Better Engineering: Pierced Frame vs. Stacked

Imagine that you had the time, experience, and resources to build, rebuild, refine, work a trailer to safely do its job perfectly. That is what QuickLoadz is. I moved containers every day, empty, loaded. I still move containers. I am a general contractor, I am an honors engineer, I am in mobile storage. I have the time, machinery, money and experience to build the perfect trailer for moving sea shipping containers. So I do.

Everything in a QuickLoadz is built in a particular way for a reason.

I build our trailers with stacked cross members instead of pierced frame. Meaning that the cross members that make up the structure of the deck sit on top of the main beams instead of through slots cut into the main beams. I don’t like pierced beam trailer construction and won’t build one. Partly because I hate rust I won’t build a wooden deck trailer.

Why I won’t build a wooden deck trailer:

  1. Wood rots.
  2. Wood holds water against the steel, leading to rust.
  3. Every single place you put a screw through the cross member to hold down that wood, you create a place for it to rust out.
  4. Wood is dead weight compared to a steel deck. The steel deck welded to the cross members makes the bed a flexible truss, adding strength instead of taking it away.

But.. “What if I want to move tracked equipment and steel is slippery?” Simple, do what I and every other contractor does, put down 2 rough sawn wooden planks on top of your steel deck for tracked vehicles. We use tread plate on our decks which is much more expensive than slick steel but also allows you to drive pretty much anything on rubber up onto the deck. No other trailer manufacturer does that as a standard item.

Why I won’t build a pierced frame trailer:

The downside with pierced frame:

  1. You weaken the I beam because you never get complete welds all the way around your pierced cross members.
  2. You are putting a bunch of heat stress right next to the flange. They will crack there. I’ve heard the argument that you can use a larger I-beam. But that argument could only work with a wooden deck where the I-beam is flush with the top of the wood deck. But you weaken the I beam so much by putting holes all through the web it is a loser even with a wooden deck.
  3. You create a perfect place for rust to start.

What about lower deck height?

On a trailer with fixed wheels and a wooden deck and short axles you could lose a little height (maybe 2″) with pierced beam, because the axles don’t move you can have the wheels extend into the deck space by removing a couple of cross members and replacing the wooden deck above the fixed wheels with some steel plate.

But that is not true on a trailer with a steel deck. If you have a steel deck you would gain nothing by doing a pierced beam because the steel deck is only 3/16″ thick not 2″.

You also gain nothing on a trailer that has sliding axles. With sliding axles the moving wheels have to clear the cross members so you can’t lower the bed beyond the point the wheels can move under weight and not hit the cross members. Therefore there is no advantage in deck height for a sliding axle pierced beam and only downside.

Interested in talking? Call the CEO/founder/inventor:

Sean
888 304 3946 ext. 4

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