Big Loads - Post Photos Number 2

A few pics of some of the other work I'm doing to the old girl while waiting for my rad...

 

Apart from throwing out some food everything's good. No smokey smells or damage what so ever. Got super lucky.

 

Snapped a few pics of the unload of today's beam...

 

I wonder how they decide if they are going to use concrete vs steel beams.

 

Because of the length of each span, a concrete beam would have had to been 15 feet tall. These are like 6 feet tall. This is on I15 in Helena and they are crossing 11 railroad tracks/sidings

The other thing to consider is the weight of the beams. Concrete beams run about 1000 pounds per foot on average. The 109 foot beam that I moved today was 49k and some change.

 

on another note, got some good news today....

 

Got chrome?

 

By my calculations, concrete beams should be about 100 times cheaper. Or why else wouldn't they just use steel beams for everything

 

Because the extra 9' of beam height on that stretch of road is unreasonable. MT is not flat and as easy to gradually build grade as TX. So the concrete beams may have been "cheaper" but the "cost" of re-elevating road grade would easily out way the beam cost difference.
Not to mention that concrete beams do not have the same life span in climates like Canada and the northern states. The freeze thaw cycles on the rebar inside the concrete develops condensation causing rust rot internally, reducing the structural integrity of the beams in a much shorter lifespan...blah blah blah, engineer talk...
Want an example, Google Nipigon bridge failure...oops
In northern climates, concrete beams are used for short spans only where little to no rebar reinforcement is required. Any span requiring significant quantities of rebar just use steel beams, the lifespan far outweighs the initial cost investment.

 

Well there is that and at 15 feet tall the weight for a 120' foot beam would probably be closer to 300k and the shipping cost would dwarf any cost savings on the concrete. We have hauled 120' beams before but they are not on the interstate spanning railroad tracks. The old bridge was part concrete and part steel, steel over the tracks. That may have more to do with it.