Building a Forest Bridge-Bridge Deck

With the steel superstructure nicely in place (whew!), it's time to finish the bridge. Half of the hemlock beams I ordered from a local sawmill arrived yesterday. The beams are 8" x 8" x 14' long. The ends are not cut square and they will have to each be drilled with 5 holes to accomodate the galvanized carriage bolts that will attach them to the steel superstructure. Each beam will be cut to length and temporarily set in place. The bottom of the beams will be marked through each bolt hole (in the steel beam), rolled and drilled. The beam will then be rolled back (top up), the bolts pounded through the beam, then the bolt tails will be set into the holes and the beam bolted into place. There are 26 beams.....

One week later...
The first half of the beams are in place..whew! They are too heavy to pick up alone (they are WET). They are almost too heavy to move at all. I placed them on the bridge steel with the tractor and then rolled them into place by hand. To get the overhang even on both ends, I have to bump the beams with my chest... The rest of the wood should be here at the beginning of this week.

Two weeks later....
The bridge deck is finished! The running boards were cut and nailed in place yesterday. The side rails were cut and placed but I need to locate 20" long carriage bolts to secure them to the bridge deck.

At the beginning of last week, I cut and stacked old railroad ties against the closer end of the steel and wood of the bridge so that I could backfill against them to raise the road grade to bridge level. I had to stack three ties on top of one another so the ties were drilled and 1/2" rebar pounded through them to keep the ties aligned.

To contain the fill on the sides of the ramp, I moved and stacked some very large rocks on either side leading up to the bridge. About 6 yards of gravel brought the road level about up to bridge level so that I could drive my tractor onto the bridge. With a bit of careful engineering, I placed two ramps at the other, yet to be filled, side of the bridge and got my tractor to the other side of the creek where I had to repeat the same operation to bring it to deck level.

Add a few loads of gravel to bring the road up to bridge grade and the bridge is done! I'm very happy with the way everything turned out. I was worried that a 20 ft. long, 14 ft wide bridge would look massive in this space but it ended up looking just fine. I have yet to find reasonably priced 20 inch long galvanized carriage bolts to secure the side rails to the deck. It's not a real high priority as I don't expect too much wild driving on our forest road.

There's a tinge of fall in the air...

I love the end of summer (okay, Jeff, which season don't you love?). I'll admit I enjoy the passing of the seasons.

The kids started school last week. Our youngest climbed on the bus for the first time with his sister and I'll admit I shed a few tears.

It's been an odd summer. What was supposed to be summer was wet. What was supposed to be spring was hot. Despite the strange weather, the tomatoes are coming in by the pound (I planted 6 different varieties) and the kids and I made a first batch of spagetti sauce using the Squeezo that I inherited from my folks. It seems to be missing the tomato screen which I will have to get. The first batch of sauce had a fair number of seeds in it which I re-screened through the pasta colander. The sauce was made with some of the last Walla Walla Sweets that I grew from seed for the first time and dried basil and thyme, also from our garden.

The garden was prolific this year and I managed to freeze some produce for a taste of garden fresh in the midst of winter. I'm getting better at it. Grass mulch keeps the weeds down pretty well but they still managed to get ahead of me late August. I also managed to get a second planting in of beans and lettuce. My goals this year were to both freeze and can stuff from the garden which I have done. There isn't much to show for my efforts but it is a start. We're up to our ears in tomatoes and cucumbers and I have made one batch of fresh gazpacho and will make another for the school's welcome back dinner next week. I'm contemplating pickles for next week as well as some stewed tomatoes for winter soup stock.

There's a tinge of fall in the air; there has been since the third week of August. Some of the soft maples have started turning and losing their leaves and there's a hint of yellow in many of the other tree species we have here in our area. Folks round here are saying that we're going to have an early winter. I'm not quite sure what that means, whether its just the cold temps or if it includes snow. I guess we'll see.

I've made a verbal commitment with a local farmer to harvest some of our poorer pine this winter. He uses oxen to haul the wood which is nice due to its minimal impact on the forest floor. After fixing skidder damage on our land, I'm leery of large equipment though if wood is properly harvested over frozen ground, there should be none of that type of damage. Given my choice, I'd much rather use this sustainable option. The farmer lives around the corner so he and his oxen will walk to work each day. Little fuel will be used to harvest and buck the wood. The logs will be yarded by the oxen to a point where they can be picked up and taken to a local mill by truck. Given the price of fuel, everyone here is looking to minimize fuel expenses which is fine by me as this means that folks are being forced to be a bit more sensible.

Quietly and quickly it seems, most of the birds have disappeared; heading south for the winter. I first noticed that our hummingbird feeder wasn't getting drained the last week in August and I didn't hear their high pitched squabbling. We had hummingbird babies for the first time since moving here. There have been a few flocks of Canadian geese heading off that way as well. We don't see too many as we are pretty far east and out of the flyway. There are still a few Mourning Doves around and of course the sparrows are still here too. Most all the others are gone and, if you listen, the crickets of late summer rule the airwaves.

