within the cylinder limits so far, and unless we have problems the core breaks shouldn’t get too much more than this.
At this stage there has been no need to repair or replace items on the cylinders so we still have the spare rods and piston seal assemblies as supplied in Antarctica, touch wood we don’t need them. The hydraulic fluid we ended up using is Aero HF, a Mobil oil product used for aircraft hydraulics, mainly to get a usable viscosity at low temperatures.
"I’m certainly happy to recommend your product to others, and will keep you in mind for future projects"
Keep an eye out on the Victoria website for news on the project from mid October as we are due to go back to site for a four month season.
Just returned on Saturday from the Arctic, here are a few photos of your cylinders and our equipment in situ at NEEM north east Greenland (about 1400km from the pole).
Basic cylinder parameters are as follows
The 1500mm stroke trunnion mount cylinder can see peak pressures around 2850 PSI, flows are quite low from around 1 litre/min up to 4 litres/min provided by an enerpac single phase hydraulic power pack (this cylinder is our main mast extension cylinder inside the mast itself). This is used to control drilling cutting rate and also to provide additional power to break off ice core.
The 750mm stroke tilt cylinder will only see about 750-1000 PSI pressure at peak, flows will be anywhere between 0 - 4 litres /min via manual flow control simply to slow the stroke down to make it safe for people to work around the mast during operation.
Plan at this stage is to head down to Antarctica (Scott Base) early to mid October and then deploy to the field a couple or so weeks later to Roosevelt Island (eastern side of the Ross ice shelf about 700km due east of Scott Base), completing our drilling for this year around mid January with a further year to complete the Project. This also is logistics and weather dependent.
The drill is an Intermediate depth drill (drill design is a Copenhagen University development with Kiwi modifications) with the mast to go to 1000m (possibly 1500m in the future with upgrades). At Roosevelt Island the plan is about 750 to 780 metres, of continuous ice core to the bedrock giving about a 50 to 60,000 year high resolution record of climate and atmospheric gases.