diagram that shows how a Clinebell-type ice block machine is kinda like an upside down freezing river. THIS Upside Down isn’t exactly Stranger Things, but it’s still pretty cool 😜
updated 7/29/23, mostly with seo and stuff, but also that ^ diagram
upside down freezing rivers? Is this sorcery?
When I was in Lülea, Sweden in early 2000 and in Bruges, Belgium in late 2000, I had the opportunity to carve blocks that I understood were from the Torne River, the same source that the original Ice Hotel in Jukkasjärvi, Sweden uses. The blocks were very large but clear, with more than a couple fractures.
At the time, they were the largest ice blocks I’d seen and truly enjoyable, but challenging, to carve. They struck me as giant, imperfect versions of the Clinebell-style blocks that I’d mostly worked with since I started sculpting. (Note: the first blocks I carved came from a knock-off of the Clinebell block machine, but it was the same process.) More recently, it occurred to me that the Clinebell freezing process essentially mimics the natural frozen river process, but it turns it upside down.
Rivers, of course, are always on the move, and they only freeze over when the air above them is cold enough for long enough. The freezing-over process is hampered by cold water’s tendency to sink. So just as the water near the river’s surface has reached temperatures where freezing in imminent, that water is moving toward the bottom of the river and being replaced by warmer water. This means all the the water in the river must be cooled before ice has a chance. (But it also means that there is a vertical circulation of water.)
In Clinebell machines, the cold comes from the tank bottom, as a pump circulates water from above. So water that gets cold would stay at the bottom and freeze, except for the pump circulation. If you start a block freezing without turning on the pump, you might notice that white ice quickly begins to form at the bottom. Turn the pump on, and the ice disappears until all the water in the tank is cold enough (and then it’s usually clear, not white.)
In both systems, the water circulation enables the ice to freeze clear. The circulation slows the freezing process somewhat and as the water moves across the slowly building ice, only water molecules bond to the growing crystal. Air and salts, which in still water (think ice cubes in a tray) would normally be trapped while crystals form around them, are carried away, leaving only the clear ice (this sort of freezing is somewhat of a water purification process.)
Pumping the water in the tank takes the place of the river water’s horizontal and vertical circulation, so the only major difference between the artificial system and the natural system (aside from fish) is the orientation of the cooling, leading to my Clinebell ice block machine characterization: An upside down freezing river in a box.
making an artificial Clinebell-type ice block is very similar to how these giant Alaskan ice blocks are made. An ice block machine though is like an upside down freezing river or pond, just in a small box.
Carvers who’ve been to Fairbanks, Alaska might quickly see a problem with my comparison. Clear blocks at the Ice Art Championships come from O’Grady’s Pond, not a river. So where’s the necessary circulation? Perhaps O’Grady’s Pond isn’t as still as I initially thought it was; Heather Brice told me that there may be some in and outflow through surrounding soils and a river is close by. She also told me that the ice “museum” at Chena Hot Springs has a different source, but the ice is still clear, so O’Grady’s Pond is not unique.
Mostly, however, I’d speculate that the vertical circulation created by the falling cold (and denser) water, combined with the very slow freezing process (Heather also reminded me that ice and snow above act as insulators and progressively slow the process,) is enough to keep the ice clear in a larger system such as a pond or lake. Because the pond doesn’t freeze solid top to bottom, there’s plenty of liquid water to keep air and minerals dissolved and out of the ice.
additional bits
I’d emailed Mike Clinebell some time back to ask him if he’d heard their block making process described as an “upside down freezing river” before. I was wondering if this sort of connection had played a part in the invention of the process. I didn’t hear back, but perhaps if I’ve missed something in this article, then someone at Clinebell Equipment Co. will take the time to suggest corrections. This time, at least, I’ve made sure that I’m spelling “Clinebell” correctly.
Also, I’d inquired before with Ice Alaska about how and why their blocks freeze so clear, but I didn’t hear back from them either. The last time I read, however, it sounds like they have plenty to deal with, as they may have to move the Ice Art event. I wish them plenty of luck and I hope it doesn’t hurt the event.
links and stuff
I’m thinking about adding this post to a collection on the science of ice. But you could also find photos and info from this entry on the ice sculpting secrets Instagram account or the facebook page. You can comment there as well as below. And if it won’t LET you comment below, then definitely comment on fb and/or IG. Thanks!
