Efficiently Shorten Your Boat Trailer for Winter Storage | 5" Aluminum I-Beams

[dacarls]

Now you are getting somewhere. Trimming edge of girders to 4.91 inches from 5 inches, while adding 1/4 inch Al plate - A problem? not to me, the "amateur but practical engineer". Just put another small piece of Al plate for a spacer on top of the (removable) tongue when it is replaced and before the tower bolts are retightened. This keeps it from collapsing 1/4 inch down onto the tongue.

 

[nvn]

pjm: Checker plate is too weak. It cannot be used as a replacement for the I-beam splice top plate. I-beam splice components are primary structural components, whereas checker plate is not. Furthermore, the rough surface of checker plate would cause uneven seating of the I-beam splice washers; the washers need to be perfectly level on a flat, smooth surface, to prevent prying on the bolt head.

 

[pjm]

pjm: Checker plate is too weak. It cannot be used as a replacement for the I-beam splice top plate. I-beam splice components are primary structural components, whereas checker plate is not. Furthermore, the rough surface of checker plate would cause uneven seating of the I-beam splice washers; the washers need to be perfectly level on a flat, smooth surface, to prevent prying on the bolt head.

NVN: OK I get the picture. Incidently, what was the reason for reducing the bolt size in your last message. Thanks again
PJM

 

[nvn]

pjm: The smaller the bolt size, the better (if adequate), because you want to remove as little of the I-beam flange material as possible. Even 0.3125-18 UNC, grade 8 bolts, torqued to 28 N*m (unlubricated), might work, and might be better, because they would remove less flange material. Or, if you use 0.3750-16 UNC bolts, intuition tells me you could probably omit one column of the bolts shown in post 49, which would still be twelve bolts holding each I-beam, instead of eighteen. And t1 = t2 = t3 = 5 mm might work.