The nights are good for sleeping. Open up the window, add an extra layer and sleep well in the coolness of the night. We almost had an early frost. One of my neighbors reported a frozen layer on her car. We didn't get it but soon it will be time to put the garden to bed.

Building a Forest Bridge-Steel Superstructure

With the footings in place and the stream bed re-finished, the 5 - 20 foot long, 1 foot tall steel I-beams could be set. You can see that the rebuilt stream bed has filled in and looks nice.

When the footing blocks were poured, 14" long steel anchor bolts were set into the blocks at locations that would secure 4 of the 5 beams. My intention was not that these bolts would rigidly secure the bridge to the footing blocks but hold the beams "in place" allowing some deck flexibility. Though I provided detailed drawings of bolt locations, the bolts ended up in different places than I'd anticipated. I had to cut the existing bolts off and drill about 12" into the blocks to epoxy half-inch threaded rod where I needed it to secure the beams.

Things don't always (don't ever?) go as expected and I like to have at least one alternative plan brewing. Initially, the beams were going to be set in place and the 3 sets of cross braces welded as the beams were placed in position. After rehashing this idea, I decided to move on to the more laborious and costly "plan B".

I rented a generator/welder (as opposed to hiring someone with a portable welder). Renting a portable stick welder was less expensive and, based on my limited welding experience from two welding classes, I figured I could do what I needed to. Plan B called for welding angle iron onto the beams (these would be pre-drilled to accept three bolts); then the cross braces would then be bolted to the angle iron as the bridge superstructure was assembled. This allowed me to weld the braces on to the beams while they were flat on the ground; a much easier task for one person to tackle by themselves.

Making the angle iron brackets took a while as I don't have any real metal working equipment in my workshop. 24 pieces of angle iron were cut with a sawzall. In each of these pieces then had to be drilled 3 - 5/8" holes.... yup, thats 72 holes in all (whew!). I have a small table top drill press for woodworking projects and I had to coax this little machine to drill through 1/4" steel. I wasn't finished drilling once these holes were done, I still had to drill (coax) an additional 72 matching holes through the cross braces. This approach added a bunch of time onto this project but in the long run it did help ease things on the assembly end. Keep in mind, I'm doing all this work by myself. The beams weigh in at over 500 lbs each and each of the cross-braces weigh about 20 lbs. So the strategy was to make the assembly job as easy for one person as I could and bolting was easier than vertical welding for me.

I decided to paint the I-beams instead of leaving them to rust (which they were already doing). A gallon of Rust-Oleum Rusty was about $30. at a local retailer. I put our generator in the back of my truck and used an orbital disk sander to clean the surfaces prior to painting on two coats of primer. One coat of brown topcoat applied with a small (4") disposable paint roller kit finished the beams. I don't know if the time I invested was worth it and this paint job will last or if it will inevitably make the steel last any longer but it satisfied my perfection-ist side and the bridge superstructure sure looks nice!

The I-beams were set, one by one, on top of the cement blocks, starting with the middle one and moving out to the sides. Sandwiched between the bottom of the beams and footing blocks were strips of tire tread cut from used radial tires (cut with a Sawzall). I figured this small bit of rubber would help absorb miscellaneous bridge flexing from traffic.

The top of each I-beam needed to be drilled with 26 bolt holes (130 holes in total). The bottom of each beam also needed to be drilled with two holes on each end to bolt to the footing block. The easiest way to do this was with a mag drill. A mag (magnetic) drill is a small (but heavy!) portable drill press that electro-magnetically secures itself to metal. I used a regular metal cutting 5/8" drill bit to bore through the beams. These holes will secure the bolts that hold the hemlock beams which create the bridge deck.

Steel is not as forgiving to work with as wood. All of my holes were precise to 1/16" of an inch and even then, I had to finesse the beams to get the bolts through the cross-ties and angle iron. First, the center three, drilled and painted beams were placed in position using the cross-ties as guides to precise placement. A shot of spray paint was squirted through the bottom holes to identify placement of the anchor bolts on the concrete blocks. The outside two beams were moved, holes drilled, threaded rod cut to fit and epoxyed in place. The center beam was not attached to the blocks because it sits over the joint between the two and the holed would have been too close to the edge of the block. The rubber tire pieces were similarly marked, holes drilled and placed over the rods. The beams were then placed and loosely bolted. The cross ties were also placed and bolted loosely.

The last two, outside beams were similarly placed and attached. When the entire bridge superstructure was assembled, all bolts were tightened. Scratches and hardware were touched up/painted to complete the superstructure. Though is was more costly (by about $500.00) and consumed more time than I had planned on spending, I am very pleased with the results. The first load of hemlock beams was delivered yesterday and it's on to finishing the bridge deck!