Very nice morning today, sunny, not to warm, not to humid, kinda felt like Colorado. Noticed there was water dripping out of the outside door to my hot water heater when I went out to hook up and empty the grey and black water tanks on the trailer. Turns out the pressure-temperature relief valve was starting to fail. Rather than waiting until that happened I went to work trying to get the old one out. Easier said than done of course, as this was probably the original one that came new with the trailer 8 years ago. It wasn't until one of the other long term tenants came by with this huge honker of a crescent wrench that it finally twisted free. The best news is that I don't think I busted anything else getting it out either.

   Did some calling around, but so far no luck on a replacement. Will try 'Camping World' on my way to Asheville tomorrow. They had several in stock, but weren't sure it was the exact one I needed. Guess that means no shower for me tomorrow morning. Bummer!

   With that out of the way for the moment I went over and did a 'Boy's Night out at the Movies' trip and saw the new movie 'The Hunger Games'. Very interesting plot and well filmed. I couldn't help but think that the plot was somewhat smiler to a couple other movies I've seen, ie; The Time Machine, The Running Man, that episode of Star Trek where two planets were at war, but instead of actually fighting, they let a computer decide how many people on each side would theoretically be killed if it was real, and then they marched them off to be slaughtered by their own people, and probably several others I'll think about later. Still, it was entertaining enough and that was all I was looking for.

I hear that they are already starting to have wildfires back in Colorado. One SW of Denver had burned more than 3,000 acres already and killed a couple people as of this morning. I wonder if my brother Larry is involved with it in anyway? I'm sure he wants to be if he isn't.

   

    So this is the pedestrian bridge I was talking about yesterday. It's located at River Falls Park in downtown Greenville, SC and spans the Reedy River and the main falls on the river there. Looking at the picture you can see two support posts on the right hand side. Other than the abutment at each end of the bridge these are the only supports to hold the bridge up off the ground. So my first question was, where are the supports for holding up the 'other side' of the bridge?

  Looking up from the bottom you can see 3 large diameter cables running along the right side of the bridge. You can also see that the secondary support cables running down from the main suspension cable also come in on this side of the bridge. The other thing to notice is that the framework of the bridge deck is made up of triangular shaped metal trusses with the deep side also on this right side.

    So my thought is that the 3 cables, which run from one end of the bridge to the other, are under a very high tension load, which in effect wants to take the arched shape of the bridge and flatten it out or rotate it. Since these cables are at the bottom of the truss they would tend to try and tilt the left side of the bridge up but since the suspension cables are under tension from holding the weight of the structure up they want to tilt the left side of the bridge down. Hence the rotational up force from the 3 lower cables and the down force of the weight as well as the rotational force from the suspension cables the whole thing is in equilibrium. What an amazing balancing act... and who would of come up with this idea in the first place. I hope they got an award of some kind for it.

  So a final look from the top side and you can see part of the cable stay design. I must admit that you could feel vibration in the whole structure even when only a few people were walking on it. The whole project was wonderful done, the bridge is really beautiful, it spans across the river just downstream from the main falls and it's arc'd design makes sure the view of them is framed perfectly. The best part is I doubt 1 person in a 100, if that many, understands what a unique structure it is.