Something that has always bothered me about reefer trailers

..can't have the tank forward of landing gear, a extentsion pipe though would be a help.

 

Where is this pipe going to run? Through holes in the crossmembers I suppose. But you can't angle it down the entire route to the tank so you may have backup issues. Personally I have no problem with it the way they are. It works and is dependable and less to break or have bottleneck issues of clogging or poor flow during fueling.

Plus, you could potentially fill the main tank 100% full, as well as the "filler pipe", eliminating any heat expansion void which could be a real problem

Something tells me this idea has been tried and abandoned long ago by various manufacturers.

 

You can mount a tank under the reefer unit like they do with rail containers. Makes it super easy to fuel the truck and reefer at the same time without pulling up. Only issue is with weight, leads to heavy drive axles sometimes.

If you had your own trailer if would be possible but you would also have to weld extra supports to hold the tank.

 

If the filler neck was higher than the top of the tank, any extra fuel up that filler neck would push out of the ventilation tube on top of fuel tank.
You want to see something really stupid? Take a look at how the oil filter screws onto the engine on carrier units. Sideways. Making it impossible to fill with oil before you put it on. Great engineering on that one there kubota. Only reason I can think of is this same engine is used in many different applications where that's the only way it will fit into the small tractor or whatever.

 

Probably has to do with not wanting a potential bomb in front of the landing gear directly behind the drive axles if a trailer got dropped. It also distributes the weight more evenly having the tank further back. Adding a few hundred more pounds to the nose in addition to the weight of the reefer unit would make for less nose weight and more on the back, which is not what you want.

 

I'm pretty sure the fuel system is designed the way it is in order to protect it from being damaged.

Putting any part of the fuel system in front of the landing gear makes it possible to destroy it during a high hook if you miss the pin.

Intermodal units do mount tanks directly under the reefer units, but stackable intermodal units have to be completely rectangular for storage on boats.

 

That means you might have to have a space without any freight in front of that trailer making it a nightmare to tie down, so you would be putting up load locks front and rear. Then on a oh-oh stop everything will be wanting to shift forward.