I'm looking for a core drilling equipment with which i can have acces to steep areas. Does someone knowing were I can find this type of equipment? or a site with second-hand or used and reconditionated geotechnical drilling equipment.
coring (as in concrete), soil test boring or rock coring? and what in particular are you trying to do?--perform soil testing, identify "top of rock", or something else. there might be different options depending on what you're trying to do that might be much more cost effective and still provide "reliable" data (everybody's definition of reliable is different). also, there's always the option to hire a front end loader or trackhoe to construct a path along the slope (depending on how steep you're talking about).
For taking undisturbed soil samples. But I'm looking for something lighter to avoid making too much mess, because the drills must to be taken on private properties.
you could always try a tripod (never personally tried it myself but thought it might help your situation). i do not know how well it can retrieve shelby tubes (if at all) since i've never needed it for that use.
If you are drilling on "steep" slopes, I assume you will be encountering bedrock, of varying hardness, at some depth. A geoprobe or tripod rig will be of no help, they are intended for softer materials.
You will most likely need to core. There are rigs available, but they are few and far between and pricey. As a start, I suggest talking to some of the bigger exploratory drilling companies out there. Ruen Drilling and Cascade are a few that come to mind.
They have been around for years and have made light skid rigs that can go into difficult access. Many of these have an on-board cat-head or winch for snaking into bad areas.
I see their Bushmaster would appear to be what would do it for you.
I first used their equipment way back in 1954 and it held up well. I see they have expanded a lot since then.
Another old time company is Sprague and Henwood that used to have skid rigs.
See attachment. This little drill drilled through about 40 m of firm clay, then through about 30 m of bouldery/gravelly silt and into rock. Able to take "undisturbed" samples but not as good or convenient as with hydraulic push of bigger machine. In India we had similar machine that they would "tap tap tap" using small weight dropping "not too high". This little bugger, though, will go just about anywhere - and it breaks down into smaller pieces that they take apart and put back together again.