All right. So I had to dig a little more and find out whether this was really true or not. Like Andrew (DVS) I sort of felt like the supplier was giving me a load of crap and just trying to get out of warrantying their product. And also like Andrew, I wondered what would keep the block from sliding forward if it didn't have that lip. It just seems to make sense that the lip is there for more than just alignment purposes.
So I called one of the best structural engineering firms in town and talked to the principal engineer and owner of the firm. This is the firm we hire when we have to install the big complicated engineered SRW system. And I posed this question to him. He's one of the best structural engineers in our area. Here's what he told me.
Essentially, he told me that the supplier was correct. The lip there is only for alignment purposes. And it is not calculated into the equation for anything regarding structural stability. I posed the same question that Andrew asked above, "Ok. Then what is to keep the blocks from sliding forward then?" He said simply, "Gravity" He went on to explain that this is the difference between what we call a "gravity wall" vs. a "MSE wall". A gravity wall is constructed so that the force of the gravity of the blocks pushing down is stronger than the force of the hydrostatic pressure of from the soil pushing forward on the wall. He explained that the way a SRW gravity wall is installed, just the gravity and the batter on the wall make it strong enough to withstand the force pushing against the wall.
He went on to say that even the systems (like Keystone) that have the pins inside the block - even those are not for structural integrity. Those are only for alignment and to assure proper batter. That's all. They are also there to make it easier to attach geogrid. But they aren't taken into the equation for structural integrity at all. Just there to help you align the blocks properly when stacking. That's it.
So.....I guess you learn something new every day. I still find it hard to believe. But I gotta take his word for it. This is what he does. He's engineered more walls in this city than I've ever dreamed of installing and he's one of the best in the area. And he has no reason to lie to me. He's not at all connected with my manufacturer. So I gotta believe he knows what he's talking about - as hard as it is to believe.
The other thing I learned new today was that all of the 3 different brands of "Cuban" cigars I just brought back from my trip to the Caribbean last week are all fakes. Piss me off! Oh, well. I am still going to smoke those suckers. They look hella real to me. Here I went to all that effort to hide them from customs and everything. And they're fake! Oh well..... I honestly wouldn't have known the difference anyway. So I guess I'll go have a drink, smoke my fake cuban and think about the new things I learned today.