Hey guys
It's winter, or "vinter" as the boondockers around here say it.
One of the seasonal annoyances is "bubble run", when the ground is frozen and the tripod legs melt down, and the instrument is out of level and refusing to work. It usually happens when you are on your longest shot, hence the longest walk back.
The problem stems from, what I'm able to understand, the pressure on the legs which melt the frozen ground much like an ice skate, as well as the metal leg caps heating up and conducting heat to those points.
The solution has always been to "bank" the legs with snow, which is an effective way to stop it.
The problem is, like around here now, when there's no snow.
Yesterday I tried to "shadow" one leg with the total station box, and used a couple of rags for the other two, but that didn't work.
Does anyone have a solution to this problem other than using snow?
Thanks.
?ÿ
I lived in Chicago land for a winter.
We carried 3/4" pipe, or conduit. Drove 3 into ground, and set the feet in them. SOP.
N
I was taught by a surveyor with 35 yrs seniority, to hammer in 2x2 hubs and set up on them.?ÿ Never lost a bubble in freeze/thaw nor swampy goopy mud either.?ÿ Length of hubs was determined by conditions.?ÿ
no i do not, but have had the same problem for the last couple of weeks and am waiting for snow to solve it.
I was taught by a surveyor with 35 yrs seniority, to hammer in 2x2 hubs and set up on them.?ÿ Never lost a bubble in freeze/thaw nor swampy goopy mud either.?ÿ Length of hubs was determined by conditions.?ÿ
well ya that works fine when the ground isnt frozen, Trying to pound a 2" square hub in now just isnt going to happen. We have frost but no snow to cover the feet.
I was taught by a surveyor with 35 yrs seniority, to hammer in 2x2 hubs and set up on them.?ÿ Never lost a bubble in freeze/thaw nor swampy goopy mud either.?ÿ Length of hubs was determined by conditions.?ÿ
well ya that works fine when the ground isnt frozen, Trying to pound a 2" square hub in now just isnt going to happen. We have frost but no snow to cover the feet.
Understood.?ÿ?ÿ Nate's pipe idea would work even in frozen. I'm storing that one in case I need it some day.
This is a very common problem up in Canada, and I myself always used the 2 x 2 hubs to set the tripod on.?ÿ However, we always carried a concrete forming pin as well, to make the holes for them.?ÿ Also used to set Lathe up, in the middle of winter.?ÿ One more thing to carry around though.
A couple of boards with pre-drilled dimples will stop the problem. ?ÿJust don't bump them.
Pre-heat-melt the ground?
HC's boards sound effective and cheap when the only problem is sinking, not slipping.?ÿ The chain gadget or something similar improvised would be best for a hard, slippery surface.
I have used 6 inch sections of hardwood lath (not a lathe; way too bulky to carry around, and you often need 3 of them!) to keep the legs from sinking in hot pavement, and also for dealing with frozen soil, as mentioned by others.?ÿ If the ground is soft enough, a hub works well, but once we have some real cold nights, it seems the ground is too hard to use a hub, and somehow soft enough to cause major sinking issues.?ÿ Snow helps, but seldom seems to be available when needed.?ÿ
Ken
