Just before I dash out for my bimble+overnighter this afternoon, I think I have a method of assessing the staying power of my pegs. I have gotten hold of a “fishermans hook” type balance that will measure weight up to 40kg. Although I could probably work it out eventually (I’m a brewer not a physicist!), if we convert kg into units of force we have roughly 1kg = 9.81 Newtons. At that point I have exhausted my pressure knowledge and leave it to others to further refine into KPa/Psi etc etc. Actually it doesnt really matter as long as we have something comparative to use as a yard stick for each type of peg….
Place peg into the ground vertically and all the way down until there remains just enough of the top of the peg to allow for guyline attachment (about 2cm). Rig up a simple loop of guyline and attach this to the top of the peg. Attach the other end of the guyline to the “hook” of the fishermans scales. Initial trials suggest for ease of doing this the line be fairly short (12 inches). In fact, you can use any-type of string or line for this, doesnt necessarily make a difference for the purpose of the test although it should be robust!!! Watching the scales, see what the maximum force is needed to put the peg out of the ground when pulling the fishermans scales up vertically. Also you can measure the force required to start to move the peg,etc etc…… Ok, this is a very blunt method of trying to estimate the “gripping power” of a peg but it gives an estimation
On a trial in the garden last night, I looked at the 3 pegs mentioned in my initial post and did some basic measurements. The ground was firm but stoney although I had no trouble pushing the pegs all the way in. The results as follows:
The titanium skewer peg took meaasured between 7 and 8 kg or approximately 70 to 80 Newtons of pressure to pull it out of the ground
The V peg took approximately 11 to 12kg or 110 to 120 Newtons of pressure to lift it out of the ground
The Y peg took approximately 10 to 11kg or 100 to 110 Newtons of pressure to pull it out of the ground
A couple of things then. It is very rough and ready, you are only seeing the gripping power of each peg with vertical force (real life puts multi-directional forces and strains on pegs) and the readout on the scales bounces around somewhat. Having said all that, my initial results seem to indicate that the V peg is slightly better than the Y peg and both are better than the skewer peg. I will take my scales and pegs with me this afternoon and try to find a few different ground types to test this method on (wet/boggy ground shouldnt be hard to find where I am going 🙂 )
Further, more elaborate, tests will follow when I have reviewed the initial measurements.
Round 1 to the V peg