Tall loads

Platform trailers have 8 tires per axle line.

 

That load looks very similar to what I'm dealing with.

I did some thinking about this today. We are going to move it on site with a 12 line platform trailer. 12 lines aren't even loaded good with that kind of weight on-site but there is no way any state that I know of would let you take it down the road like that. We have hauled 240,000 LB on 6 lines but it was a very short haul ( less than 2 miles) and no bridges to cross.

I'm thinking two 10 lines may work, depending on each state's laws. Goldhofers run about 7,500 LB empty weight per axle line, that would be 230,000 + 150,000 = 380,000 LB or 19,000 LB per axle line. The only problem with that is you would need it mounted on bolsters on each end, increasing you height on a already too high load.

In my opinion, the US is way behind the times when it comes to platform trailers. Bridge loads aside, every state should allow you at least 40,000 LB per axle line. The way a platform trailer works, they will do far less damage to a road at 40K per line than say a fixed 3 axle group at 20K per axle. With the steerable axles of a platform trailer, you have virtually no scrubbing going around curves. You do get into concentrated bridge loads when you start really loading platform trailers but that can be solved with spacer decks or bolsters. Most platform trailers themselves are rated in the 30-35 metric ton range per line for capacity.

You also have to be really careful about grade changes when you start getting longer than around 12 lines. You have roughly 12" plus or minus suspension travel (actually +/- 300mm), you never want to bottom out or hyper extend a axle line when loaded. The frames aren't all that rigid and rely on equal loading of all lines to keep everything together.

Platform trailers also have a nasty habit of turning over if the operator isn't watching what he's doing with high CG loads. You've got to keep the platform level on high CG loads, if not you run the risk of overloading one side of the trailer and over she goes. Platform trailers are usually setup on a "three point" configuration. Without getting all technical, just imagine a 3 legged stool. This is mainly done to keep from twisting the trailer and making sure all axles carry the same load. You can set it up on a "four point" configuration which is more stable but this is mainly only used on job sites at very low speeds, due to axle overload concerns and the extra operator control to keep from overloading axles and platform twist.

 

The dollies you see in Solo's pic are nothing more than house moving dollies attached to a beam. They are mostly used to turn a platform trailer into a dual lane, to spread out the weight. You see them raised in the pic, they will be lowered whenever a bridge or other underground obstruction is encountered. They caster steer so will follow wherever the trailer takes them.

 

You could be right. I have zero experience with girder setups.

If setup like the pics above, it's pretty much going to be walking speed all the way across the country. You can get Goldhofers up to about 45 mph but not something with that high of CG.