For anyone with a little interest, came across these recent articles quantifying ice growth, decay, mechanical stability and so on. Apparently some of the only serious academic investigations conducted in this area, if anyone knows of more please pass them on.
Although heavy reading, the articles may be of interest to some, whilst generally journalising relatively well known (but unproven) theories they are a useful reference for future winter conditions speculation that we are all so fond of here
Gauthier et al. 2013: Ice cascade growth and decay: a thermodynamic approach
http://www.researchgate.net/profile/Maurine_Montagnat/publication/258797149...
Weiss et al. 2011: Waterfall ice: mechanical stability of vertical structures
http://www.researchgate.net/profile/Maurine_Montagnat/publication/233492248...
Montagnat et al 2010: Waterfall ice: formation, structure and evolution
http://www.researchgate.net/profile/Maurine_Montagnat/publication/233582719... 
